,transcriber's notes3 ,in this transcription1 paired underscores denote italicised text4 ,archaic spellings such as #8sedementary' and #8millepedes' have not been altered1 and the following spelling inconsistencies have also been left as in the original text3 omnivorous_/omnivorus1 eleagnus_/elagnus1 silverfish_/silver-fish1 woodlice_/wood-lice1 blowfly_/blow-fly4 ,the following typographic errors have been corrected3 kindom -- kingdom aphis lion -- aphis-lion ,jose -- ,jos ocurring -- occurring necesary -- necessary ,crytolmus -- ,cryptolmus ,crape -- ,grape pupuli -- populi ,,cawthron ,,institute ,,monographs ,,garden ,,pests in ,,new ,,zealand ,a ,popular ,manual for ,practical ,gardeners1 ,farmers and ,schools ,by ,,dr4 ,d4 ,,miller ,ph4,d41 ,m4,sc41 ,f4,r4,s4,n4,z41 ,f4,r4,e4,s4 ,assistant ,director and ,chief ,entomologist1 ,cawthron ,institute1 ,nelson ,,contents4 ,page ,introduction #e ,chapter i43 ,general ,review of the ,animal ,kingdom #g ,chapter ii43 ,soil ,organisms and ,soil ,fertility #ab ,chapter iii43 ,structure of ,insects #ag ,chapter iv43 ,life ,histories of ,insects #bb ,chapter v43 ,sucking ,insects #bi ,chapter vi43 ,sucking ,insects 7,concluded7 #db ,chapter vii43 ,leaf-feeding ,insects #ej ,chapter viii43 ,boring and ,underground ,insects #fa ,chapter ix43 ,miscellaneous ,pests #fg ,chapter x43 ,principles of ,pest ,control #gd ,index #ha ,introduction ,this work deals with the insects and other animals having a detrimental or beneficial influence upon horticulture in ,new ,zealand4 ,its purpose is to supply such general information as will enable the common animal inhabitants of the garden to be identified and controlled1 to act as a popular guide for the use of practical gardeners and schools1 and at the same time serve as a source from which the examination requirements set out in the syllabus of the ,new ,zealand ,institute of ,horticulture may be met4 ,as this work is for the benefit of the gardening public1 and an endeavour to diffuse some knowledge of certain natural problems1 the language of the scientist--which1 unfortunately1 tends to guard what is known of these problems from the general reader--has been avoided as much as possible2 at times1 however1 this ideal cannot be adhered to1 but in such cases the reader should find no difficulty1 and should be prepared to become familiar1 with the few terms used4 ,to know the scientific names of animals without being acquainted with the animals themselves is a habit to be avoided1 and is just about as instructive as memorising the names of people in a town or telephone directory4 ,but animals must be named2 though their popular names are used in the following pages and as such names are very often misleading1 the scientific names are given in brackets in order to avoid confusion4 ,in such a work as this1 illustrations are of great value1 and these are given wherever possible4 ,one drawback to illustrations is that the relative proportions of animals may be lost2 for example1 a microscopic organism might require magnification by some #d1jjj times its natural size and so become equal to that of some of the most conspicuous insects4 ,even with the best illustrations1 however1 it is essential that the reader becomes familiar with the animals themselves4 ,this should present no difficulty to the reader1 since he will find in his garden all of the animals with which he is concerned--mostly insects and their near relatives4 ,further1 of very great assistance to him1 he will find the several excellent public museums throughout the country1 as well as the specialists at such research institutions as the ,cawthron ,institute at ,nelson4 ,to keep a work for the general reader in a readable form1 the desire of the author to cite the sources from which he derives his information must be suppressed4 ,if this were not done1 the text would rapidly become littered with endless references1 much to the weariness and confusion of the reader4 ,therefore1 it should be remembered that a work of this kind is a compilation from the publications of many scientists1 to which is added what little original information the writer himself might possess4 ,opportunity must be taken here to express one's appreciation of the assistance given by ,mr4 ,w4 ,c4 ,davies and ,mr4 ,l4 ,j4 ,dumbleton in the preparation of the photographs and drawings1 respectively4 ,,chapter ,i4 ,general ,review of the ,animal ,kingdom4 ,at the outset it is advisable1 by reviewing the animal kingdom as a whole1 to secure in perspective the relationships of the animals with which the horticulturist has to deal4 ,to most people the animal kingdom is comprised chiefly of those animals commonly met with in everyday life or in general reading--the game and domestic animals and the fishes1 all of which are similar in that they possess a backbone or vertebral column1 and are consequently known as the vertebrates4 ,popularly1 however1 they are generally classed as the 8lower0 and 8higher0 animals2 there is certainly some accuracy in such a haphazard classification1 since1 though all the vertebrates are1 strictly speaking1 the 8higher0 animals1 some are 8lower0 7e4g41 fish1 frog1 and bird7 than others 7e4g41 kangaroo1 dog1 and man1 the highest of all74 ,but when it comes to the true 8lower0 animals1 that vast assemblage of less conspicuous creatures1 the jelly-fish and corals1 worms of all kinds1 sea-urchins1 crayfish1 wood-lice1 spiders and insects1 shell-fish and snails1 all characterised by the absence of a vertebral column and known as the invertebrates1 they are not collectively visualised in a general sense as are the vertebrates4 ,as a rule1 these invertebrates are known individually as independent units1 except1 perhaps1 in the case of worms1 insects1 spiders1 wood-lice1 etc41 which are very often collectively and haphazardly referred to as 8insects10 a term1 in this sense1 as ill-defined as it is unlimited4 ,that the average person should be more conversant with the vertebrates than the invertebrates is1 to a great extent1 the natural outcome of association and training2 a possible influence is to be found at the outset of one's career in the many illustrated nursery books depicting game and domestic animals1 but seldom1 if ever1 any of the invertebrates2 and this impression tends to be further fostered in later life by visits to the zoo1 where we meet in person most of the nursery book animals1 and perhaps some of the lower forms1 such as insects2 but the latter1 in most cases1 are there by chance1 not design1 and against the will of the authorities4 ,in recent years1 however1 more public attention has been given to the lower animals owing to the detrimental influence of many upon agricultural development as well as upon public health4 ,that such animals are capable of ranking as fundamental factors hindering human progress1 may be realised when it is considered that1 of the invertebrates1 insects alone comprise nearly four-fifths of the whole animal kingdom6 ,this has been graphically illustrated as follows by ,f4 ,e4 ,lutz1 of the ,american ,museum of ,natural ,history3--,extend the arms and fingers at right angles to the body1 and let the distance from the tip of the middle finger of one hand to that of the other represent the number of different kinds of living animals2 then the last joint of the middle finger of the right hand will be proportionate to the number of mammals 7kangaroos1 hoofed animals1 rabbits1 man1 etc471 the second joint to the reptiles and their relations1 the first joint to the birds1 and the distance between the knuckles and the wrist to the fishes4 8,in other words1 you can hold the so-called zoological gardens and their aquarium annexes in one hand40 ,finally1 the distance between the wrist of the right arm and the tip of the middle finger of the left will proportionately represent all the known species of invertebrates1 and of this section of the extended arms all except between a wrist and an elbow will be insects4 ,the zoologist classifies the animals under twelve main divisions1 of which eleven contain the invertebrates and one the vertebrates2 these divisions are arranged in a series1 the first containing the simplest or lower animals1 and the last the most complex or highest4 ,a glance at this classification will serve to give some idea of the relative position in the animal kingdom of the animals which will be dealt with in the following pages4 ,the very lowest forms1 belonging to the first division1 are micro-organisms known as the ,protozoa2 they inhabit water and soil1 and live upon their own kind or upon minute plants1 including bacteria1 or are parasitic upon the higher animals1 some of these parasites causing such diseases as malaria4 ,the ,protozoa are single units of living matter 7protoplasm71 and may be referred to as the one-celled animals2 they are mostly microscopic1 and lead an independent life1 or are associated in colonies1 but are capable1 as a rule1 of carrying on independently all the functions of life1 though there are no organs such as those of digestion1 respiration1 and circulation1 as we know them in the higher animals4 ,it is amongst such simple forms that the distinction between the lowest animals and plants ceases to be clear4 ,as will be discussed later1 there is evidence that certain ,protozoa have an important influence on soil fertility4 ,the remaining eleven divisions contain all other animals1 ranging in size from mere specks to the mass of the elephant2 the bodies of these are built up of a complex aggregate of countless cells of protoplasm arranged in groups to form the organs of digestion1 circulation1 respiration1 reproduction1 etc41 each having its definite function in the animals' lives4 ,the following are some typical or well-known examples of each of these divisions1 the technical names1 with the exception of the ,protozoa1 not being given3-- ,the ,protozoa 7reference should be made here to ,fig4 #a7 are followed by 7#b7 sponges2 7#c7 jelly-fish1 sea-anemones1 corals2 7#d7 flat worms 7tape-worms1 etc472 7#e7 round worms 7thread-worms1 eel-worms72 7#f7 sea-mats1 lamp-shells2 7#g7 wheel-animalcules2 7#h7 star-fish1 sea-urchins2 7#i7 segmented worms 7earthworms72 7#aj7 crayfish1 woodlice1 centipedes1 millepedes1 spiders1 mites1 insects2 7#aa7 shell-fish1 slugs1 snails2 7#ab7 fish1 frogs1 lizards1 birds1 hedgehogs1 rabbits1 man4 ,so far we have reviewed the animal kingdom from one aspect only--that of classification1 based on the resemblances and differences of the individuals4 ,it is now necessary to look at the subject from the viewpoint of the horticulturist--that is1 the relationships of the animals to their surroundings1 or environment1 and to the welfare of man4 ,of the two great life-groups--animals and plants--the plants are of fundamental importance2 without them no animal could exist1 since1 of all living things1 it is the green plants alone that are able to convert the inorganic chemical constituents in soil1 air and water into living matter or protoplasm2 and all animals1 either directly or indirectly1 are dependent upon plants for their food supply4 ,plants1 therefore1 may be looked upon as the primary producers of life1 and animals as the consumers4 ,it is in this respect that the horticulturist becomes interested1 in that certain of these consumers destroy too many of the plants grown by him for other purposes2 fortunately1 not all of the consumers are destructive2 many are of very great use to the horticulturist and mankind in general4 ,the last point is well illustrated by the following classification of the animal kingdom based upon the part it plays in human welfare2 this is a modification of the scheme adopted by the ,british ,museum of ,natural ,history3-- ,group ,i4--,wild or domesticated animals used by man as beasts of burden1 source of food1 or in the manufacture of various products--e4g41 sponges1 crayfish1 bees1 silk-worms1 shell-fish1 and various vertebrates1 as fish1 birds and mammals4 ,group ,,ii4--,animals detrimental to man's welfare1 attacking man himself2 animals and plants of value to him1 or the products derived therefrom--e4g41 ,protozoa1 parasitic worms1 mites1 insects1 and such vertebrates as certain birds and mammals4 ,group ,,iii4--,animals aiding man's welfare1 as scavengers1 or by pollinating flowers1 or by attacking and checking such animals as are included in ,group ,,ii4--e4g41 ,protozoa1 parasitic worms1 earthworms1 parasitic insects1 spiders1 and such vertebrates as certain birds and mammals4 ,an analysis of the above classification shows that animals both aid and hinder the progress of man1 hence the use of the terms 8beneficial0 and 8destructive40 ,in nature1 however1 these terms are not altogether applicable in the same sense1 since the balance maintained between animals and plants under natural conditions is an extremely fluctuating one1 though sufficient for natural purposes2 with man1 however1 the case is different4 ,in order to compete in the world's markets1 and to supply the growing demands of increasing population1 a much higher and dependable standard of productivity is required than is found in nature4 ,consequently1 whilst utilising1 and increasing the efficiency of the so-called natural enemies as auxiliaries in his fight against destructive animals1 man has found it necessary to develop an effective system of artificial control1 involving chemicals1 resistant plants1 cultivation1 crop rotation1 etc41 for the purpose of maintaining a more stringent balance to meet his requirements4 ,historical ,review of ,new ,zealand ,conditions4 ,the animal population of ,european ,new ,zealand is very different from that of pre-,european times1 a position brought about naturally enough by the changes resulting from agricultural development as practised in the ,old ,world1 and the consequent creation of an environment foreign to the country4 ,though the official date of the settlement of ,new ,zealand by ,europeans is #ahdj1 the influences1 inaugurating that upheaval of the natural conditions which was later to have such a marked effect on the economic development of the country1 had commenced many years earlier4 ,illustration3 ,fig4 #a4--,some common animals grouped to represent the twelve main divisions of the animal kingdom4 ,when the first ,europeans set foot in ,new ,zealand1 they must have been impressed by their unique surroundings1 totally different from anything to be met with in the ,old ,world4 ,they found the country dominated by a forest quite unlike the forests of any other land1 and inhabited by an animal population presenting many unusual features4 ,this terrestrial population was characterised by an abundance of insects and spiders1 and a paucity of vertebrates excepting the birds2 the vertebrates consisted of a species or two of frogs1 a few species of lizards1 some #bjj species of birds1 and two species of bats1 the last being the only terrestrial mammals4 ,in fact1 the insects1 spiders and birds were the dominant animals1 a feature common to other parts of the world1 but the scanty vertebrate population1 other than birds1 was a characteristic of primeval ,new ,zealand4 ,new ,zealand being a country fitted for agriculture1 settlement by ,europeans naturally resulted in extensive and rapid changes1 since the settlers brought with them the knowledge1 implements1 animals and plants of the civilised world2 and to make way for settlement1 it was necessary to remove the forests and drain the swamps1 and to replace them with cultivated crops and pastures4 ,these activities have been so thorough1 that1 within a period of some #ij years practically the whole of the original ,north ,island forests1 and the greater part of those of the ,south ,island1 have been cleared4 ,an outstanding feature of these changes is that many of the pests associated with the agricultural animals and plants have been brought to ,new ,zealand with the animals and plants they infest1 and these exotic pests comprise by far the greater proportion of the destructive animal population1 there being but few native species forming the balance4 ,for example1 #ga per cent4 of the destructive insects are exotic1 and #bi per cent4 native1 while all the parasitic worms of economic importance1 all the destructive birds 7e4g41 sparrows7 and mammals 7e4g41 deer1 wild pigs1 and goats7 are introduced4 ,the exotic factors that have set up this new environment may be summarised as follows3-- 7#a7 ,clearing of the native vegetation4 7#b7 ,introduced plants3 e4g41 grasses1 forage crops1 trees1 etc4 7#c7 ,introduced game animals3 e4g41 deer1 pigs1 rabbits1 birds1 etc4 7#d7 ,introduced destructive animals1 infesting animals and plants of economic value3 e4g41 parasitic worms1 insects1 etc4 7#e7 ,animals imported to control pests1 but which have become destructive themselves3 e4g41 weasels1 birds4 ,,chapter ,,ii4 ,soil ,organisms and ,soil ,fertility4 ,in the first chapter the plants were referred to as the primary producers of life1 and the animals as the consumers2 the former not only furnish nourishment for their own growth1 but also for the support of the animal world as a whole4 ,living plants 7in reference to green plants7 utilise the sun's energy in the manufacture of their complex food materials from comparatively simple chemical compounds4 ,these latter compounds are carbon dioxide1 derived from the air through the agency of leaves1 and a weak solution of various chemical compounds in water1 derived by means of the roots from the soil1 and carried up through the plant to the leaves1 where the elaboration into the complex compounds to be utilised by the plants as food takes place4 ,these comparatively simple compounds from which the plants elaborate their nourishment are the raw food materials1 and that they must always be available for plant growth1 is evident when one considers the vast areas of vegetation that cover1 with the exception of desert regions1 the surface of the earth4 ,under moist climatic conditions it has been calculated that some #ejj tons of carbon dioxide and #a1jjj1jjj tons of water1 having the raw food materials in solution1 are used annually by one square mile of dense forest4 ,for their development1 therefore1 plants require3-- 7#a7 ,sunlight as the source of energy for the carrying on of their life functions2 7#b7 ,air for the supply of carbon dioxide1 oxygen1 and1 indirectly1 nitrogen2 7#c7 ,an ample supply of water required for the living tissues and as a vehicle for the transport from the soil of 7#d7 ,the raw food materials1 in the form of various chemical compounds4 ,with the exception of the carbon dioxide derived from the air1 all the raw food materials--water1 nitrates1 phosphates1 sulphates1 potassium1 calcium1 magnesium1 iron1 etc4--are present in the soil1 though only a part of them is in a form suitable for imbibition by plants4 ,in the formation of these food materials1 which render the soil fertile1 physical forces and the activities of living organisms play a leading part4 ,our immediate concern is with the influence of these organisms upon soil fertility1 but it is advisable to give some consideration to the soil itself1 since it is the environment in which the organisms live1 and with which their existence is intimately associated2 in this respect attention will be confined to the type of soil usually cultivated by the horticulturist1 and to the uppermost layers--that is1 approximately1 within one foot of the surface4 ,soil is the product of disintegrated and weathered rocks with which are mixed the residues of organic matter4 ,apart from the particles of disintegrated rocks1 which form the matrix1 soil contains chemical compounds of two kinds3 those of a purely mineral nature derived from the inorganic components of the original rocks1 and those of an organic origin derived either from the ancient remains of organisms1 which1 in the case of sedementary deposits1 became incorporated in the rocks at the time of their origin1 or from the remains of present-day plants and animals decomposed by soil organisms4 ,in addition1 there is the humus1 which has a fundamental physical influence1 and for the production of which soil organisms are responsible4 ,illustration3 ,figure #b ,,the ,,three ,,main ,,types ,,of ,,soil ,,protozoa4 ,magnified #cjj-djj4 ,in the initial stages of soil formation during the disintegration and decomposition of rocks1 the first type of soil to be formed is suitable for the growth of only certain plants2 it is of a purely mineral nature1 containing raw food materials derived mainly from the rocks and not from organic matter1 unless from such organic residues as were incorporated in the rocks during their formation in ancient times4 ,such soil cannot sustain the higher types of green plants1 nor is it populated by soil organisms2 it furnishes suitable pabulum1 however1 for the nourishment and growth of the more lowly types of vegetation1 which are able to convert to their benefit the limited supply of food materials available4 ,the complex organic compounds that such primitive plants elaborate from these food materials of purely mineral origin1 and incorporate in their tissues1 are1 after death1 returned to the soil1 which becomes correspondingly enriched1 and a favourable environment for the establishment of organisms2 the latter reduce these plant residues to humus1 and during this process of decomposition produce food materials of an organic origin suitable for the nutrition of the sequential plant covering4 ,so the process proceeds until a soil is formed of sufficient extent and quality for the support of a more extensive and increasingly complex vegetation2 thus1 in the cycle of life and decay1 stores of organic compounds are elaborated by plants and returned to the soil1 which they enrich1 and where they are decomposed by organisms1 and so maintain the supplies of food materials suitable for the maintenance of vegetation4 ,these phenomena of plant establishment and succession1 correlated with soil formation1 were clearly demonstrated by the re-establishment of vegetation after the soil and plant life had been destroyed by the historic eruption in #ahhc of ,krakatoa1 a volcanic island in the ,straits of ,sunda1 between ,java and ,sumatra4 ,the first plants to be established on the volcanic deposits were species of terrestrial alg1 which gradually spread and built up soil suitable for the development of soil organisms and for the growth of seeds brought to the island by birds and ocean currents4 ,so rapid were the changes brought about by these influences1 that within a period of twenty years after the eruption the barren ground was reclothed by a dense and varied plant covering4 ,organisms that form part of the organic complex of the soil range from the more conspicuous species1 such as slugs and snails1 insects1 spiders1 wood lice1 millepedes1 earthworms and eelworms1 to such microscopic forms as protozoa1 fungi1 alg and bacteria1 the last three being members of the plant kingdom4 ,these organisms may be grouped as follows3-- 7#a7 ,temporary inhabitants that enter the soil for shelter1 or to feed as scavengers on decaying organic matter1 or both--e4g41 slugs1 snails1 wood lice1 certain insects and some eelworms4 7#b7 ,permanent inhabitants that are dependent on the soil for their development and supplies of food1 either throughout or during most of their lives--e4g41 certain insects and spiders1 millepedes1 earthworms1 eelworms1 protozoa1 fungi1 alg and bacteria4 ,the organisms in the first group play a comparatively minor part in soil development1 and influence its fertility to an almost negligible extent1 the temporary scavengers1 perhaps1 being of more importance since they aid in the reduction of vegetable residues4 ,the forms in the second group1 however1 are invaluable as soil-making agents and in the production of plant food materials1 the least important among them being the insects1 spiders and millepedes4 ,many are merely scavengers1 but some insects1 such as grass-grubs and the caterpillars of certain moths1 and millepedes1 feed upon living plants and so add organic matter to the soil in their excreta1 which also contains quantities of soil swallowed with the food1 this latter mechanical action aiding in the pulverising and opening up of the soil2 certain eelworms1 too1 that attack living plants play a somewhat similar part1 in that they are primary causative agents in the decay of healthy tissues4 ,other forms of insects1 together with spiders and some eelworms1 are predaceous upon their fellows1 the remains of the latter being added to the soil residual complex4 ,apart from the activities of all these organisms1 however1 it is the earthworms1 protozoa1 fungi1 alg and bacteria that have the most fundamental influence upon soil fertility4 ,earthworms may be correctly called the great soil builders2 they burrow through it1 allowing the free passage of air and water2 they swallow large quantities1 which they eject on the surface in the form of 8worm-casts10 the soil materials being well mixed in the process2 they pull underground leaves and other parts of plants from the surface and so increase the supply of organic matter for the action of the micro-organisms that bring about decomposition4 ,further1 by depositing their 8casts0 on the surface1 earthworms soon cover the accumulations of dead vegetable matter1 as has been illustrated by ,darwin in his classic work on these animals4 ,without the aid of earthworms--e4g41 in sour soils in which they do not abound--the plant residues accumulate on the surface1 to form a partially decomposed1 peaty mass1 which only a limited number of plants can tolerate4 ,the protozoa1 fungi1 alg and bacteria are all microscopic organisms1 and are the agents responsible for the decomposition of the organic residues in the soil2 they do not act as independent units1 the processes of one group being dependent upon and intimately related with those of the others4 ,during the activities of these organisms various organic and mineral substances are decomposed or transformed into materials1 such as humus and the inorganic compounds of nitrogen1 phosphorus1 potassium1 etc41 necessary or helpful for the growth of plants4 ,the protozoa 7see ,chapter ,i47 are the lowest and simplest forms of animal life1 being mere specks of living matter4 ,three different groups of soil protozoa occur 7,fig4 #b74 ,some1 like the amba1 progress by streaming movements1 extruding temporary extensions of their substance in the form of finger or thread-like processes2 the bodies of such protozoa may be naked1 or enclosed in a shell-like covering secreted by the organism itself1 or protected by an accumulation of particles of foreign matter4 ,some have a body of more definite shape and progress by means of the whip-like action of one or two thread-like processes1 or flagella1 arising from one end of the body4 ,such forms are the most numerous in the soil4 ,others1 also of definite shape1 control their movements by means of short1 hair-like processes1 or cilia1 either distributed over the body or restricted to definite regions4 ,the protozoa are widely distributed1 being most abundant in the richer types of soil1 especially during the spring and autumn4 ,a great amount of research has been undertaken at ,rothamsted1 ,england1 and elsewhere1 on the part played by protozoa in soil fertility2 the evidence thus secured points to the probability that some of these organisms may be detrimental in that they devour certain kinds of bacteria responsible for the production of nitrates and other substances of nutritive value to plants4 ,the extent of this may be realised from the fact that in a definite weight of soil 7about #a-bhth of an ounce7 the micro-population was calculated to include not only about #a1eej1jjj protozoa1 of which #dcj1jjj were amb 7,fig4 #b71 but also some #f1jjj1jjj1jjj bacteria4 ,observations showed that a single bacteria-destroying amba required about #djj organisms for its nourishment1 so that the amb1 to say nothing of the other protozoa1 present in the weight of soil above-mentioned1 would be capable of destroying about #agb1jjj1jjj of the bacterial population4 ,since the partial sterilisation of soil by steam results in an increase of fertility1 it is thought1 on account of the sterilisation destroying the protozoa1 being more susceptible1 and not the bacteria1 that protozoa inhibit the activities of the bacteria to such an extent as to reduce the fertility of the soil2 but this is a subject as yet open to argument4 ,apart from the bacteria-destroying protozoa1 there are other forms that are thought to have something to do with the decomposition of organic substances4 ,the fungi1 alg and bacteria are amongst the lowest forms of plant life1 and hold somewhat the same position in the plant kingdom as the protozoa do among animals2 they are1 especially the fungi and bacteria1 of primary importance in the maintenance of soil fertility4 ,the role of alg lies mainly in increasing the organic content of the soil1 and they are invaluable in developing favourable conditions for the establishment of vegetation on purely mineral soils4 ,the fungi and bacteria are responsible for setting up the intricate reactions involved in the decomposition of organic matter1 the bacteria being concerned in practically all of the chemical processes going on in the soil4 ,both fungi and bacteria are of two kinds3 those that bring about decomposition1 and those that live in a reciprocal relationship with plants upon the roots of the latter4 ,such relationship1 which benefits both organisms and plants1 is called symbiosis1 the fungi being known as mycorrhiza1 while the bacteria form nodules on the roots of such plants as the legumes4 ,,chapter ,,iii4 ,structure of ,insects4 ,although insects present a great variety of forms1 they nevertheless agree in general features2 thus by studying the structure of some generalised species1 which will give a broad idea of the main characteristics1 one is enabled to recognise different structural modifications assumed by various species4 ,for this purpose a weta1 grasshopper1 or cockroach may be taken as a type4 ,just as in the case of the crayfish1 so the body of an insect is completely covered and protected by a continuous 8shell10 very solid in some insects1 more or less pliable in others1 but even in the most delicate forms tending to become rigid and brittle after death4 ,this shell acts as a skeleton and as a very effective armour-plating1 protecting and supporting the soft body within4 ,unlike the shell of the crayfish1 which is mainly calcareous1 that of insects consists of a horny substance called chitin1 secreted by the underlying skin1 and constitutes what is known as a cuticle4 ,it is due to this horny cuticle or shell that the form and colour of most insects are preserved after death1 though the enclosed body tissues decay unless preserved in some suitable medium4 ,the cuticle1 though forming a complete covering1 does not enclose the body in an inflexible shell2 flexibility is allowed by the cuticle being formed of a segmented series of strongly-chitinised sections alternating with skin-like1 feebly-chitinised1 and very elastic sections2 this arrangement gives freedom of movement to the enclosed body1 as is readily seen in the movements of a caterpillar4 ,there are three distinctly separated divisions of the insect body--head1 thorax1 and abdomen--each consisting of a varying number of segments 7,fig4 #c74 ,the head segments are so closely fused as to be practically untraceable1 the cuticle forming a rigid capsule2 the thorax1 to which the head is attached1 carries the wings 7when present7 and the legs1 and consists of three segments2 posterior to the thorax is the abdomen1 comprised of several segments1 which show the typical segmentation of insects better than any other part of the body4 ,the head capsule is more or less freely movable on the thorax1 and bears certain sensory organs1 together with the mouth appendages4 ,the sensory organs are the eyes and the feelers1 or antenn4 ,on each side is a compound eye of varying size1 according to the insect2 each eye consists of a variable number 7from a comparative few to several thousand7 of microscopic1 hexagonal lenses1 each of which records a separate image4 ,between the compound eyes1 on top of the head1 are three simple eyes in some insects1 but in others one or all of these may be absent4 ,between the compound eyes on the front aspect of the head is a pair of feelers1 or antenn2 they consist of a variable number of joints1 are freely movable and highly sensory1 thread-like or hair-like1 short1 or longer even than the whole body1 and may be bare or clothed to a varying degree with hair or bristles4 ,on the antenn are the organs of touch1 smell1 and sometimes hearing4 ,illustration3 ,,fig4 #c4 ,when the head of a weta1 grasshopper1 or cockroach is removed from the body and boiled for a few minutes in a #aj per cent4 solution of caustic potash1 and then washed in water in order to remove the muscles and other tissues1 a large opening will be seen on the posterior surface where the head was attached to the thorax2 also1 if the mouth appendages are pulled apart1 they will be seen to surround another opening on the lower aspect of the head capsule1 marking the position of the mouth4 ,the digestive canal passes from the mouth through the posterior opening into the thorax4 ,the mouth appendages are as follows 7,fig4 #c73--,suspended from the fore aspect of the mouth opening is a more or less conspicuous movable flap1 which forms the upper lip1 while from the posterior aspect of the same opening is another suspended appendage forming the lower lip2 this latter appendage is really a complicated one1 and bears a pair of short1 jointed appendages--the palps--which are sensory organs1 while on its inner surface--i4e41 within the mouth--is a swollen area or tongue1 an organ very greatly modified in certain insects4 ,between the upper and lower lips1 and suspended from both sides of the mouth opening1 is a pair of true jaws immediately behind the upper lip1 followed by a pair of accessory jaws immediately before the lower lip2 these jaws do not move up and down1 but have a side-wise action1 closing and opening like scissor blades4 ,while the true jaws are each of one piece1 the accessory jaws consist of several parts1 and each bears in addition a jointed palp1 as in the case of the lower lip4 ,the upper and lower lips serve to hold the food in the mouth1 the true jaws nibble or tear off portions of the food and masticate it 7if the term can be used71 while the accessory jaws1 aided by the lower lip1 manipulate the food during the process of feeding4 ,the comparatively simple arrangement of mouth parts found in the weta1 grasshopper1 and cockroach1 as described above1 is characteristic of all insects that gnaw or chew their food--e4g41 earwigs1 beetles and their larv or grubs1 the caterpillars of moths1 and so on4 ,there is1 however1 a vast number of insects that has developed more or less complex variations of this generalised pattern1 according to the manner of feeding4 ,the mouth parts of the worker honey-bee1 for example1 have the jaws adapted for eating pollen and moulding wax for the comb2 the accessory jaws1 however1 are lengthened1 though their palps are reduced to mere vestiges in contrast with the elongated palps of the lower lip2 the most remarkable modification is that of the greatly elongated tongue1 with its spoon-like tip adapted for reaching nectar of flowers having deep-seated nectaries4 ,for the same purpose1 the mouth parts are modified in a moth 7,fig4 #c7 to form a long proboscis1 which lies curled up in a spiral beneath the head when not in use2 in this case the proboscis is the modified accessory jaws1 the remaining mouth parts1 with the exception of the well-developed palps of the lower lip1 being greatly reduced4 ,in a blood-sucking insect1 such as the female mosquito1 all the mouth parts are well developed1 but are very delicate and greatly lengthened and suited for piercing the skin4 ,the greatest modification is found in the blow-fly proboscis1 which is a soft1 sucking tube1 with no outward resemblance to the generalised plan1 except for the palps of the accessory jaws4 ,the mouth parts of insects 7e4g41 aphids7 which feed on the nutrient sap of plants1 just in the same way as mosquitoes do on blood1 are modified for puncturing the tissues of plants2 in such insects the upper lip is short1 and both pairs of palps are atrophied1 but the jaws and accessory jaws are greatly lengthened in the form of bristle-like stylets1 which lie in a groove along the equally lengthened lower lip 7,fig4 #c74 ,the manner in which insects feed is of great importance in controlling them with insecticides1 and the two types to bear in mind are those that chew their food and those that suck the sap of plants1 reached by puncturing the tissues4 ,as already stated1 the thorax consists of the three segments immediately behind the head1 and carries the organs of locomotion2 its three segments are distinct1 and may be referred to1 respectively1 as the fore1 middle1 and hind thorax4 ,the cuticle of each thoracic segment consists of a number of chitinised plates connected by membranous areas2 these plates are arranged in three series--the back or dorsal2 the lower or ventral1 forming the sternum2 and the lateral1 or side-pieces1 connecting the dorsal and ventral ones4 ,at the lower surface of each thoracic segment is attached a pair of legs1 the members of each pair being separated by the sternum of the segment to which they belong4 ,the presence of three pairs of legs is a character by which insects can be distinguished from all other animals2 indeed1 on account of this feature1 insects are sometimes called the hexapods1 or six-legged animals4 ,each leg is covered by a continuation of the body cuticle1 and is five-jointed2 the first two joints at the attachment to the body are small2 the next two are long1 and form the greater part of the limb2 while the fifth1 or foot1 consists of a varying number of small joints1 the terminal one bearing a pair of claws4 ,in the typical winged insects there are two pairs of wings3 one pair attached to the middle thorax1 and the other to the hind thorax2 owing to the development of muscles controlling flight1 the middle and hind thorax of winged insects are usually better developed than the fore thorax2 this is especially noticeable in the thorax of two-winged flies 7daddy-long-legs and blow-flies71 where the hind wings are reduced to vestiges1 the power of flight being thus confined to the middle thorax1 which forms by far the greater portion of the whole thorax4 ,each wing1 arising from the junction of the dorsal and lateral thoracic plates1 is a bag-like extension of the cuticle1 flattened leaf-like1 so as to form a double flexible membrane4 ,the wing membrane is supported by several ribs or veins1 which may be very numerous 7grasshopper7 or few 7aphid71 while the fore edge1 where it cuts the air in flight1 is bordered by a stouter vein1 ensuring rigidity4 ,the fore and hind wings of some insects work independently1 but in agreement of movement1 while in others the fore and hind wings of each side are coupled along their adjoining margins1 giving greater rigidity during flight4 ,the abdomen of insects consists of a varying number of visible segments2 each segment is covered by an upper and lower chitinous plate connected by membrane1 there being no side plates as are found in the thorax4 ,there are no organs of locomotion 7except in a very few cases71 the only appendages being those connected with reproduction2 the latter are well developed in the female weta1 where the egg-laying apparatus1 or ovipositor1 projects blade-like from the apex of the abdomen4 ,in very many insects1 however1 the external reproductive organs are not readily seen without special study4 ,all insects1 from the largest to the most minute1 contain internally a well-formed heart and a digestive1 reproductive1 respiratory1 and nervous system 7,fig4 #c71 while the spaces surrounding these organs are1 for the most part1 packed with a complex system of muscles4 ,the heart is a delicate tube lying along the middle of the back or dorsal surface of the body1 immediately under the skin1 and extends almost from one end of the insect to the other2 in an almost similar position1 close to the lower or ventral surface of the body1 the nervous system is situated1 and consists of a chain of nerve centres1 or ganglia1 connected by a double nerve cord1 the most anterior of these ganglia being in the head and forming the brain1 the following three lying in the thorax1 one to each segment1 while the remainder are confined to the abdomen1 one ganglion to each segment1 as in the thorax4 ,in many insects the number of nerve centres is reduced1 owing to the fusion of two or more4 ,the reproductive organs are located in the abdomen4 ,the digestive system consists of a tube 7,fig4 #c71 with its appendages1 opening at the mouth and at the posterior end of the body2 this alimentary canal may be straight and simple1 or convoluted and complex1 according to the insect and the nature of its food4 ,respiration in insects is carried on by means of a system of air tubes 7,fig4 #c71 which branch and re-branch to form an intricate system of delicate tubular airways1 carrying the atmosphere to all tissues of the body2 the main air tubes open at the surface by a series of breathing pores normally arranged along each side of the body1 except on the head2 these pores are best seen on a caterpillar or on the abdomen of adult insects4 ,,chapter ,,iv4 ,life ,histories of ,insects4 ,no doubt owing to the endless assortment of sizes1 from mere specks to giants of a few inches1 a widespread idea has arisen1 particularly in regard to such insects as have a general resemblance to one another1 that the smaller individuals are the younger stages of the larger4 ,though gradation in size may be a sign of successive ages in certain insects1 the presence of functioning wings denotes that growth has ceased2 in the case of wingless insects1 the characters of maturity may be less conspicuous4 ,although there may be at times a fairly wide range in size among fully-grown individuals of the one species1 such variation is not due to age1 but to certain factors influencing the insect during growth1 such as the abundance or scarcity of food supply1 and favourable or unfavourable climatic conditions4 ,on the other hand1 the sex to which an individual belongs is often responsible for difference in size1 males very frequently being smaller than females4 ,size1 therefore1 is by no means a sign of age1 and the smaller winged insects must not be regarded as the young of the larger ones1 no matter how close is the resemblance4 ,insects1 with the exception of certain species giving birth to living young1 are reproduced from eggs laid by the females2 with few exceptions1 the latter take no further interest in the eggs beyond placing them in surroundings offering the most favourable conditions for their well-being1 and a sufficient food supply for the forthcoming young2 each egg is protected by a delicate shell1 through which the young insect makes its way on hatching4 ,on emerging from the egg1 the young insect commences to feed and grow in size1 until very soon a stage is reached when the cuticle or shell becomes too small for the enclosed insect2 a fluid then collects between the cuticle and the underlying skin1 and a new and more roomy cuticle is secreted by the latter2 on this process being completed1 the old chitinous covering splits1 and the insect withdraws itself4 ,this moulting takes place several times1 until the body is fully grown1 when the cuticle formed at the last moult is retained by the now adult insect for the rest of its life4 ,the different stages through which an insect passes from egg to adult constitute its life history1 or life cycle1 and the relation of the latter to the seasons1 its seasonal history4 ,according to the species1 a full twelve months or even more may be necessary for the complete life cycle1 or the cycle may be repeated several times within the year2 when the cycle occupies twelve months1 the insect is single-brooded2 but two1 three1 or four-brooded1 etc41 when the cycle is repeated two1 three1 or four times1 respectively1 in the year4 ,climatic and food-supply conditions have a distinct influence on the number of broods1 the one species in many cases being single-brooded in colder1 and two or three-brooded in warmer climates4 ,during the winter1 when the temperature is low enough1 insects are more or less dormant in some stage of their life cycle2 such a state is the period of hibernation4 ,illustration3 ,,figure #d4 #a1 ,silverfish4 #b1 ,earwig2 a1 young larva2 b-d1 later stages2 e1 adult4 #c1 ,cicada2 f1 young larva2 g1 resting stage prior to emergence of adult2 h1 adult4 #d1 ,thrips2 i and j1 larvae2 k1 first stage pupa2 l1 second stage pupa2 m1 adult4 #e1 ,aphis-lion2 n1 larva2 o1 pupa2 p1 adult4 #f1 ,moth2 q1 egg2 r-t1 larvae2 u1 pupa2 v1 adult4 #g1 ,house-fly2 w1 egg2 x-z1 larvae2 aa1 puparium2 bb1 adult4 ,,note3 ,developing wings shown in black4 ,all insects do not follow the same method of development from egg to adult1 and the adaptations of structure and habit are many and varied as well as simple and complex4 ,species having a complex development1 during which they pass through stages1 each differing in form from its predecessor1 undergo what is known as a metamorphosis2 contrasted with such insects are those developing in a simple manner without pronounced differences in the form of successive stages1 the young resembling the adult in most features except size and maturity--these insects are without a metamorphosis4 ,intermediate between these two extremes are other insects with a partial metamorphosis4 ,a consideration of the life cycle of some common insects will serve to illustrate the principles of development discussed above4 ,firstly1 will be taken examples of complex development or complete metamorphosis2 secondly1 examples of simple development or absence of metamorphosis1 followed by a review of species having a partial metamorphosis1 thus linking the first two types4 ,a convenient type of insect undergoing a complete metamorphosis is any common moth 7,fig4 #d72 one of the most suitable1 most easily obtained in all stages and commonest in any part of the country from spring to autumn1 is the magpie moth 7,nyctemera annulata7 and its caterpillar1 the 8woolly bear40 ,the moth1 unlike most of its kind1 is a day-flying species1 and is very conspicuous owing to its black colour relieved by white wing spots1 and orange-yellow bands on the abdomen2 the equally conspicuous caterpillar1 feeding on groundsel1 ragwort and cineraria1 is black1 with a very hairy body marked with narrow brick-red lines4 ,the eggs are laid in clusters by the female moth on the under side of the leaves of the caterpillars' food-plant2 at first the eggs are of a pale green colour1 but assume a darker yellowish tint within a few hours1 and finally a leaden colour some time later4 ,these colour changes are due to the developing embryo1 and just before the young insect 7the caterpillar in this case7 hatches1 its outline as it lies curled within the egg is easily seen through the transparent egg-shell2 near the top of the egg is a black spot marking the position of the caterpillar's head1 while the numerous delicate black lines below the egg surface are the black hairs with which the caterpillar is clothed4 ,according to temperature and humidity1 the incubation period--that is1 the period between egg-laying and the hatching of the young caterpillar--varies from eight days to three weeks4 ,the process of hatching occupies about two hours1 the young insect using its jaws to eat an exit hole through the egg4 ,the caterpillar stage--indeed1 the first stage of all insects--is known as the larva4 ,at first the larva of the magpie moth1 measuring about one-sixteenth of an inch long1 is pale yellow in colour1 except for the black head and hairs clothing the body2 very soon1 however1 the body becomes characteristically black1 and develops the reddish lines4 ,during growth the larva feeds continuously day and night1 undergoing from five to ten moults before becoming fully grown4 ,during a moult the cuticle of the head is cast separately from that of the body4 ,the body of the larva is worm-like1 not only in general form1 but also in its segmented appearance2 it is1 however1 a very different animal from a worm4 ,the larva has a distinct head1 a pair of eyes1 and short antenn1 and a set of mouth parts1 similar to those of the weta or grasshopper1 well adapted for devouring foliage2 the first three segments behind the head correspond to the thorax of the moth1 and each bears a pair of short feet2 the remaining segments are those of the abdomen1 and have no true feet1 but six pairs of sucker-like appendages called pro-legs4 ,the number of pro-legs varies from four to six pairs1 according to the species of moth1 and are found only on the larva4 ,the time occupied by larval development of the magpie moth varies from forty to eighty days in summer and autumn2 but if winter intervenes1 causing the larv to hibernate before completing their development1 the larval period may be as long as two hundred and forty-eight days2 normally this insect hibernates in the larval state1 completing its development during the following spring4 ,throughout winter the larv hibernate singly or in colonies under loose bark1 in leaf axils1 or any suitable crevice4 ,the fully-grown larva measures about one and a-half inches long4 ,prior to the final moult it ceases to feed1 and wanders in search of a suitable place in which to undergo the next transformation1 usually among stones1 rubbish1 or under loose bark1 etc4 ,there it spins a white silken cocoon1 among the strands of which are entangled the long black body hairs2 herein the larva undergoes the final moult1 the cast cuticle being easily seen at one end inside the cocoon4 ,the insect1 however1 has now assumed a form quite different from that of the larva2 this form is the chrysalis or pupa1 and as such is incapable of locomotion and feeding4 ,the pupa measures about three-quarters of an inch long1 is yellowish at first1 but soon becomes black with yellow markings1 while the form of the future moth 7head1 antenn1 thorax1 legs1 wings and abdomen7 can be traced on the pupal cuticle4 ,after from about two to five weeks1 the pupa opens by a cross-shaped slit on the back just behind the head1 and the moth draws itself out4 ,at first the moth is comparatively helpless after having been confined within the limited space of the pupal cuticle2 soon1 however1 the body hardens1 the wings smooth out1 and the insect is ready for flight4 ,metamorphosis is carried to a much higher state of perfection in the case of such insects as blowflies and houseflies 7,fig4 #d74 ,the larva1 or maggot1 is without any external sign of head and legs1 though these1 together with the wings of the future fly1 develop from rudiments within the body of the maggot4 ,at the final moult the larval cuticle is not discarded1 as in the case of the moth1 but hardens to form a case--the puparium--within which the pupa lies4 ,the life-cycle of the magpie moth is illustrative of the principles of metamorphosis characterising the development of a great many insects1 such as all moths and butterflies1 beetles1 flies1 bees and wasps1 etc42 but1 although the general characters of the larva1 pupa1 and adult moth are common1 with but slight variation1 to corresponding stages of moths and butterflies as a whole1 these stages in other insects1 though readily recognised1 have their own characteristics4 ,outstanding features in a life-cycle involving metamorphosis are that growth takes place only in the larval state1 and that the insect parades through life in different guises--egg1 larva1 pupa1 and adult--each with its own peculiarity of habit and form1 although the adult and pupa resemble one another much more than do the adult and larva2 but no matter how dissimilar the larva1 pupa1 and adult may outwardly seem1 structures common to them all may be traced throughout4 ,make1 for example1 a comparative study of the larva1 pupa1 and moth of the magpie moth2 the head1 thorax1 and abdomen can be seen in each stage1 while counterparts of the larval antenn1 eyes1 mouth-parts and feet persist in the moth1 though more or less profoundly modified during pupal transformation4 ,although there are no external signs of wings in the larva1 these appendages are developing1 nevertheless1 in concealed 8pockets0 within the larval thorax1 and1 at the time of pupal formation1 become extruded and lie ensheathed with the legs and antenn in the pupal cuticle along the sides of the pupal body4 ,apart from these changes1 the larval mouth parts undergo a most profound metamorphosis2 apparently1 though there is no similarity between the long 8tongue0 or proboscis of the moth and the jaws and accessory jaws of the caterpillar1 the proboscis1 adapted for sipping the nectar of flowers1 is nothing but the accessory jaws of the leaf-chewing larva greatly elongated2 with the exception of the palps of the accessory jaws1 the other larval mouth parts are either absent in the moth or reduced to vestiges4 ,in the case of insects that develop without a metamorphosis1 the life-cycle is one of comparative simplicity4 ,an example of such an insect is the so-called 8silverfish0 7,lepisma saccharina71 common in dwellings1 especially in damp places1 dark and dusty corners1 flour and sugar bins1 while not uncommonly it causes some considerable damage by devouring the paste and glaze from wallpapers and the binding and leaves of books4 ,the silverfish 7,fig4 #d71 wingless throughout life1 measures about one-quarter of an inch long when full grown2 it is silver-white in colour1 due to a clothing of glistening scales that rub off as a silky powder when the insect is handled4 ,it glides rapidly about1 especially after dark1 and is one of the most primitive insects1 there being minute leg-like processes attached in pairs to the under side of the abdomen2 the normal thoracic legs are well developed4 ,the body is wedge-shaped1 tapering to the posterior end1 from which three tail-like appendages project1 while anteriorly a pair of long1 delicate antenn arises from the head4 ,all stages of the silverfish1 from the minute1 freshly-hatched individuals to fully-grown ones1 may be found in the one place1 the smaller ones being immature developing stages4 ,in the case of another species allied to the common silverfish1 the female lays from six to ten eggs at one time in sheltered crevices1 and the young hatch forty-five to sixty days later1 when the temperature ranges from #fe degrees to #fh degrees ,fahrenheit4 ,unlike the moth larva1 that of the silverfish throughout its growth resembles the adult both in habit and form1 the only marked differences being that of size and the absence of the abdominal leg-like appendages4 ,during growth several moults take place1 and at the final one the adult appears with all its characteristics4 ,some species take two years to reach maturity4 ,in this type of insect there is1 therefore1 no pupal or resting stage1 and the larval habits and food are the same as those of the adult insect1 while there is but little difference in structure throughout all the stages4 ,there are many winged insects 7e4g41 cockroaches1 crickets and earwigs7 that show a slight advance toward a metamorphosis4 ,though their larv differ from the adults principally in the absence of wings1 there are stages between the younger larv and the adults in which the wing rudiments appear4 ,these rudiments first appear after one of the moults as small bud-like structures on each side of the thorax 7earwig1 ,fig4 #d71 becoming larger after each succeeding moult1 when the developing wings may be seen enclosed in a sheath of the cuticle2 at the final moult the wings1 no longer enclosed in their coverings1 straighten out and become functional4 ,a very pronounced difference is here noted between the wing development of such insects and that of a moth1 in that the wing rudiments of the former develop externally and those of the latter internally4 ,a decided advance toward a metamorphosis is exhibited by insects known as thrips 7,fig4 #d74 ,though readily overlooked on account of their minute size 7one-twenty-fourth of an inch and less71 they are nevertheless conspicuous on green foliage and white flowers owing to their blackish or yellowish colour4 ,thrips1 when magnified1 are easily recognised by their peculiar wings2 each is feather-like1 being formed of a narrow rib-like membrane clothed along the margins with long and delicate stiff hairs4 ,thrips' eggs are laid upon the plant surface or within the tissues1 according to the species1 and are very minute 7about one-twenty-third of an inch long74 ,the larv puncture the plant tissues and feed upon the juices just as do the parents1 which they resemble in general form1 except that there are no wings and the antenn are very short and the eyes small4 ,there are two or three larval moults1 after which the insect is more like the adult1 though still resembling the larva4 ,it now differs from the latter1 however1 in the antenn being considerably shortened1 and in the appearance of a pair of finger-like processes on each side of the body attached to the thorax and lying along the sides of the abdomen2 these processes are the sheaths enclosing the wing rudiments of the future adult4 ,the insect again moults1 changing to a form resembling the preceding stage in many respects1 but differing in the wing sheaths being much longer1 and in having the antenn1 enclosed in sheaths of cuticle1 turned back over the head4 ,although during these two stages the insect is capable of moving about1 it is nevertheless sluggish and does not feed2 from this second semi-quiescent stage the adult emerges4 ,in the thrip's cycle1 therefore1 although the habits of the larva and adult are similar1 the presence of the two intermediate semi-quiescent stages1 during which feeding ceases1 shows a decided advance toward a true metamorphosis and represents a pupal stage4 ,in the case of those insects not involved by a metamorphosis1 as discussed above1 the structure and habit of both adult and the immature stages differ but little1 the development of wings being the principal change1 except in the case of the thrips1 where there is a definite tendency toward a pupa4 ,however1 passing on to a consideration of the common cicada 7wrongly called a locust71 a change in both structure and habit occurs during the life-cycle1 the immature stages being adapted to a subterranean life1 while the winged adult frequents the foliage of trees2 all stages agree1 however1 in puncturing plant tissues with their proboscis and sucking up the nutrient juices from the roots by the larva and from the stems and leaves by the adult4 ,the female cicada 7,fig4 #d7 lays its eggs in colonies beneath the young bark of trees and shrubs2 the larv1 on hatching1 drop to the ground1 into which they burrow2 the antenn and soft body are comparatively long1 while the fore legs are greatly modified for grasping plant roots and as digging tools4 ,after a number of moults1 the body shortens1 the antenn come to resemble those of the adult1 and the rudiments of the wings appear4 ,growth and the activities of the developing insect continue until finally the larva constructs an earthen underground chamber1 in which it lies torpid until ready to undergo the final moult2 in this inactive state1 though still resembling the later larval stages1 the insect corresponds to the pupa of the moth4 ,for the final moult the pupa leaves the ground1 crawls up some support 7a tree trunk or post71 where the winged adult emerges1 leaving the empty pupal husk attached to the support4 ,besides the change in habit and the possession of functional wings1 the adult cicada differs in many structural features from the immature stages4 ,outstanding differences are the normal fore legs1 the development of a 8voice-box0 in the male1 and an ovipositor in the female4 ,an insect that shows some linkage between those having a true metamorphosis and those having a partial metamorphosis is the aphis-lion 7,micromus tasmani71 though undergoing a true metamorphosis itself4 ,the larv are predaceous and feed upon aphids 7,fig4 #d74 ,its larva1 pupa1 and adult are distinct forms1 as in the moth1 but the larva is not of the specialised caterpillar or grub type1 rather resembling in general appearance the silverfish1 or the type of young larva peculiar to such insects as the earwig or thrips before the wing rudiments develop4 ,furthermore1 the pupa1 though one in the strict sense1 is capable of great freedom of movement1 its head1 mouth-parts1 antenn1 legs and wings1 ensheathed by the cuticle1 being freely movable1 and not rigidly attached to the body4 ,a review of the early larval stages of the earwig1 thrips and cicada1 prior to wing development1 and of the aphis-lion larva1 shows a conformity to a generalised type exemplified by the primitive silverfish4 ,on the other hand1 the moth caterpillar exhibits another larval type more highly specialised1 though still retaining a modified semblance to the silverfish type1 while specialisation is carried to the highest degree in the blowfly maggot1 where all outward sign of the primitive larval type is lost4 ,regarding the pup1 there are three types2 the most simple is the free pupa1 like that of the aphis-lion1 and some moths1 beetles1 etc41 where the appendages are freely movable4 ,the most complex is the pupa of the blowfly1 enclosed in its puparium1 while intermediate between these two extremes are many moth pup that have the appendages firmly attached to the body1 but nevertheless visible4 ,,chapter ,v4 ,sucking ,insects4 ,the term 8sucking insect0 is applied to all insects that have the mouth parts modified as delicate stylets1 by means of which the plant tissues are punctured and the nutrient sap sucked up4 ,not only may such insects weaken the infested plants1 but they also cause the destruction of chlorophyll1 interfere with the normal functioning of the stomata1 and have a toxic effect upon the tissues2 further1 many serious plant diseases are carried and spread by sucking insects1 whilst the punctures made when feeding may allow the entry of disease spores4 ,among sap-sucking insects are scale insects1 mealy-bugs1 aphids1 leaf-hoppers1 white-flies1 thrips1 etc4 ,infestation by most of these insects 7especially in the case of scale insects1 mealy-bugs1 and aphids7 is very often detected by the sticky nature and blackened appearance of the plants2 this is due to the fact that the insects excrete a sweet1 sticky substance known as 8honey-dew10 which collects on the foliage and branches1 whilst upon it grows a black1 sooty mould4 ,scale ,insects and ,mealy-bugs4 ,scale insects and mealy-bugs1 collectively known as coccids1 are of very great economic importance on account1 not only of their widespread depredations upon plants1 few being free from infestation1 but also of the commercial value of some species--e4g41 in the production of lac1 cochineal1 ,chinese wax1 etc42 it is with the injurious forms that the ,new ,zealand horticulturist is concerned4 ,the term 8scale insects0 is derived from the appearance of many of the species that are protected by a scale-like covering1 which forms a conspicuous scaly incrustation when a plant is heavily infested4 ,of the several kinds of insects injurious to vegetation1 the coccids as a family are undoubtedly of major importance1 because they infest not one group1 or allied group1 of plants1 as do so many other injurious insects1 but an extensive range of widely different plants4 ,some coccids are much more injurious than others1 the ,san ,jos ,scale1 for example1 having a very virulent toxic influence1 while the ,greedy ,scale may cause but little damage1 even when the plant is completely encrusted by it2 further1 some plants may be more susceptible to injury than others by the same species of coccid4 ,coccids1 as a whole1 are highly specialised insects1 and among themselves exhibit a great variety of forms4 ,throughout the group the sexes differ to a marked degree4 ,the adult males1 which vary but little in all the coccids1 are usually minute1 and1 with few exceptions1 two-winged 7,fig4 #e72 none has mouth parts1 these appendages having become atrophied during metamorphosis1 which is complete1 while many have one or more hair-like tail appendages4 ,on the other hand1 females are never winged2 some are comparatively large2 all have well-developed mouth parts throughout life1 and undergo incomplete metamorphosis1 while in many forms the legs and antenn are lost before maturity4 ,in all cases coccids secrete a protective covering1 which assumes different forms2 this fact1 together with the chief methods of female development1 is utilised for the purpose of this work to arrange the coccids under three main types as follows3-- #a4 ,,less ,,specialised ,,forms4--,examples are the mealy-bugs and cottony-cushion scale1 which belong to the more generalised or least specialised representatives4 ,the protective body covering is in the form of a powdery or mealy secretion2 the legs and antenn are retained throughout life1 and the insect remains freely mobile4 ,a typical-form life-cycle may be studied in that of the cottony-cushion scale 7,figs4 #e and #f;a74 ,during development the female insect passes through three larval stages2 each of these stages is1 on the whole1 similar1 except for size and minor structural changes1 and the white powdery secretion that covers the reddish body of the adult4 #b4 ,,intermediate ,,forms4--,an example is the olive scale 7,fig4 #e74 ,in such forms there is a tendency to specialisation1 owing to more or less sedentary habits in later life1 and protection is afforded by a thickening and toughening of the cuticle on the upper surface of the body4 ,unlike the cottony-cushion scale1 the female olive scale passes through two larval stages2 the minute first stage larva is active and very flat2 it soon settles upon a leaf and commences to feed1 when it becomes much flatter and a little larger2 the second stage differs from the first in size and in the development of a dorsal longitudinal ridge1 which eventually forms the cross-bar of the two transverse ridges that are characteristic of the third or adult stage1 when the insect swells and assumes the shape of the mature form4 ,after settling in the first larval stage1 the insect becomes very sluggish1 and does not move1 except to migrate1 as most do1 from the leaves to the twigs1 there to take up a permanent position4 ,the legs and antenn are retained throughout life1 but in the adult are functionless1 being folded against the body2 in some species of intermediate forms the appendages become atrophied during development4 ,in the olive scale1 and related forms1 the toughened cuticle not only serves as a protection to the insect1 but also as a receptacle for the eggs 7,fig4 #e72 as these are laid and increase in numbers1 the body of the parent diminishes and is crowded against the dome-shaped cuticle4 #c4 ,,specialised ,,forms4--,the apple mussel-scale 7,figs4 #e and #g1 ,nos4 #b and #f7 is a representative of this group1 the members of which are markedly specialised1 the legs and antenn of the adult female becoming completely atrophied during development1 and the shape of the body profoundly altered2 protection is afforded by a scale-like covering not attached to the body4 ,in the mussel-scale development there are two larval stages3 the first1 like all coccids1 has the legs and antenn well developed and is active4 ,illustration3 ,,fig4 #e4--;,,illustrations ,,of ,,different ,,types ,,of ,,scale-,,insect ,,life-,,histories4 ,on settling to feed1 this first larva commences to produce a covering of white threads that mat together to form the first scale2 the second stage larva presents profound changes in the absence of legs and antenn1 while the body has become pear-shaped1 the head1 thorax and abdomen seeming as one2 a second more waxy scale is now formed4 ,after a second moult1 the adult appears1 and resembles the second stage larva in form2 the adult constructs a third scale1 very much larger than the earlier ones1 to which it remains attached by its anterior end4 ,though many of the specialised coccids form elongate scales1 as in the case of the mussel-scale1 numerous others construct circular scales1 as does the ,san ,jos 7,fig4 #e72 in the latter1 the second and third scales are constructed round the first1 so that the first and second appear as pimple-like structures in the centre1 or slightly to one side of the completed covering4 ,as with the olive scale1 the covering of the specialised forms serves as a receptacle for the eggs 7,fig4 #e74 ,some of the more important coccids occurring in ,new ,zealand will now be discussed4 ,,cottony ,,cushion ,,scale7,icerya purchasi74--,this insect 7,fig4 #f;a7 is a native of ,australia1 but has now become established in many other countries1 including ,new ,zealand4 ,for a time it was a serious pest of citrus1 until the introduction and establishment of its natural enemy1 the ladybird beetle 7,novius cardinalis74 ,the adult female is more or less oval1 and covered with a yellowish powder1 partly concealing the reddish-brown ground colour and dark spots along the sides of the body2 the legs are black4 ,a characteristic feature is the white corrugated egg-sac attached to the end of the body 7,fig4 #e74 ,as the eggs are laid1 this sac increases in size1 until it may measure fully #b-a_/b times the length of the parent1 which becomes tilted up4 ,the eggs are orange-yellow1 and as many as #hjj may be produced by a single female4 ,the eggs hatch in about a fortnight during summer1 and the period of development to the adult ranges from three to five months4 ,the larv most frequently congregate along the mid-ribs of leaves1 and as development advances they usually migrate to the twigs and branches4 ,there are two generations each year4 ,a considerable variety of plants is attacked by this insect1 chief among which are citrus1 acacia1 gorse1 wattle1 and ,douglas fir4 ,control is effected by the agency of the ladybird1 but epidemics sometimes occur with which the beetle cannot immediately cope2 in such a case fumigation in the glass-house1 or spraying with red oil in the open1 should be resorted to4 ,,mealy ,,bugs4--,mealy bugs are characterised in the female by the nature of the waxy protective secretion which forms a powdery meal-like covering over the body1 but is developed as a fringe of leg-like processes at the side 7,fig4 #f;b72 these processes at the posterior end of the insect may be prolonged as longer or shorter tail-like appendages in some species1 or they may be no longer than those fringing the body margins in others4 ,immediately after each moult the larv are devoid of mealy covering and lateral processes1 which are secreted anew each time the cuticle is shed4 ,in a mealy bug colony are numerous small1 narrow cocoons1 in each of which a developing male insect lies4 ,most mealy bugs produce eggs1 which are laid in a spacious1 cottony sac secreted at the posterior end of the female2 the female insects1 egg sacs1 and male cocoons together form characteristic woolly masses on infested plants4 ,the injury caused by mealy bugs may be considerable1 not only through the drainage of plant sap1 but also owing to the production of honey-dew and its consequent sooty mould4 ,all parts of plants are subject to mealy bug attack1 and the insects are frequently attended by ants4 ,illustration3 ,,fig4 #f4 7a7 ,cottony cushion scale4 7b7 ,mealy bug4 7c7 ,the black olive scale4 7d7 ,gum tree scale3 ,on right1 females on twig2 upper left1 male scales2 lower left1 the ladybird beetle2 centre1 scales destroyed by beetle4 7e7 ,hemispherical scale4 7f7 ,fruit lecanium scale4 ,photographs by ,w4 ,c4 ,davies1 ,cawthron ,institute4 ,mealy bugs are controlled to a great extent by natural enemies1 among which are the ,tasmanian lace wing 7,micromus tasmani7 and the ,cryptolmus ladybird 7,cryptolmus montrouzieri71 but the influence of these is insufficient for commercial purposes4 ,attempts are now being made at the ,cawthron ,institute1 ,nelson1 to establish other parasites recently imported from ,california4 ,control under glass is effective by means of fumigation1 but in the open is a more difficult matter1 though red oil and lime-sulphur give some satisfactory results1 together with the practice of removing rough bark on trees where the insects hibernate4 ,in ,new ,zealand are several species of mealy bugs1 of which the following are of interest to the horticulturist3-- ,,long-,,tailed ,,mealy ,,bug7,pseudococcus adonidum74--,this species is readily recognised by the long tail-like appendages of the female4 ,it is widely distributed and commonly met with under glass1 where it infests almost any plant2 in the warmer and moister districts of the ,dominion it occurs out of doors4 ,its list of host plants is a lengthy one1 and includes grape vine1 passion vine1 wistaria1 fig1 oleander1 ,phormium1 cineraria1 begonia1 apple1 plum1 palms1 ferns1 etc4 ,considerable injury may be caused by the insect when it occurs in dense masses on the under side of foliage and upon young1 succulent growth4 ,no eggs are produced by this insect1 the young being born alive2 the production of young lasts for a period of from two to three weeks at the rate of about twelve each day2 the time taken to reach maturity varies considerably1 according to climatic conditions1 the range being from one to three months4 ,there are comparatively few generations each year out of doors1 but under glass there may be several4 ,,citrophilus ,,mealy ,,bug7,pseudococcus gahani74--,in ,new ,zealand this species is met with on grape vines and begonia in glass-houses1 where it becomes epidemic if left uncontrolled2 out of doors it infests apple and potato1 and no doubt other plants are attacked4 ,it is characterised by the mealy covering being coarse and distributed unevenly over the body1 while the marginal fringe is short1 the processes being comparatively thick1 particularly the tail-like ones1 which are much shorter than the body1 though conspicuous4 ,egg-laying covers a period of about two weeks1 from #cid to #fgi eggs being deposited by each female2 development to the adult is completed in about six weeks1 though this will vary according to the conditions4 ,in ,california four generations in the year have been noted4 ,,apple ,,mealy ,,bugs7,pseudococcus maritimus and ,p4 comstocki74--,both these species occur upon apple1 pear and potato in ,new ,zealand1 the former species originating in ,america1 and the latter in ,japan2 the injury to the host itself is not severe1 but the presence of these insects on the fruit is responsible for apples and pears being rejected for export4 ,both species are very similar in appearance1 and are of the short-tailed type2 they differ from the citrophilus mealy bug in having the mealy covering evenly distributed over the body1 while the marginal fringe is delicate and thread-like4 ,the eggs hatch in from one to three weeks1 and the larv migrate freely1 the insects reaching maturity one or two months later1 according to climatic conditions4 ,in the open the winter is passed in the egg stage1 but under glass or in mild climates activity among the different stages occurs throughout the year4 ,apart from apple and pear1 these insects have been recorded from many plants3 ,baker's mealy bug 7maritimus7 on lemon1 orange1 walnut1 willow1 elder1 ivy1 iris2 and ,comstock's mealy bug on citrus1 elder1 euonymus1 gooseberry1 grape1 horse chestnut1 hydrangea1 mulberry1 peach1 persimmon1 plum1 poplar1 wistaria4 ,,the ,,gum ,,scale7,eriococcus coriaceus74--,this is one of the most spectacularly destructive scale insects now established in the ,dominion4 ,it is a native of ,australia1 and its normal hosts are the several species of eucalyptus1 though it is sometimes found on apricot and willow4 ,a characteristic feature of infected eucalyptus is their blackened appearance1 due to sooty mould growing on the copious honey-dew secreted by the scale4 ,on an infested twig or branch1 the insects may be so closely packed as to conceal the bark 7,fig4 #f1 d72 each female lies in a pear-shaped sac of felted secretion1 reddish-brown1 tawny1 or sometimes white in colour1 measuring about three-twenty-fifths of an inch long1 and having a circular aperture at one end4 ,the enclosed insect is somewhat flattened1 oval1 and blood-red in colour2 when crushed1 it leaves a reddish and sticky smear4 ,the developing males are to be found forming white patches of innumerable individuals on the tree trunks under the loose bark 7,fig4 #f1 d74 ,the female is viviparous2 during spring1 mid-summer and autumn immense numbers of young are produced1 which escape through the opening at one end of the female sac1 and are carried long distances by the wind4 ,these young insects first settle on the eucalypt leaves1 whence they migrate1 the females to take up their final position on the twigs and smaller branches1 and the males to continue their development on the trunk of the tree4 ,the gum tree scale occurs throughout the districts east of the ,southern ,alps and in the vicinity of ,nelson1 in the ,south ,island1 and over the southern half of the ,north ,island2 it is1 however1 spreading rapidly northward4 ,this pest is held in control by means of the black-ladybird beetle 7,rhizobius ventralis7--,fig4 #f1 d--which was imported for the purpose from ,australia2 birds such as the tui1 wax-eye1 fantail1 blackbird and thrush congregate on infested trees and eat the insect4 ,,olive ,,scale7,saissetia ole74--,this insect has a world-wide distribution1 and is one of the most important pests of citrus in ,new ,zealand1 although it occurs on a wide range of plants2 in all cases it infests the fruit1 bark1 and the under side of leaves4 ,the host plants include citrus1 apple1 pear1 apricot1 plum1 almond1 fig1 grape-vine1 wistaria1 pepper tree1 oleander1 holly1 laurel1 palms1 camellia1 rose4 ,the injury caused by the insect is not so much on account of its weakening influence upon the infested plants as of the fact that it copiously secretes honey-dew1 so that black mould develops to a marked degree1 necessitating the washing of herbaceous plants and fruit4 ,the adult female 7,fig4 #f1 c7 is hemispherical1 and measures about one-fifth of an inch in diameter1 a characteristic distinguishing feature being the three ridges forming the letter ,h on its upper surface 7,fig4 #e74 ,according to age1 the colour varies from brownish or greyish to jet black1 the insect being conspicuous against the lighter background of bark or leaf2 the small1 immature individuals are light brown or yellowish1 and almost flat4 ,in ,new ,zealand the winter is passed in both egg and larval stages1 though a few adults may be found at that time2 on turning over what appears to be an adult1 it will usually be found that the female has died and her place taken by numerous eggs 7,fig4 #e74 ,the average number of eggs produced has been estimated at from #a1ejj to #b1jjj per female2 at first the eggs are white1 but prior to hatching they turn a deep orange-red4 ,development is slow1 the adult state being reached about three months after time of hatching2 egg laying commences about five weeks after maturity1 and continues for a period of about six weeks4 ,there is only one generation each year1 and all stages may be met with on the one plant2 the greatest activity occurs during the summer months4 ,an important natural enemy of this scale is the steel-blue ladybird beetle 7,orcus chalybus71 introduced from ,australia4 ,,hemispherical ,,scale7,saissetia hemispherica74--,this world-wide species is commonly met with in ,new ,zealand1 and1 though not a serious pest1 has a wide range of host plants1 both in the open and under glass2 some of the commoner hosts are citrus1 fig1 oleander1 palms1 japonica1 camellia1 asparagus1 and orchids4 ,both leaves and stems are infested by the insect1 which resembles the olive scale 7,fig4 #f1 e72 from the latter it may be distinguished by its light brown colour and smooth surface1 there being no ridges2 the longest diameter of the adult female is one-seventh of an inch4 ,between #ejj and #a1jjj eggs are laid by each female1 and the life-cycle is completed in about six months2 the young insects settle along the main leaf-veins4 ,,turtle ,,scale7,coccus hesperidum74--,this widely-distributed insect1 though common in hot-houses and out of doors in the warmer parts of the ,dominion1 is not especially injurious1 except for the copious honey-dew secreted and the consequent sooty mould2 it occurs on holly1 ivy1 camellia1 citrus1 laurel1 myrtle1 oleander1 and japonica4 ,the insect infests leaves and stems1 and is especially abundant on succulent growth4 ,the adult female is rather reddish-brown in colour1 dome-shaped1 but with the margins flattened on the host plant2 on each side the margin is notched by a shallow depression1 and there is a deeper one at one end2 over the surface is a reticulation of ridges1 resembling the pattern on the back of a turtle2 fully-developed individuals measure from one-sixth to one-eighth inch in diameter4 ,this species is viviparous1 and development to the adult occupies about nine weeks2 there may be three or four generations each year4 ,,fruit ,,lecanium ,,scale7,eulecanium corni74--,this ,european insect is common throughout the ,dominion1 where occasionally it becomes epidemic and causes some temporary damage2 with it are associated honey-dew and sooty mould4 ,among the plants infested are apricot1 peach1 nectarine1 plum1 pear1 grape-vine1 wistaria1 raspberry1 mulberry1 blackberry1 gooseberry1 black currant1 ferns4 ,leaves and bark are infested1 and a narrow twig may be partly encircled by the margins of the scale4 ,the adult female 7,fig4 #f;f7 is oval and dome-shaped1 some individuals measuring one-sixth of an inch in length2 the surface is smooth1 except toward the margins1 parallel to which are some wrinkles4 ,the general colour is dark brown1 but just prior to egg-laying there are numerous transverse and longitudinal markings of a lighter colour over the surface4 ,the winter is passed in the egg stage or as partly-grown young4 ,another1 but larger1 species1 closely resembling the preceding1 and found on grape-vines1 wistaria1 eleagnus1 etc41 is ,eulecanium berberidis4 ,it is reddish-brown in colour1 and measures up to one-third of an inch in length4 ,,golden ,,oak ,,scale7,asterolecanium variolosum74--,this insect is very common upon ,english oak trees in parts of ,new ,zealand4 ,in many cases so badly are the trees infested1 that they become sickly in appearance1 and at times the greater part1 or even the whole1 of the tree is killed through the agency of the pest4 ,the individual scale 7,fig4 #g1 #a7 is more or less circular1 and about one-sixteenth of an inch in diameter2 it is of a greenish-yellow colour1 with a narrow paler circumference1 though some1 with the exception of the rim1 are partly or wholly brownish4 ,each scale forms and lies in a depression of the bark4 ,the insect is viviparous4 ,a minute parasite1 ,habrolepis dalmanni 7note the exit holes made by the parasite during emergence from some of the scales shown in the photograph7 has recently been established as a means of control and is proving effective4 ,,camellia ,,scale7,pulvinaria camelicola74--,this ,european scale sometimes heavily infests camellias and euonymus in ,new ,zealand1 but is not a very serious pest1 though more so in glass-houses than out of doors4 ,after the female has produced her eggs1 she drops off the plant1 so that1 though the latter shows evidence of injury1 there may be no sign of the insect4 ,the adult female is oval and about one-third of an inch at its longest length2 in shape it resembles a rather flattened turtle scale1 but when laying eggs the body shrivels and numerous transverse wrinkles develop1 although the margins of the scale remain smooth4 ,there is at least one generation each year1 and in warmer parts probably a second1 which may reach maturity before winter or not till the following spring4 ,the eggs are laid in an elongate1 white1 cottony sac secreted at one end of the female2 this sac is sometimes as much as four to five times the length of the insect4 ,the eggs continue to hatch over a period of from four to six weeks1 and the larv rapidly spread2 the latter settle along the leaf mid-rib1 margin1 or lower surface4 ,,apple ,,mussel ,,scale7,lepidosaphes ulmi74--,the apple mussel scale is now established throughout the temperate regions of the world4 ,it is commonly met with on apple1 but has a long list of host plants1 among which are pear1 hawthorn1 willow1 poplar1 gooseberry1 and currant4 ,the insect 7,fig4 #g1 ,nos4 #b and #f7 forms incrustations on bark and fruit1 and is commonly met with at the stalk end of the apple2 the individual scale is chocolate-brown in colour1 is shaped like the shell of the salt water mussel--hence the name 8mussel scale0--and when full grown measures one-eighth of an inch long4 ,a single female is capable of laying up to #gjj eggs1 in which stage the winter is passed4 ,the eggs hatch in the spring1 and the young insects swarm over the host plant in search of a suitable place to settle4 ,a continuous warm spell of weather in the spring will allow all the eggs to hatch almost at one time1 but alternating cold spells will retard development1 so that emergences take place over a longer period4 ,after emerging from the egg until maturity1 when egg-laying again takes place1 a period of three months elapses2 the insect is a slow breeder1 and produces only one brood a year in colder climates1 but is two-brooded in warm districts1 such as ,auckland4 ,a small hymenopterous parasite 7,aphelinus mytilaspidis71 less than one-twenty-fifth of an inch long1 attacks this scale1 but does not serve as an efficient control2 individual scales that have been killed by the parasite show a small hole through which the adult parasite has emerged4 ,the most effective control is secured by treating infested trees with red oil or lime-sulphur during winter4 ,,cabbage ,,tree ,,scales7,leucaspis cordylinidis and ,leucaspis stricta74--,cabbage trees and also ,new ,zealand flax often have the leaves encrusted by the white masses of these two native scales4 ,the adult female of one species 7,l4 cordylinidis7 measures one-eighth of an inch long1 is very narrow and straight as a rule1 and white in colour1 except for the yellow anterior end 7,fig4 #g1 #d74 ,the other species 7,l4 stricta7 resembles the former1 except that the adult is one-eleventh of an inch long1 and has the anterior half blackish4 ,in the case of ornamental cabbage trees and flax1 control can be effected by removing all dead and scale-infested leaves1 thus allowing access to sunlight4 ,,san ,,jos ,,scale7,aspidiotus perniciosus74--,of all scale insects of major importance1 the ,san ,jos 7,fig4 #g1 #e7 is outstanding1 in that it is one of the insects most destructive to deciduous trees and shrubs1 a considerable number of which are liable to attack4 ,it is of ,chinese origin1 and first came into prominence when it became established at ,san ,jos1 in ,california1 hence its name4 ,owing to its small size1 it is easily overlooked1 except when epidemic1 and is readily transported upon plants from one country to another4 ,the list of plants attacked is a long one1 but the following may be mentioned3--,acacia1 hawthorn1 quince1 privet1 poplar1 almond1 apricot1 cherry1 plum1 peach1 pear1 apple1 gooseberry1 currant1 roses1 willow1 ash1 elm4 ,the female ,san ,jos scale is circular in outline1 having a diameter of about one-twenty-fifth of an inch2 in profile it has the form of a flat cone with a crater-like depression at the apex1 in the centre of which lies a minute pimple-like prominence2 the immature scales are smaller and whitish in colour1 while the male scale is elongate-oval in outline1 with the crater-like depression toward one end4 ,the individual scales are greyish and are readily overlooked1 but when well established upon a tree they form an incrustation giving a characteristic dull silver-grey appearance to the tree2 bark1 fruit and leaves are infested4 ,a characteristic feature of ,san ,jos scale infection is the discolouration of the plant tissues immediately surrounding each insect1 which turn a distinct red or purple1 giving at once an indication that this scale is present4 ,the winter is passed by the insect in almost a mature state2 on the advent of spring1 development to maturity continues1 when1 after mating1 the females give birth to living young over a period of several weeks4 ,the young reach maturity and commence to reproduce five to six weeks from birth1 there being several generations in the course of a season4 ,the average number of young produced by each female has been found to be about #djj4 ,illustration3 ,,fig4 #g4 7#a7 ,golden ,oak ,scale2 7#b7 ,apple ,mussel ,scale2 7#c7 ,black ,scale2 7#d7 ,cabbage ,tree ,scale2 7#e7 ,san ,jos ,scale2 7#f7 ,apple ,mussel ,scale2 7#g7 ,oleander ,scale2 7#h7 and 7#i7 ,rose ,scale4 ,photographs by ,w4 ,c4 ,davies1 ,cawthron ,institute4 ,natural enemies in ,new ,zealand are two species of hymenopterous parasites1 ,aphelinus fuscipennis and ,a4 mytilaspidis1 the latter also attacking the apple mussel scale4 ,ladybird beetles also feed upon the insect4 ,control requires close attention1 and can be effected by the application of lime-sulphur in the dormant season1 when it is essential to apply a strong wash to kill off as many scales as possible before reproduction commences in the spring4 ,at bud movement further applications are necessary to destroy the young insects4 ,,red ,,orange ,,scale7,chrysomphalus aurantii74--,the red orange scale is distributed throughout the world1 and is especially abundant in tropical and sub-tropical regions1 the most southern limit being ,new ,zealand4 ,as a major pest it is peculiar to citrus1 but infests to a minor extent other plants--e4g41 plum1 apple1 pear1 quince1 grape1 fig1 euonymus and rose4 ,so far it has been found only on citrus in ,new ,zealand1 it being well established in the ,auckland province1 and also in the ,south ,island on ,banks ,peninsula4 ,it is very often found on imported oranges and lemons4 ,this scale is a circular one1 with a central pimple-like prominence1 as in the case of the ,san ,jos1 but is flatter1 about half as large again1 and is of a characteristic reddish colour4 ,the damage done to citrus trees by this insect is of a serious nature1 as the entire tree or part of it may be killed in severe infestations4 ,a characteristic feature of this species is that no honey-dew is secreted1 and hence there is a total absence of sooty mould on infested trees4 ,like the ,san ,jos scale1 the red scale is viviparous1 and over-winters as partially mature adults1 completing development in early spring1 when the young insects make their appearance4 ,an average of about #ee young is produced by each female1 and development to maturity takes from two or two and a-half months2 about one month later young are produced1 and their production continues over a period of one or two months2 climatic conditions1 however1 have a direct influence on development4 ,an important natural enemy is the steel blue ladybird 7,orcus chalybus71 imported from ,australia2 but the most efficient control is cyanide fumigation1 or spraying with red oil or lime-sulphur4 ,,the ,,black ,,scale7,chrysomphalus rossi74--,foliage of palms1 oleander and citrus is often infested by this reddish-black to black circular scale 7,fig4 #g1 #c72 it is almost flat1 with a central whitish spot1 and measures up to one-tenth of an inch in diameter2 when many individuals are crowded together1 their outline becomes irregular4 ,this species is not especially injurious1 though common4 ,,oleander ,,scale7,aspidiotus heder74--,this cosmopolitan insect occurs on orchids1 oleander1 ivy1 camellia1 palms1 citrus1 coprosma1 and karaka1 infesting stems1 leaves and fruit4 ,in the case of citrus1 this insect delays colouring of the fruit1 which becomes blotched with yellow or green4 ,the insect may be so numerous1 that it completely covers the whole plant1 giving to the latter a white appearance2 this is due to the preponderance of white male scales1 the female being slightly yellow1 with a purplish tint4 ,the female scale is almost circular 7,fig4 #g1 #g71 having a diameter of from one-twenty-fifth of an inch to two-twenty-fifths of an inch1 and is rather flat2 the male is more oval and of the same size1 and in both cases there is a central orange-yellow spot4 ,the eggs are comparatively large1 and hatch soon after being deposited4 ,the insect reaches maturity in from four to six weeks4 ,,greedy ,,scale7,aspidiotus rapax74--,this ,european insect is now widespread1 and in ,new ,zealand is common on apple1 pear1 quince1 and wattle2 it has a wide range of hosts4 ,the adult female scale is convex and of a general grey colour1 though sometimes yellowish4 ,the winter is passed in all stages of development4 ,,rose ,,scale7,aulacaspis ros74--,this is a very common insect1 forming white incrustations on the bark of roses1 briar1 raspberry1 loganberry1 blackberry1 and sometimes pear4 ,the adult female 7,fig4 #g1 #h71 which is from one-twelfth of an inch to one-eighth of an inch in diameter1 is rather thin and flat1 circular or oval in outline1 but irregular when crowded2 the general colour is white or slightly yellowish4 ,the male 7,fig4 #g1 #i7 differs1 in being elongated and narrow4 ,this insect can withstand severe winters1 and is to be controlled by the use of red oil4 ,,chapter ,,vi4 ,sucking ,insects--7,concluded74 ,plant ,lice1 or ,aphides4 ,the small1 soft-bodied plant-lice1 or aphides1 usually found forming dense colonies on all sorts of plants1 are pests well known to every gardener2 they attack plants by inserting into the tissues their delicate piercing mouth-parts1 and drain the nutrient sap 7,fig4 #h1 #a;g74 ,all parts of a plant may be infested1 and the insects1 owing to their ability to reproduce abundantly and rapidly1 may destroy the plant1 or at least injure it by stunting its growth1 curling the leaves1 or deforming the flowers and fruit4 ,in many cases aphides copiously secrete honey-dew1 upon which sooty mould grows1 rendering the plant unsightly2 on this honey-dew ants feed1 and are frequently seen associated with aphides4 ,apart from their direct injurious effects1 aphides are of outstanding importance1 in that they transmit some of the most serious plant diseases4 ,of all the species occurring in ,new ,zealand1 only one species is supposed to be a native4 ,most aphides live exposed upon the host plant 7e4g41 ,rose ,aphis71 but some 7e4g41 ,woolly ,aphis7 secrete a protective covering1 while others cause a malformation of the plant tissues which form a partial protection as a semi-gall 7e4g41 ,elm-leaf ,aphis71 or a complete protection as a true gall 7e4g41 ,leaf-petiole ,gall-aphis of ,poplar74 ,aphides present certain variations in structure1 and1 generally speaking1 the one species presents four or five types 7,fig4 #h1 #a73 the asexual 7parthenogenetic7 wingless and winged females that give birth to living young 7viviparous7 in the absence of males1 and the sexual forms1 both males and females1 the latter producing eggs 7oviparous74 ,the best character by which the ,new ,zealand aphides are to be recognised is to be found in the pair of longer or shorter horn-like processes1 or 8cornicles10 projecting from the upper surface of the abdomen2 in some species1 however1 the 8cornicles0 are reduced and inconspicuous 7e4g41 ,woolly ,aphis71 or altogether absent 7e4g41 ,grape ,phylloxera74 ,the 8cornicles0 are frequently called 8honey-tubes10 since for many years it was thought that they secreted the honey-dew2 it has been shown1 however1 that the honey-dew is secreted from the rectum1 and that the function of the 8cornicles0 is to secrete a waxy protective substance1 which may take the form of a powder or woolly threads4 ,the wings1 when present1 are membranous1 the front pair being much larger than the hind ones1 and when not in use usually close roof-like over the body4 ,illustration3 ,,fig4 #h4 7#a7 ,life ,history of an ,aphis3 ,a1 egg2 ,b1 ,c1 and ,f1 wingless females2 ,d1 winged female2 ,e1 male2 ,g1 section of head and plant tissue to show method of attack4 7#b7 ,life ,history of a ,leaf-,hopper3 ,h1 eggs under bark of twig2 ,i1 first stage hopper2 ,j1 later stage hopper with developing wings2 ,k1 adult from above2 ,l1 adult from side4 7#c7 ,life ,history of a ,white ,fly3 ,m1 egg2 ,n1 first stage larva2 ,o1 pupal stage under scale covering2 ,p1 adult4 7#d7 ,an adult ,thrips4 ,in their life-histories and habits aphides present many variations1 sometimes of considerable complexity1 but fundamentally the processes are as follows3--,eggs are laid on the host plant during the autumn1 and give rise to wingless females in the spring2 these females 7being asexual or parthenogenetic1 since they reproduce without being fertilised7 are viviparous1 producing living forms similar to themselves4 ,some of these forms remain wingless1 while others may develop wings1 upon which a wider dispersal of the species depends1 but in both cases such females are asexual and viviparous4 ,several such generations may develop until the autumn1 when males and females appear1 the latter being oviparous1 producing the over-wintering eggs when fertilised by the males4 ,very often1 however1 the life-cycle is considerably complicated by the winged forms flying to other host plants and establishing there colonies differing in many respects from the parent stock2 from these secondary hosts there is a return migration to the original species of plant4 ,again1 the migrations may be restricted to different parts of the same plant1 from the leaves or branches to the roots1 for example4 ,most aphides are readily controlled by means of insecticides1 such as nicotine-sulphate1 or kerosene-emulsion4 ,they are also very often held in check by natural enemies1 such as aphis-lions1 hover-flies1 ladybirds1 and numerous forms of hymenoptera4 ,the following species are some of the commoner aphides met with in ,new ,zealand3-- ,,black ,,peach--,,aphis7,aphis persic-niger74--,from early spring1 even before the foliage develops1 this aphis may be found heavily infesting the young1 succulent shoots of peach2 it also occurs on cherry1 plum and nectarine4 ,the adult insects are black and the immature stages pale reddish-brown1 dull brown1 or lemon-yellow4 ,during the winter the insect lies underground about the roots of the host plant1 and thence migrates to the young growth in spring4 ,at first only wingless forms are seen1 but as the season advances the winged migratory aphides develop2 at that time the foliage is so severely attacked that it becomes crumpled and functionless 7,fig4 #i1 #a71 while the developing fruit is distorted and rendered useless4 ,the heat of the late summer destroys the aphides still on the foliage1 but sufficient numbers descend underground for protection1 where they live over winter4 ,,green ,,peach--,,aphis7,rhophalosiphum persic74--,this aphid occurs on a wide range of plants1 including the peach1 and1 as a rule1 is most abundant during summer and autumn2 as the name implies1 the general colour is green1 though some individuals are reddish or brownish-yellow2 the wingless forms have black-tipped 8cornicles10 and on the abdomen of the winged insects are dark markings4 ,,black ,,cherry--,,aphis ,,or ,,fly7,myzus cerasi74--,this aphid has now a world-wide distribution4 ,in ,new ,zealand it has been found on cherry and plum1 though in other countries its hosts include peaches1 red and black currants1 and cruciferous plants1 such as common mustard1 shepherd's purse1 etc4 ,this species exudes copious honey-dew1 upon which sooty mould develops1 thus rendering fruit unfit for use4 ,the principal injury1 however1 is due to the destruction of shoots and leaves1 the latter frequently curling up when the insect clusters in dense colonies upon the infested plant4 ,the complete life-cycle has not been followed under ,new ,zealand conditions1 but the shiny black eggs occur on the bark and buds of cherry trees during the winter4 ,in spring the eggs hatch1 and the insects1 rapidly reproducing1 attack the young shoots and leaves4 ,observers in other countries have noted that there is a summer migration of winged females to cruciferous plants1 where colonies are established1 and whence there is a return migration during the autumn to the original host4 ,the wingless females are black1 with part of the legs yellow1 while the young individuals are pale in colour2 the winged females have a green abdomen1 from which arise the black 8honey-tubes40 ,since all the over-wintering eggs have hatched by the time the buds open1 the insect can be then controlled by applications of nicotine-sulphate4 ,illustration3 ,,fig4 #i4 7#a7 ,peach leaves attacked by ,black ,peach aphis4 7#b7 ,colony of ,cabbage aphis on leaf4 7#c7 ,stem of insignis pine attacked by ,chermes4 7#d7 ,grape ,phylloxera and galls on vine roots4 7#e7 ,grape ,phylloxera galls on vine leaf4 7#f7 ,woolly aphis on apple twig4 7#g7 ,galls of ,poplar aphis4 7,figs4 #a1 #b and #f by ,w4 ,c4 ,davies2 ,fig4 #d4 after ,u4,s4 ,dept4 ,agric42 ,fig4 #e4 after ,n4,z4 ,dept4 ,agric47 ,,cabbage ,,aphis7,brevicoryne brassic74--,the cabbage aphis1 or cabbage green fly1 is widely distributed throughout the world1 and has become a serious pest in ,new ,zealand1 causing considerable damage to cruciferous crops2 it infests rape1 turnip1 cabbage1 ,brussels sprouts1 cauliflower1 as well as related weeds1 such as wild mustard1 shepherd's purse and watercress4 ,most damage is done during dry seasons1 when the plants succumb more readily to attack2 if the insects are numerous1 they cause the leaves to curl1 and give a greyish appearance to infested plants1 which may become flaccid and sticky from the copious honey-dew of the insect4 ,the wingless forms are bluish in colour and coated with a greyish powder1 but the winged females have the head and thorax black and the abdomen greenish 7,fig4 #i1 #b74 ,in ,new ,zealand all stages may be found throughout the year on winter crucifers or on weeds1 though reproduction is retarded during the winter2 in the spring the winged females fly to young crops4 ,in very cold climates eggs are laid in the autumn1 and these survive the winter4 ,the cabbage aphis is attacked by a number of parasites1 and usually the brownish empty shells of a large number that have been destroyed by a small parasite are to be found at any time2 other important enemies are the hover-flies1 the eleven-spotted ladybird beetle1 and the ,tasmanian aphis-lion4 ,the insect can be controlled by spraying with nicotine-sulphate to which soap has been added4 ,,pine ,,tree ,,chermes7,chermes pini74--,this is a widely-distributed species1 occurring upon both ,austrian and insignis pine in ,new ,zealand4 ,the insect lives in colonies upon the cones1 twigs and branches1 as well as around the bases of the needles2 each aphis exudes a woolly covering1 which forms conspicuous white masses when the trees are heavily infested 7,fig4 #i1 #c74 ,young trees seem to be the more subject to infestation1 from which they may recover as they grow1 but some damage is caused by the insect by a weakening of the trees1 especially where grown in unsuitable localities4 ,it is frequently noticed that individual trees in a plantation are heavily infested1 while adjacent trees of the same species are not4 ,the wingless form of the insect1 covered by its mat of white threads1 is brownish in colour and ornamented with numerous dark spots2 there are no 8honey-tubes0 on the abdomen4 ,the life-cycle of this insect becomes complicated1 when it develops on two types of conifers2 in the latter case the primary host is a species of spruce upon which the insect forms galls1 and the secondary host may be larch1 ,douglas fir or pine1 upon which gall formation is unusual4 ,so far as is known1 only the pine-infesting form of the aphis occurs in ,new ,zealand4 ,,grape ,,phylloxera7,phylloxera vastatrix74--,this destructive aphis1 sometimes called the grape louse1 is a native of ,north ,america1 where it normally infests grape vines4 ,it was accidentally introduced into the grape-growing districts of ,france1 where it became very destructive4 ,it later made its appearance in ,new ,zealand4 ,the insect infests both the leaves and roots of grape vines1 the root-feeding stages being the most destructive1 in consequence of which vines are now grown on resistant root stocks4 ,the leaf-infesting stages of the insect cause pocket-like galls to form1 which open on the upper surface of the leaf by a narrow aperture concealed under a tuft of delicate hairs 7,fig4 #i1 #e74 ,in each gall the aphid matures and deposits several hundreds of eggs1 from which wingless females hatch2 these wander to other leaves1 and each insect forms a new gall for itself4 ,several generations develop thus1 but later many of the offspring migrate underground and join the root-infesting colonies4 ,the irritation set up by the latter causes yellow flabby nodules to develop on the roots 7,fig4 #i1 #d74 ,these nodules1 or galls1 later decay4 ,the root-feeding aphides are wingless1 and reproduce by means of eggs for several generations4 ,although they may go on developing thus for many years1 it usually happens that1 toward autumn1 some of the insects transform to winged females1 which fly to other vines or are carried thence by the wind4 ,there each female feeds on the lower leaf surface1 and deposits two kinds of eggs1 some larger and some smaller2 from the larger develop wingless females1 and from the smaller wingless males1 which are unable to feed4 ,after fertilisation1 each of these females deposits a single egg upon the older bark of the vine2 such eggs do not hatch until the spring1 when they give rise to the wingless females that start the galls on the leaves4 ,control depends on the use of phylloxera-resistant stocks1 since it is from the root colonies of the aphis that the foliage is re-infested in the spring4 ,an important feature is to prevent the scion from sending down roots where the union of the scion and root stock is close to the soil2 if such scion roots form1 they should be cut away and the soil removed from the union4 ,,rose ,,aphis7,macrosiphum ros74--,the rose aphis is perhaps one of the best-known insects of the garden1 mainly owing to its prevalence upon the young growth of all kinds of roses2 it sometimes occurs on apple1 tomato and rhododendrons4 ,in a colony some of the insects are pink1 and others bright green1 though in the winged forms the head1 antenn1 thorax1 a row of spots on each side of the abdomen1 and the 8honey-tubes0 are black2 in both winged and wingless forms the eyes are red4 ,in the case of severe infestations1 plant growth is retarded and the leaves and flowers become distorted4 ,control can be effected by applications of nicotine-sulphate1 kerosene1 or soap solution4 ,,apple ,,woolly ,,aphis7,eriosoma lanigerum74--,although frequently called 8,american ,blight10 the apple woolly aphis is probably a native of ,europe4 ,it occurs throughout ,new ,zealand1 and was a very serious pest until controlled by the ,aphelinus parasite4 ,the presence of this insect is made apparent by the characteristic white woolly patches 7,fig4 #i1 #f7 which appear upon the apple trees1 due to the woolly material secreted by the aphid4 ,another feature is that the part of the tree attacked1 even after the insects have disappeared1 is disfigured by gnarled swellings1 due to abnormal thickening of the inner bark4 ,this species also infests apple tree roots1 which become similarly malformed4 ,however1 root infestation has been overcome by using root stocks1 such as ,northern ,spy1 that are immune4 ,the individuals comprising a colony of woolly aphis are variously coloured1 yellow1 green and red predominating2 a considerable amount of honey-dew is secreted4 ,this species has been found to migrate to the foliage of the elm and mountain ash1 but in ,new ,zealand the elm-infesting form has not been found to occur4 ,the insect becomes active in spring1 and rapidly increases until the autumn4 ,under favourable climatic conditions1 winged females develop and produce males and females1 the latter laying eggs4 ,the woolly aphis is preyed upon by the nine-spotted ladybird1 but1 as this beetle is itself the victim of another insect1 its utility is greatly minimised4 ,the most important check to the aphis is the ,aphelinus parasite 7,aphelinus mali71 the influence of which has been spectacular under ,new ,zealand conditions4 ,,plum ,,aphis7,rhophalosiphum nymph74--,this insect is sometimes very common during spring upon the shoots and leaves of plum in ,new ,zealand2 in other countries it has been found to migrate to and infest the flowers and leaves of water lilies4 ,the insects assume various shades of green1 the winged females having the head1 thorax1 and legs blackish2 the 8honey-tubes0 vary in colour1 and may be reddish1 blackish or yellowish4 ,,poplar ,,gall ,,aphis7,pemphigus pupuli-transversus74--,upon the leaf stems of poplar trees in many parts of ,new ,zealand sac-like growths 7,fig4 #i1 #g71 measuring anything from half an inch to one inch in length1 may be found4 ,these are the galls formed by the ,north ,american poplar gall aphis4 ,in each gall are colonies of the aphis surrounded by a mass of flocculent secretion4 ,the walls of the gall are thick and tough1 with the outer surface wrinkled1 while at the end1 toward one side1 is a slit-like1 or sometimes circular1 opening surrounded by a thickened rim1 presenting much the same appearance as the mouth of a sack gathered together and tied4 ,for the most part1 these insects are wingless females only1 but during the summer1 and particularly toward the end of autumn1 winged females develop and migrate to cruciferous plants1 such as cabbage1 rape1 mustard and turnips1 or weeds allied to these cultivated forms1 upon the roots of which they establish colonies surrounded by a woolly secretion4 ,in spring a return migration to the poplar takes place1 and galls are again established4 ,leaf-hoppers4 ,leaf-hoppers form a group of small1 narrow-bodied1 sap-sucking insects2 as the name implies1 they infest the foliage of a variety of plants1 and when disturbed have the habit of suddenly leaping or hopping to safety2 the species present in ,new ,zealand are usually of a greenish or yellowish colour4 ,the adult insect is winged 7,fig4 #h1 ,k1 ,l71 and the female lays her eggs in the plant tissues 7,h72 from these eggs the young wingless hoppers 7,i7 hatch and attack the plant2 as they grow1 wings develop 7,j71 but until then the insect depends for locomotion upon its hopping powers4 ,the most outstanding species in ,new ,zealand is the apple leaf-hopper 7,typhlocyba australis74 ,this insect causes considerable damage to apple trees unless controlled1 which can be effected by spraying with nicotine-sulphate against the young insects in the spring4 ,white-flies4 ,white-flies1 or mealy-wings1 are minute sap-sucking insects1 having the body and wings covered with mealy wax4 ,the female 7,fig4 #h1 ,p7 lays her eggs1 frequently in circular batches1 upon foliage1 and the young insects 7,n7 are active1 but settle down and commence feeding soon after hatching4 ,later the insects change to another form 7,o71 without legs and antenn1 and so resemble scale insects to a certain extent2 from the latter1 however1 they may be distinguished by the waxy covering1 bearing spine-like processes1 and by being surrounded by a distinct marginal area4 ,an important species in ,new ,zealand is the greenhouse white-fly 7,trialeurodes vaporariorum71 against which fumigation with calcium cyanide is the best as a check4 ,thrips4 ,the foliage of many plants is sometimes infested by very minute black insects1 known as thrips4 ,a species commonly met with is that found upon ripe peaches4 ,thrips are readily identified by the structure of the wings 7,fig4 #h1 #d71 which are but narrow strips fringed with long1 rigid hairs4 ,these insects1 by puncturing the plant tissues and sucking up the nutrient sap1 very often are responsible for infecting healthy plants with disease1 such as mosaic4 ,according to the species of thrips1 the female lays her eggs either in the plant tissues or upon the surface4 ,the young insects are wingless1 but attack the plant in the same manner as does the adult2 as development proceeds1 the insect transforms to a pupa1 from which the adult ultimately emerges4 ,a characteristic symptom of thrips infestation is a silvering of the foliage1 while the leaves are further rendered unsightly by the minute specks of hardened excreta ejected by the insects4 ,many thrips pass their whole development upon the host plants1 while others pass part of their lives underground4 ,one of the commonest species met with under glass and out of doors is the greenhouse thrips 7,heliothrips hmorrhoidalis74 ,thrips are readily controlled by means of nicotine-sulphate4 ,,chapter ,,vii4 ,leaf-,feeding ,insects4 ,leaf-feeding insects have their mouth-parts developed for the biting off and mastication of their food2 such insects are1 in general1 earwigs1 crickets and grasshoppers1 the caterpillars of moths and butterflies1 beetles and their grubs1 and the grubs of saw-flies4 ,such insects vary1 not only in their period of activity1 some feeding at night1 others during the day1 but also in the manner under which they set about it4 ,many feed exposed upon the surface of the plant1 while others require protection1 such as is afforded by the webbing together of leaves4 ,some feed upon the leaf epidermis only2 some eat holes in the leaf-surface1 or gnaw irregular notches from the leaf-edge2 while the grosser feeders completely devour the whole4 ,earwigs4 ,in many parts of ,new ,zealand the ,european earwig 7,forficula auricularia7 causes considerable damage in gardens1 while in ,central ,otago it sometimes ruins the stone fruits4 ,during the winter this insect lies underground1 where the female will be found with her cluster of eggs4 ,in the spring these eggs hatch1 and the small whitish young earwigs 7,fig4 #d1 #b7 emerge from the ground to feed largely upon the pollen and pistils of flowers4 ,at that time the insects and the injury they do are not very noticeable1 but as the earwigs grow in size they become conspicuous and extend their depredations to the foliage of plants and to fruit4 ,earwigs are nocturnal in their habits1 and during the day take shelter among fallen leaves1 under stones1 sacking1 or boards1 etc41 lying on the ground1 and may even burrow into the soil itself4 ,in the control of the earwig1 a great deal can be done by what may be called clean gardening--that is1 the removal of all places likely to shelter the insect above ground during the day4 ,another important means is systematic trapping1 one of the simplest methods being to place crumpled newspapers on the ground at nightfall1 in which many of the insects will seek shelter1 the papers being collected and burned next day4 ,but the best method is the use of the following poison bait3--,with #ablb4 of bran mix #f quarts of water1 to which has been added #eoz4 of glycerine and #foz4 of sodium fluoride2 to this mash add #dlb4 of treacle1 taking care to thoroughly mix the whole4 ,this bait is spread at nightfall in places frequented by earwigs1 and should be repeated regularly1 especially after wet weather4 ,it is obvious1 if satisfactory results are to be secured1 that there should be a co-operative campaign organised among the residents of an earwig-infected district4 ,crickets and ,grasshoppers4 ,fortunately1 neither crickets nor grasshoppers 7,fig4 #aj1 #a and #b7 are a serious menace to the ,new ,zealand horticulturist1 though at times1 especially in the warmer parts of the country1 crickets may do some extensive damage4 ,the control of these pests is a difficult matter1 since they are mobile insects1 and breed in places outside the boundaries of the horticulturist's activities4 ,some benefits can be secured1 however1 by thorough cultivation1 which breaks up the egg-masses which are placed in the ground4 ,in the case of serious outbreaks1 the use of a poisoned bait would have to be resorted to1 and the following is recommended from the several recipes in use3--,with #belb4 of bran mix #c or #d gallons of water in order to make a thin mash2 to this1 add #b quarts of molasses and #alb4 of ,paris green1 thoroughly mixing the whole4 ,if crickets alone are to be dealt with1 then use a little more of the ,paris green4 ,this mash is spread on the ground invaded by the insects4 ,caterpillars4 ,of the leaf-feeding insects1 the caterpillars of moths are the most commonly met with1 there being a considerable number of destructive species4 ,caterpillars 7,fig4 #aj1 #c7 can be readily distinguished by their structure from the grubs of other insects4 ,they resemble short earthworms in shape1 and in having the body divided into several segments1 of which there are usually thirteen2 but here the resemblance to worms stops4 ,there is a distinct head--the first segment--provided with jaws1 and on the under side of each of the next three segments1 or thorax1 is a pair of short feet4 ,the remaining segments comprise the abdomen1 and possess sucker-like feet1 varying in number according to the kind of caterpillar2 in some forms there may be as many as five pairs of such feet1 in some three pairs1 and in others two1 but in all the pair on the terminal segment persists4 ,many caterpillars are more or less hairy1 and others comparatively nude4 ,the following are amongst the most injurious kinds3-- ,,leaf ,,rollers4--,it is a common sight to see small greenish caterpillars sheltering between two or more leaves of plants that have been tied together by the silken threads spun by the caterpillars2 protected thus1 the insects feed more or less in security4 ,these caterpillars belong to several species of the tortricid moths1 which are themselves comparatively small and drab in colour4 ,of these species1 the most abundant one1 comprising over #hd per cent4 of the leaf-roller population1 is the ,australian apple-leaf roller 7,tortrix postvittana72 the caterpillars of this insect by no means confine their attacks to the apple1 but feed equally well upon pear1 orange1 grape1 rose1 insignis pine1 oak1 pelargoniums1 etc4 ,apart from attacking the foliage1 the caterpillars frequently tie a leaf to the surface of apple and stone fruits1 and feed upon the skin of the latter1 causing a blemish4 ,the apple-leaf roller passes the winter in the caterpillar stage between two leaves4 ,in the spring these caterpillars transform to pup1 which give rise to moths from the end of ,august to about the end of ,october2 there are at least two broods of caterpillars during the year1 but the limits of these broods are not clearly defined4 ,the caterpillars are attacked by several species of parasites4 ,leaf-rollers are easily controlled by the arsenical sprays used against codlin moth1 but these sprays must be continued into the late summer after their need against codlin moth is past4 ,,diamond-,,backed ,,moth7,plutella maculipennis74--,the caterpillars of this moth 7,fig4 #aj1 #d7 are commonly found attacking the leaves of cabbages1 rape and other cruciferous crops and weeds4 ,these caterpillars are small and greenish1 and1 if disturbed1 suddenly drop suspended by a silken thread attached to the plant4 ,the damage they do is very often extensive1 considerable areas of the foliage being devoured4 ,when fully developed1 each caterpillar spins a silken cocoon on the under side of the leaf1 and there transforms to the pup1 from which a moth eventually emerges4 ,the insect is small1 narrow1 and has a light-coloured1 diamond-shaped marking along the back4 ,the moth is nocturnal1 and shelters amongst the denser foliage during the day2 it emerges at night1 and lays its eggs upon the leaves4 ,the life-cycle from eggs to adult occupies some #cf days1 more or less1 according to the season1 and there may be six or seven generations during the year4 ,in control1 an important point to note is that the diamond-backed moth breeds upon cruciferous weeds--watercress1 shepherd's purse1 and hedge-mustard--as well as on the old plants of a crop left in the ground2 it is from such places that infestation of future crops arises1 and the clearing up of such breeding places should be given close attention4 ,under garden conditions1 control can be secured by spraying the plants with arsenate of lead 7to which a spreader must be added in the case of cabbage71 which should be done especially when the plants are young4 ,,kowhai ,,moth7,mecyna maorialis74--,the caterpillar of this native moth sometimes becomes epidemic1 when it does considerable damage to kowhai1 broom1 lupins1 and sometimes clover4 ,the caterpillar1 which measures about an inch when mature1 is of a greenish colour1 having rows of black tubercles with white centres along the sides1 and a double row of white spots along the back2 from the black tubercles black bristle-like hairs arise4 ,the caterpillar spins a silken cocoon1 in which it pupates4 ,the moth is comparatively small1 the fore wings being yellowish-brown with darker markings1 and the hind wings orange-yellow with a blackish border4 ,there are at least two broods of caterpillars annually3 the first in the spring1 and the second during autumn4 ,arsenate of lead will give effective control on garden legumes4 ,,cut-,,worms4--,this term is applied to the caterpillars of a number of night-flying noctuid moths2 these caterpillars are smooth-bodied and rather worm-like1 in some cases measuring from one and a-half to two inches in length when full grown4 ,they feed at night1 and their method of attack is characteristic in that they nip off young plants close to the ground 7,fig4 #aj1 #e71 so that the latter fall over1 when they are devoured by the caterpillars2 this habit has given rise to the name 8cut-worms40 ,during the day the cut-worms are to be found curled up in the ground close to the plants they have been attacking4 ,the moths of these caterpillars are rather stout-bodied1 and measure about three-quarters of an inch long4 ,one of the commonest species is the cosmopolitan greasy-cut-worm 7,agrotis ypsilon74 ,illustration3 ,,fig4 #aj4 7#a7 ,cricket4 7#b7 ,grasshopper4 7#c7 ,caterpillar4 7#d7 ,diamond-backed ,moth--a1 adult moth2 b1 egg2 c1 larva2 d1 pupa4 7#e7 ,cut-worm lying by damaged plant4 7#f7 ,tomato-worm ,caterpillar--a1 adult2 b1 larva4 7#g7 ,cabbage ,white ,butterfly--a1 adult2 b1 egg2 c1 larva2 d1 pupa4 7#h7 ,larva case of ,bag-moth4 ,though cut-worms are active throughout the growing period of plants1 most damage is done to young and tender plants at the time of establishment1 and this is particularly noticeable in the spring4 ,when plants are grown isolated in rows1 and the area is not too large1 complete protection from cut-worms can be secured by enclosing each plant in a tin collar pushed into the ground and projecting a few inches from the surface2 these collars are removed when the plant is well established4 ,in localities where cut-worms are very troublesome it is advisable to reduce their numbers by means of a poison bait made as follows3--#ejlb4 of bran and #alb4 of ,paris green are thoroughly mixed in a dry state2 when this is done1 and just before being used1 the bran is moistened with water1 sweetened with molasses1 until the bait reaches a crumbly1 but not saturated1 condition4 ,this bait may be broadcast over the infected area or laid around each plant as a barrier4 ,this bait must be applied every few days until the plants have reached a stage when they are able to withstand cut-worm attack4 ,a great deal can be done to check cut-worms by removing dense growths of weeds and rough herbage growing in unused parts of the garden2 in such places the insects breed1 and are a source of infestation4 ,another point to consider is that thorough cultivation will destroy many pup that are lying underground1 and which would otherwise give rise to another generation of moths4 8,,army-,,worms40--,these caterpillars are similar in their appearance and general habits to the cut-worms1 but differ in their method of attack4 ,when present in numbers1 they move through a crop--especially cereals--eating as they go1 and leaving nothing but devastation in their wake1 much as does an invading army on the march4 ,they are not of so much interest to the horticulturist as to the farmer4 ,,tomato-,,worm7,heliothis armigera74--,this caterpillar 7,fig4 #aj1 #f7 is one of the most conspicuous caterpillars met with in the garden4 ,its habit of boring into and eating the contents of tomatoes gives it the name of 8tomato-worm40 ,it is a cosmopolitan insect1 and is especially destructive to flower buds and fruit1 a wide range of plants being attacked4 ,the caterpillars vary in colour1 some being greenish and others brownish1 with reddish1 yellowish or white markings4 ,the moth1 which belongs to the noctuid group1 is on the wing both day and night1 mostly during the earlier part of the year2 it is a stoutly-built insect1 measuring somewhat over half-an-inch long2 its colour is a brownish-orange1 with oblique darker bands on the wings4 ,as the insect passes the winter and spring as a pupa in the ground1 thorough cultivation will help to destroy a considerable number4 ,the use of arsenate of lead sprays1 however1 is the most effective control for the caterpillars4 ,,hawk ,,or ,,sphinx ,,moth7,sphinx convolvuli74--,this conspicuous insect and its caterpillars are most abundant in the ,auckland province1 though found as far south as ,christchurch4 ,the caterpillars feed on convolvulus1 but do considerable damage to the foliage of the kumara and sometimes tobacco4 ,the caterpillar is the largest met with in the garden2 it is stout in form1 and measures up to #c-a_/b inches when fully grown4 ,it is to be recognised at once on account of the dark red1 horn-like process arising from the end of the body4 ,the caterpillar may be of two colours--the one green1 with diagonal yellow bars on the sides2 the other1 brownish-yellow1 with dark lines on the back and sides4 ,from about ,february to ,november the insect lies in the ground as a pupa4 ,the latter can be recognised by a curved process arising from the head and lying along the body4 ,the moth flies rapidly during the last and earlier months of the year2 it is a large1 conspicuous insect1 about #a-a_/b inches long1 with greyish-brown mottled wings1 while the abdomen is conspicuously barred with white1 red and brown4 ,arsenate of lead against the young caterpillars during ,november to ,february would act as an efficient control4 ,,cabbage ,,white ,,butterfly7,pieris rap74--,this butterfly 7,fig4 #aj1 #g7 is a recent importation1 having been first noted at ,napier in #aicj4 ,since then it has spread with marvellous rapidity throughout the ,north ,island1 and has appeared in the ,south ,island1 in the vicinity of ,timaru4 ,the caterpillars of this insect are particularly severe in their attacks upon the foliage of cabbages and cauliflowers1 though they also feed upon many other related plants1 such as lettuce and radish1 besides cruciferous weeds4 ,the caterpillars of the white butterfly are not to be confused with those of the diamond-backed moth1 already described4 ,the full-grown white butterfly caterpillar is a conspicuous insect1 and measures up to an inch and a-quarter in length2 it is easily distinguished by its leaf-green colour and velvet-like appearance1 while down the centre of the back is a narrow orange stripe1 and on each side a brownish line formed of little spots4 ,the chrysalis measures about three-quarters of an inch long1 having a pointed process from the head1 and a keel-like ridge on its back1 while the colour varies according to the surroundings with which the chrysalis blends2 it is not protected by a cocoon of silk1 and may be found upon the food plant or any other support near by4 ,the butterfly itself is a very conspicuous insect1 measuring about two inches across the expanded wings4 ,the female is of a yellowish-white colour1 with darker to blackish markings at the fore-angles of the front wings1 while there are two similar spots on the surface of the same wings1 and one on the hind pair4 ,the male is whitish1 with a dull greyish-green or bluish hue1 marked much as the female1 except that there is only a single spot on the surface of each wing4 ,the eggs 7,fig4 #aj1 #g;b7 are bottle-shaped1 and stand erect upon the leaf surface1 where they are laid singly1 and not in batches2 they are visible to the naked eye4 ,the eggs hatch within a week after being laid4 ,there are several generations each year4 ,the cabbage butterfly can be controlled by the use of lead arsenate4 ,it has been found effective when planting out to first dip the seedlings in lead arsenate at the rate of #alb4 in #ej gallons of water1 to which #alb4 of laundry soap is added as a spreader4 ,during the growth of the crop the same strength of arsenate and soap can be applied as a spray4 ,,magpie ,,moth7,nyctemera annulata74--,one of the commonest and most conspicuous day-flying insects of the garden and field is the magpie moth4 ,it is black in colour1 relieved by an orange-banded abdomen and whitish spots on the wings1 two on each of the front wings and one on each hind one4 ,its black1 hairy caterpillars1 commonly called 8woolly bears10 have narrow brick-red lines along the body1 and very often do some considerable damage to cinerarias2 they also attack weeds1 such as ragwort and groundsel4 ,the small globular eggs are laid in clusters on the leaves of the food plant4 ,at first they are pale green1 later becoming dark yellow1 and just before the young caterpillars emerge from them they change to a leaden colour4 ,when fully fed1 the caterpillar seeks a sheltered place 7beneath stones1 under1 bark1 etc471 and there spins a loose cocoon1 in which it transforms to the chrysalis2 the latter becomes blackish or brownish in colour1 with yellow markings4 ,there are several generations during the year4 ,cinerarias can be protected by spraying with lead arsenate1 or1 better1 by removing the caterpillars by hand and destroying them4 ,,cabbage ,,tree ,,moth7,venusia verriculata74--,the foliage of the cabbage tree is frequently holed on the surface and notched along the edges--this is the work of the cabbage tree moth caterpillars4 ,the history of the insect is as follows3--,the nocturnal moth measures about an inch and a-half across the expanded wings1 which are characteristically coloured by alternating chocolate-brown and yellowish-white lines running from wing-tip to wing-tip across the body1 so that the insect merges into the general pattern and colour of a dead leaf1 upon which it usually rests4 ,the eggs are green1 and at first blend with the green leaf1 on which they are often laid in batches2 when on dead leaves they become conspicuous4 ,later the eggs change colour to brown1 and finally red4 ,the caterpillars congregate in the unopened foliage1 and their injury becomes apparent as the leaves open4 ,the larv transform to chrysalids in silken cocoons1 loosely spun in any suitable crevice upon the trees4 ,if it was necessary and practicable to protect ornamental cabbage trees from the attacks of this insect1 it could be done by removing dead leaves from the crown and spraying with arsenate of lead to which laundry soap had been added4 ,,bag ,,moth7ceticus omnivorus74--,this is an insect that never fails to attract attention on account of its cigar-shaped bags 7,fig4 #aj1 #h71 constructed by the larv1 and are to be found attached to a variety of plants1 upon the foliage of which the larv feed1 though they are not serious pests4 ,each caterpillar spins its own tough silken bag1 which it never leaves1 and to the outside of which it frequently attaches fragments of leaves and twigs4 ,though the male is a normal moth1 and flies about 7it is practically black1 and densely haired1 with translucent smoky-black wings having an expanse of about an inch and a-quarter71 the female develops in an abnormal manner1 and assumes a grub-like form1 never leaving the bag woven by its caterpillar4 ,if it should be found necessary1 as sometimes happens1 the only satisfactory way of controlling the bag-moth is to remove by hand and destroy4 ,beetles4 ,unlike the caterpillars of moths1 there are very few beetles in ,new ,zealand that are important leaf-feeders4 ,though few in numbers1 however1 the outstanding ones are very destructive4 ,the beetles themselves1 as well as their larv1 according to the species1 may attack foliage1 but in other cases it is only the beetles that feed on foliage while their larv live underground on roots4 ,the following species are outstanding3-- ,,cockchafers4--,these are the adults of the grass grubs1 and there are several species1 all native to ,new ,zealand4 ,the commonest and most destructive one 7,fig4 #aa1 #a;a7 is the so-called brown beetle 7,odontria zealandica71 misnamed the 8turnip fly10 which is on the wing for about six weeks each year1 during ,november and early ,december as a rule4 ,it swarms at dusk1 creating a loud1 droning sound1 and is responsible for widespread damage by defoliating garden plants and field crops1 as well as trees4 ,illustration3 ,,fig4 #aa4 7#a7 a1 ,brown-chafer beetle2 b1 antenna of beetle1 showing finger-like processes2 c1 larva or grass grub4 7#b7 ,bronze beetle4 7#c7 a1 ,gum-tree weevil2 b1 egg capsule2 c1 larva4 7#d7 ,eucalyptus tortoise beetle4 7#e7 a1 ,pear saw-fly2 b1 larva from the side2 c1 larva from above4 7#f7 ,pear midge4 ,this beetle is easily identified4 ,it is rather plump-bodied1 brownish1 smooth1 and measures about three-eighths of an inch long4 ,like all beetles1 the front wings are hard1 and form a cover over the body when closed2 these hardened wings1 or elytra1 do not reach quite to the end of the abdomen1 the tip of which remains uncovered4 ,another definite character is found in the antenn1 which terminate in finger-like processes 7,fig4 #aa1 #a;b74 ,there are several species of cockchafers1 to which all these characteristics1 except the colour1 might be referred1 but none is so abundant as the species under review4 ,there is one1 however1 that is on the wing about the same time as1 or a little earlier than1 the brown beetle4 ,this species is somewhat larger1 about half an inch long2 it is sparsely clothed with hair1 and the elytra are marked by broad brown stripes1 alternated with very narrow darker ones4 ,the brown beetle lays its spherical eggs in the ground1 preferably amongst the roots of grass1 strawberries1 etc4 ,the grubs 7,fig4 #aa1 #a;c7 are well known as grass grubs2 they are whitish in colour1 the swollen terminal segment of the abdomen being very often darker4 ,these grubs are sometimes called 8curl-grubs10 from their habit of lying doubled-up when at rest or feeding in the ground4 ,towards ,september each year the grubs of the brown beetle pupate prior to the beetles emerging in ,november4 ,these grubs will be referred to later under the chapter dealing with subterranean insects4 ,in gardens and nurseries1 the depredations of the beetles may be lessened by spraying with lead arsenate1 or by the use of sulphur smudges4 ,the use of smudges was developed very effectively as follows by ,mr4 ,d4 ,j4 ,buchanan1 forest ranger at the ,tapanui ,state ,forest nurseries4 ,sulphur is spread on strips of scrim1 which are then rolled up and placed in containers1 such as old paint pots4 ,the latter are set about the nursery1 and fired at evening1 when they will burn throughout the night1 the fumes acting as a deterrent to the beetles4 ,when only a few plants are to be protected1 such as bush roses1 the beetles can be warded off by allowing a hose to play over the plants throughout the night4 ,another common cockchafer which is on the wing most of the summer and autumn is the green manuka beetle 7,pyronota festiva74 ,this insect is capable of causing considerable damage as a defoliator4 ,it is active both day and night4 ,the general colour is bright green1 with a dark stripe down the middle of the back1 though some specimens are brown or coppery2 the legs are orange-yellow1 and the length of the insect is a little over a quarter of an inch4 ,,bronze ,,beetle7,eucolaspis brunneus74--,this insect 7,fig4 #aa1 #b7 is very often confused with the brown beetle1 from which1 however1 it is easily distinguished4 ,it is active during the day1 and attacks the foliage and fruit of a great variety of plants1 eating holes from leaves1 so that the latter appear as if they had been subjected to a charge of shot1 or devouring the epidermis from fruits and berries4 ,this beetle is active during ,november to ,january2 it measures about one-sixteenth of an inch long1 is oval in outline1 and varies in colour from yellowish1 with darker markings1 to greenish or bronzy-black2 the antenn are comparatively long1 and do not terminate in any unusual manner1 as do those of the cockchafers4 ,a characteristic habit of the bronze beetle is to leap off the plant if disturbed2 this habit has been responsible for the group to which this insect belongs being called 8flea beetles40 ,the bronze beetle lays its eggs in the ground1 where the larv feed1 though they are not injurious in that stage4 ,the beetles are to be controlled by the use of lead arsenate4 ,,gum ,,tree ,,weevil7,gonipterus scutellatus74--,both the adults and larv of this ,australian weevil attack eucalyptus foliage1 particularly bluegum1 in most parts of ,new ,zealand1 the adult weevils eating from the leaf margin1 as well as devouring tender shoots1 while the larv cut elongated holes from the leaf surface4 ,the weevil 7,fig4 #aa1 #c;a71 which is of a tawny to brownish-black colour1 and clothed with yellowish-white and golden hairs1 measures from a quarter to one-third of an inch in length2 it possesses a short snout on the head4 ,the eggs are yellowish1 and are packed in a hard1 black capsule 7,fig4 #aa1 #c;b71 attached mainly to the surface of young leaves4 ,the larv 7,fig4 #aa1 #c;c7 are legless1 like those of all weevils1 and yellowish at first1 when they are studded with small black dots1 and have a dark stripe along each side4 ,frequently these young larv are seen with a tail-like thread of blackish excrement projecting from the posterior end4 ,the plump1 fully-developed grub is yellowish-green1 with a wrinkled skin1 and is slug-like in general appearance4 ,pupation takes place in the ground4 ,this insect over-winters in the adult stage1 and large numbers of the weevils are very often to be found beneath loose bark on the tree trunks during the winter4 ,control depends upon the use of an egg parasite which has been established in certain localities of the ,dominion4 ,in the case of small ornamental trees1 spraying with lead arsenate to which laundry soap has been added should be effective4 ,,eucalyptus ,,tortoise ,,beetle7,paropsis dilatata74--,this is another ,australian insect restricted so far to the ,east ,coast districts of the ,south ,island1 where it attacks eucalyptus foliage in company with the weevil4 ,the beetle 7,fig4 #aa1 #d7 is tortoise-shaped1 varies in colour from reddish-yellow to reddish-brown1 with darker markings on the back1 which is pitted by minute depressions1 and has a length of from one-third to half an inch4 ,like the weevil1 this beetle passes the winter beneath loose bark4 ,the eggs are conspicuous and cigar-shaped1 being laid in clusters1 lying more or less on their sides1 upon the foliage4 ,the larva is rather plump1 and pointed posteriorly2 it possesses legs1 while at the tip of the body is a sucker-like false foot4 ,the general colour is yellowish1 varying to a rosy-pink1 there being a darker stripe down the back1 while along each side is a similar one above a row of black dots4 ,,pear ,,and ,,cherry ,,slug1 ,,or ,,saw-,,fly7,caliroa limacina74--,the slug-like larv of this insect are very abundant upon hawthorn foliage1 and if not controlled do considerable damage to cherry1 plum1 pear1 and peach4 ,these larv 7,fig4 #aa1 #e;b7 are very often called leeches1 and devour the epidermis1 exposing the skeleton of the infested leaves2 they are slimy1 of a dark green1 though orange-coloured immediately after a moult1 and the head end is much enlarged1 giving a clubbed shape to the body1 along the under side of which are several false legs4 ,pupation takes place in the ground4 ,the adult 7,fig4 #aa1 #e;a7 measures about a quarter of an inch long1 is rather thickly set1 black in colour1 and possesses four transparent wings4 ,the female deposits her eggs in the tissue of the foliage by means of a saw-like ovipositor--hence the name 8saw-fly0--which is thrust through the lower epidermis of the leaf1 when a pocket is formed to receive the egg2 each egg pocket forms a little pimple on the upper surface4 ,this insect is very easily controlled by spraying foliage infested by the larv with lead arsenate4 ,another saw-fly closely related to the foregoing species is the willow saw-fly 7,pontania proxima74 ,this species has only recently appeared in ,new ,zealand1 and its larv live in galls1 or swellings1 on the foliage of willows4 ,,pear ,,midge7,perrisia pyri74--,a serious pest of pear trees1 which for some years retarded the culture of pears1 especially in the ,auckland district1 is the pear midge4 ,this is a minute1 delicate1 two-winged fly 7,fig4 #aa1 #f71 measuring about one-twenty-fifth of an inch long2 it has a blackish head and thorax1 and an orange-red to brownish abdomen4 ,the female alights upon young leaves just burst from the bud2 and1 while they are yet curled1 lays her eggs between the folds4 ,the larv1 on hatching1 live protected in the curled leaves1 which they attack1 and which never unfold4 ,the result is that the infested leaves eventually turn black and brittle1 and cease to function4 ,the fully-developed larv drop to the ground1 which they enter1 and there pupate4 ,the midges become abundant in early spring1 when the first young pear foliage develops1 and they keep on producing generation after generation until the autumn4 ,the winter is passed in the larval stage underground beneath the trees4 ,a parasite has been established against the pest1 and is doing good work4 ,the insect can be reduced to a large extent by thorough winter cultivation1 especially beneath the trees4 ,the insect's larv1 being protected within the curled-up leaves1 are not reached by ordinary sprays1 but ,dr4 ,r4 ,h4 ,makgill1 of ,henderson1 secured some excellent results on young trees by the use of nicotine4 ,,olearia ,,gall ,,midge7,cecidomyia oleari74--,in many parts of ,new ,zealand where ,olearia forsteri is grown as a hedge1 it is very often disfigured by the formation of malformations1 or galls4 ,these are caused by a native midge known as the olearia gall midge4 ,the midge itself resembles the pear midge in structure1 but is larger1 measuring from one-tenth to one-eighth of an inch long2 it is conspicuous on account of its black thorax and blood-red abdomen4 ,in early spring the midges appear and lay their conspicuous masses of bright red eggs upon the buds of the developing shoots4 ,the larv1 on hatching1 set up an irritation in the rapidly-developing tissues1 causing the latter to swell and become malformed into bunches of rosette-like galls4 ,if the latter are cut open1 a number of the yellowish larv will be found1 each in its own compartment within the fleshy gall4 ,there is only one brood of adults each year4 ,control can be effected to a great extent by cutting back and burning the badly-infested parts during winter1 and by pruning the young growth carrying the eggs in the spring4 ,spraying with nicotine when the midges are active should also help to protect the plants4 ,,chapter ,,viii4 ,boring and ,underground ,insects4 ,,codlin ,,moth7,cydia pomonella74--,the codlin moth caterpillar burrows in developing apples and pears1 and such 8wormy0 fruit is known to everybody4 ,the moth itself is seldom seen1 since it lies concealed until after nightfall1 when it becomes active and lays its eggs4 ,the insect 7,fig4 #ab;a7 measures about three-quarters of an inch long1 and is inconspicuously1 though beautifully1 coloured2 the fore wings1 which cover the body when closed1 are light grey1 crossed by fine bands of a darker hue1 giving the appearance of watered-silk1 while at the extremity of each wing is a large bronze spot2 the hind wings1 seen only when expanded1 are of a light brown colour4 ,the minute flat eggs are laid on the foliage of leaves1 on the fruit1 or even on young bark2 they appear at first as glistening white specks1 but1 as development advances1 a red ring develops1 and finally a black spot just prior to the caterpillars hatching4 ,in some places the first larv developing in the spring enter the fruit by way of the calyx1 but under ,new ,zealand conditions it is more usual for entry to be made by boring through the skin of the apple4 ,having completed their development in the fruit1 the caterpillars bore their way out and spin their cocoons beneath the loose bark of the tree trunks2 in these cocoons pupation takes place1 and from them the next generation of moths develops4 ,although in ,new ,zealand there is usually only one generation produced each year1 three or even four develop in other countries4 ,the winter is passed by the larv in their cocoons1 and pupation takes place just prior to the period when the moths emerge in the spring4 ,as the moths continue to emerge and lay their eggs for a period extending from ,november to ,february1 it is essential that regular applications of arsenate of lead be made during that time in order to protect the fruit from the larv hatching from the eggs laid by the moths4 ,in localities where the spring larv enter the calyx of the fruit1 it is essential to apply the first spray just after the petals fall1 so that the poison may lodge in the calyx before it closes4 ,the removal of rough bark from the trunks of both apple and pear trees is a help in controlling the insect4 ,another method sometimes used is to band the tree trunks with strips of scrim2 under these bands the larv collect1 and the former can be later removed and destroyed with their tenants4 ,,currant ,,clear-,,wing ,,borer7,sesia tipuliformis74--,this destructive moth has been carried to and established in ,new ,zealand1 as well as many other parts of the world4 ,in currant gardens its larv cause the death of canes by eating out the pith4 ,the moth 7,fig4 #ab;b7 is a very conspicuous and beautiful insect2 the wings1 which expand to about three-quarters of an inch1 are transparent and bordered with golden-purple1 a bar of the same colour crossing the surface of the fore wings2 the body 7about half an inch long7 is metallic-purple1 the thorax having a yellow stripe on each side1 while the abdomen1 barred with golden bands1 terminates in a fan-shaped tuft of purplish hairs4 ,the moths are active each year in the spring1 when they lay their brownish1 globular eggs singly on the bark of the currant canes4 ,the resultant larv bore into the stem and destroy the pith1 passing the winter in the damaged canes4 ,in the following spring the larv become active once more and approach the surface1 where pupation takes place shortly before the moths emerge4 ,there is only one generation each year1 and control lies in the removal and burning of infested canes in late winter4 ,,tomato ,,stem ,,borer7,gnorimoschema plsiosema74--,tomato growers are frequently faced with the problem of the destruction of tomato plants caused by the attacks of the larv of the tomato stem borer moth4 ,this insect caused considerable damage for the first time in ,auckland some fourteen years ago1 though it was known in other parts of the country as well4 ,the moth itself 7,fig4 #ab;c7 is a small one1 measuring about a quarter of an inch with the wings closed4 ,in this position the insect is wedge-shaped and conspicuous4 ,against the general greyish-brown colour is a dark brownish area on each side4 ,the eggs are laid on the tomato leaves1 in which the young caterpillars tunnel as they work toward the leaf petioles1 down which they burrow into the main stems4 ,in the damaged stems1 pupation takes place4 ,under favourable conditions1 this insect may pass through at least three generations during the season4 ,control depends upon sanitation and the use of arsenate of lead sprays4 ,all infested stems1 together with plants after the crop has been removed1 should be burned2 as the insect is known to attack potato plants and tubers1 care should be taken to destroy all potato tops after harvesting4 ,frequent applications of arsenate of lead are essential to protect the tomato plants1 especially during the earlier part of the season4 ,when on this subject1 mention should be made of the potato-tuber moth 7,phthorima operculella71 which is somewhat similar to the tomato-stem borer1 both in appearance and habits4 ,the larva of this insect is best known from its habit of boring through potato-tubers2 these burrows become filled by a fungus after the larv have vacated them4 ,the adult potato-tuber moth is a night-flyer1 and lays its eggs upon the leaves of the plants2 the larv burrow down the stems1 and may even reach the tuber below ground4 ,when seed is not properly buried1 the moth will also lay its eggs in the 8eyes10 and so directly infest the tuber2 this danger applies also to potatoes in store or in bags4 ,in the control of the potato-tuber moth1 the following points should be noted3--,select only sound seed and cover well when planted4 ,on harvesting the crop1 do not leave the bagged potatoes standing in the field overnight1 as they are exposed to infestation2 neither cover the open bags with the potato-tops1 as is commonly done1 since this will attract the moths4 ,destroy all tops immediately after harvesting4 ,dusting potatoes in store with slaked lime will tend to act as a protection against the moth4 ,illustration3 ,,figure #ab4 ,a--#a1 ,codlin moth2 #b1 codlin larva in apple4 ,b--#a1 ,currant clear-wing moth2 #b1 clear-wing moth larva in stem4 ,c--#a1 ,tomato stem-borer moth2 #b1 larva of moth2 #c1 damaged tomato stem4 ,d--#a1 ,a long-horn beetle2 #b1 larva of long-horn beetle4 ,e--#a1 ,a leaf-mining fly2 #b1 leaf attacked by leaf-miner4 ,f--#a1 ,subterranean grass-caterpillar moth2 #b1 subterranean grass-caterpillar4 ,g--#a1 ,a click beetle2 #b1 a wire-worm4 ,h--#a1 ,larger narcissus fly2 #b1 smaller narcissus fly4 ,k--#a1 ,a subterranean spring-tail2 #b1 a leaf-eating spring-tail4 ,,round-,,headed ,,borers4--,apple1 almond1 and citrus trees1 together with gooseberry and such ornamental and shelter trees as poplars1 tree-lucerne1 and goat-willow1 are sometimes damaged by round-headed borers1 which tunnel in the stems and branches4 ,these borers 7,fig4 #ab;d7 are white in colour1 narrow-bodied1 and cylindrical1 the segments being usually well defined1 and belong to a group of beetles known as long-horned beetles1 a group of insects to which the common hu-hu beetle belongs4 ,these beetles are narrow-bodied1 and their antenn are comparatively long and conspicuous4 ,to control these pests1 the only thing to do is to cut out and burn the badly-infested parts4 ,where a borer is located 7and this can be frequently done by the presence of the powdered wood ejected from the burrows71 the culprit may be killed by injecting into the tunnel some carbon bisulphide and plugging up the openings with some clay or other similar substance4 ,,leaf-,,mining ,,flies4--,very often the leaves of cineraria and chrysanthemum are disfigured by the tortuous tunnellings of the maggots of minute flies 7,fig4 #ab;e74 ,the adult insects are two-winged1 and in structure resemble in many respects miniature houseflies4 ,the eggs are laid in the leaf tissues1 in which the whole development of the maggots and pup takes place4 ,the white maggots are small1 legless and headless4 ,spraying with black-leaf #dj would act as a deterrent to the flies1 while infested leaves should be removed and destroyed before infestation becomes general4 ,,grass ,,grub7,odontria zealandica74--,as explained in the preceding chapter1 the grass grub is the larva of a native cockchafer beetle 7,fig4 #aa1 #a74 ,this grub1 by feeding upon roots1 causes extensive damage to pastures and lawns1 as well as to many garden plants1 including strawberries4 ,in the case of pasture and lawns1 the presence of even a considerable number of grass grubs is not detrimental unless they occur concentrated in definite areas1 when the damage is pronounced4 ,with garden plants1 however1 which are isolated when compared with the dense root masses of grasses1 the attacks of one or two grubs upon the roots of a single plant may cause serious injury4 ,grass grub damage to grasses is not merely due to attack upon the roots4 ,while feeding1 the grubs swallow soil with the roots1 rendering the former spongy1 and so disturb the normal circulation of moisture about the grass roots4 ,in the case of infested lawns1 it is advantageous to roll infested areas in order to pack the soil pulverised by the grubs1 and re-establish normal circulation of soil moisture4 ,another important feature in grub control is to stimulate root development by means of fertilisers4 ,a recently-developed method of 8grub-proofing0 lawns is to broadcast over every thousand square feet of turf to be treated one bushel of screened sand or clean soil1 in which #elb4 of lead arsenate powder have been intimately mixed4 ,this is said to remain effective for a period of three years2 but such fertilisers as nitrate of soda1 superphosphate1 sulphate of potash1 and potassium chloride should not be used on 8grub-proofed0 turf1 as they react with the lead arsenate1 and reduce its effectiveness1 though rotted manure or ammonia sulphate may be used4 ,the control of grass grubs damaging the roots of strawberry and other plants is a difficult matter1 though some benefit is to be derived by making holes about four inches deep with a stick in the soil near to the infested plants and pouring in a little carbon bisulphide2 the holes should be closed immediately4 ,to protect strawberry beds1 if they are not too extensive1 the most satisfactory method is to cover the plants with scrim1 stretched on frames1 at dusk during ,november and early ,december1 when the beetles are flying2 this will prevent the insects from infesting the ground with their eggs4 ,the use of sulphur smudges1 already referred to1 is of great importance in this respect4 ,,subterranean ,,grass ,,caterpillars4--,these caterpillars are the larv of native moths 7,fig4 #ab1 f#a7 belonging to the genus ,porina1 and when they become epidemic they cause much more extensive damage to pasture and lawns than do the grass grubs4 ,when full grown1 the greyish-black caterpillars 7,fig4 #ab1 f#b7 reach a length of about three inches2 they are soft-bodied and rather flaccid1 and live in underground burrows of varying depth4 ,after dark1 these caterpillars come to the surface and devour the grass1 eating it close to the ground1 much soil being swallowed by the larv during the feeding4 ,this soil is evacuated1 and resembles earthworm castings1 but is mixed with silk spun by the caterpillars2 the emergence holes of the caterpillars1 about the diameter of a lead pencil1 are conspicuous on the surface denuded of its covering of grass4 ,pupation takes place underground1 and when the moths emerge the pup first move to and project beyond the surface of the ground2 these pup are large and easily recognised by the wing-cases1 which are very short compared with the length of the body4 ,the moths are on the wing during spring and summer1 the rest of the year being spent in the larval stage4 ,the moths are night-flyers1 and are amongst the largest species in ,new ,zealand1 their wings having an expanse of from one to over two inches2 they are heavy-bodied insects1 and vary considerably in colour4 ,one of the commonest1 species is brownish-yellow1 or sometimes a smoky-grey1 with a white streak bordered with black on the fore wings2 the hind wings may be pinkish4 ,the most satisfactory method of controlling the insect is to roll infested lawns after dark1 in order to crush the caterpillars whilst feeding on the surface4 ,flooding an infested lawn with water will bring most of the caterpillars to the surface1 when they can be collected and destroyed4 ,spraying grass in spring and early summer with arsenate of lead will tend to poison the immature caterpillars4 ,there are at least three species of insect parasites that attack these larv1 and there is also a fungus which invades and destroys the whole body1 taking the shape of the insect2 such fungus-infested caterpillars are commonly called 8vegetable caterpillars40 ,,wireworms4--,the roots of garden plants and germinating seeds are often damaged by hard1 wiry beetle grubs1 reddish-brown or whitish in colour1 called 8wireworms10 so named from their resemblance to short pieces of wire2 they have three pairs of legs behind the head and a sucker-like appendage on the last body-segment 7,fig4 #ab1 g#b74 ,these grubs transform to narrow-bodied1 brownish or blackish beetles1 known as 8click-beetles0 7,fig4 #ab1 g#a7 from their habit1 when overturned1 of righting themselves by a springing action1 during which a distinct and sharp clicking sound is made2 the spring apparatus consists of a spine1 the tip of which fits into a notch on the under side of the thorax4 ,practically nothing is known as yet in regard to the biology of the ,new ,zealand click-beetles4 ,they are extremely difficult to control1 and the larval stage covers a period of two or more years4 ,,narcissus ,,flies4--,there are two species of narcissus flies--the larger 7,merodon equestris7 and the smaller 7,eumerus strigatus7 both occur in ,new ,zealand4 ,the larv of these flies attack bulbs of various kinds1 the hosts of the larger fly being narcissus1 hyacinth1 tulip1 amaryllis1 habranthus1 vallota1 galtonia1 scylla1 and leucojum2 and of the smaller fly1 narcissus1 hyacinth1 onion and shallot4 ,these flies are two-winged insects1 the hind wings being wanting as such1 and belong to a group called the syrphid1 or hover flies4 ,the larger narcissus fly 7,fig4 #ab1 h#a7 resembles somewhat a humble-bee 7which1 however1 has four wings72 its stout and very hairy body measures about half an inch long4 ,there is considerable variation in colour1 though black or brown predominates1 with greyish or yellowish hairs1 and bands of the same colour2 the bands1 however1 are absent in some individuals4 ,during spring the insects fly about in the sun1 and lay their eggs at the leaf bases of the host plants1 or on the exposed neck of bulbs1 or in the soil close by4 ,the larv1 which are legless1 yellowish grubs1 enter the bulb1 and may completely destroy it4 ,infested bulbs may be detected by an unnatural softness near the neck when pressed between the fingers4 ,the smaller narcissus fly 7,fig4 #ab1 h#b7 is about half the length of the larger1 of a shiny black colour1 with metallic reflections1 and is not clothed with hair4 ,the eggs are laid in the ground1 or at times upon the plant itself4 ,several larv of this fly may be found in the one bulb2 the larv resemble those of the larger fly1 but are smaller1 and have three small processes at the end of the body4 ,the smaller narcissus fly usually attacks the bulbs already damaged by some other agent1 though it has been known to infect sound bulbs4 ,control of both these flies depends upon the destruction of infested bulbs4 ,recent researches have shown that the flies themselves can be poisoned in large numbers by a spray made of #doz4 of sodium arsenate1 #alb4 of crude glycerine1 #blb4 of white sugar1 and four gallons of water2 this spray is applied during bright and warm weather4 ,,springtails4--,these are very minute1 soft-bodied insects1 which are very active1 and have a habit of springing with the agility of fleas4 ,there are several species1 but two are of interest to the horticulturist4 ,one of these 7,fig4 #ab1 k#a7 is white in colour1 narrow-bodied1 and lives underground1 especially in damp places1 where it damages germinating seeds1 or the roots of seedlings2 even older herbaceous garden plants are attacked4 ,as a control1 it is important to drain the soil in damp locations and to dig in calcium cyanide about two weeks before planting or sowing4 ,the second species is blackish and more or less spherical 7,fig4 #ab1 k#b72 at times it does considerable damage in the spring to the seed-leaves of young plants as soon as they appear above ground4 ,spraying small areas--e4g41 of cucumbers1 turnips1 etc4--with black-leaf #dj would help to protect the plants2 as the eggs are laid in the ground1 and as these develop best under moist conditions1 thorough cultivation prior to sowing the crop is an important controlling factor4 ,,chapter ,,ix4 ,miscellaneous ,pests4 ,in this chapter will be grouped for convenience mites1 woodlice1 millepedes1 slugs1 snails1 and eelworms4 ,mites4 ,mites1 together with spiders and ticks1 belong to a group of animals distinct from the insects1 from which1 they differ in many respects2 for example1 they possess four1 and not three1 pairs of legs in the adult state1 no head separated from the body as a movable1 distinct region1 while in many cases1 especially in mites and ticks1 the abdomen and thorax are continuous2 in no case are wings developed4 ,mites are of small size1 some being microscopic1 while others are just discernable by the unaided eye4 ,all species have the mouth-parts developed for the purpose of feeding upon liquid food--e4g41 blood 7in the case of those species that attack animals71 decaying vegetable matter1 or the saps of plants4 ,it is the last--that is1 those parasitic upon plants--with which we are here concerned4 ,the life-history of mites presents some variability1 and1 though there are fundamentally four stages of development1 additional stages have been developed by some species which tend to complicate the cycle4 ,the principal stages in development are as follows 7,fig4 #ac1 #a-e73--;,in practically all cases eggs are deposited1 but few species being viviparous4 ,the larva1 on hatching1 possesses but six legs1 and resembles an insect in this respect2 the larva then becomes quiescent1 and after moulting the eight-legged nymph appears4 ,while in the nymphal state the mite may undergo one or more moults1 giving rise to additional nymphal forms1 that may complicate the life-history4 ,from the final moult of the nymph the adult mite emerges4 ,perhaps the best-known mite in ,new ,zealand is the ,european red mite of apple trees 7,paratetranychus pilosus71 though it attacks a wide range of plants apart from deciduous fruit trees1 which it favours2 it has been found on grape vine1 raspberry1 rose1 hawthorn1 citrus1 etc4 ,this mite 7,fig4 #ac1 #f7 occurs in ,europe1 ,russia1 ,british ,isles1 ,north ,america1 ,australia1 and ,new ,zealand1 and it causes considerable injury to foliage1 which assumes a brown appearance1 owing to the tissues drying up where they have been punctured by the mouth-parts of the mite4 ,in the case of heavily-infested trees1 the red eggs of this mite form conspicuous patches on the bark during winter2 these winter eggs are laid from ,january onward till leaf-fall1 and from them the young mites hatch in the spring1 when the foliage is again attacked4 ,the red mite develops rapidly1 and reaches the adult stage in about two weeks2 several generations are thus produced from spring to autumn1 when the eggs are laid upon the foliage4 ,the eggs 7,fig4 #ac1 #g7 are very small1 globular1 and ribbed on the surface2 from the centre of each projects a hair-like stalk1 somewhat bent at the tip4 ,the colour is bright red1 changing to a deep orange4 ,the red mite lives freely upon the foliage1 and does not produce a web1 as do related species2 the adult female is bright red to dark brownish-red1 rather globular in shape1 with comparatively stout legs and numerous spine-like hairs on the back4 ,although the eggs of the ,european red mite are exposed on bark and readily accessible to sprays during the winter1 no effective winter wash for their control is yet known2 the most satisfactory method for checking the pest is to spray the active stages of the mite with summer oil4 ,another species of mite1 having much the same habits and host plants as the ,european red mite1 is the brown mite 7,bryobia prtiosa74 ,the eggs of this species are of a deep red1 with a yellowish tinge in many cases1 but differ from those of the ,european red mite in the absence of the polar-stalk and ribbed surface4 ,the brown mites 7,fig4 #ac1 #h7 are of a dull red or greenish colour1 lack the spine-like hairs on the back1 are decidedly flattened1 and have the front pair of legs abnormally long4 ,the common red spider 7,tetranychus telarius7 is a species of mite frequently met with on a wide range of plants too numerous to mention here2 in ,new ,zealand it frequently injures violet1 hop1 currant1 willow1 and many weeds4 ,this mite is to be found in all stages practically all the year round2 during the spring it is mostly found on weeds and such cultivated plants as strawberry and violet4 ,it is a web-spinning species1 and the minute yellowish-red eggs are to be found scattered among a fine web attached to the lower surface of leaves as a rule4 ,the adult mite 7,fig4 #ac1 #i7 is very active2 it is somewhat larger than the two foregoing species1 and of a yellowish-green colour1 with a pair of conspicuous dark spots on the back4 ,though this mite can be held in check by the application of lime-sulphur sprays1 advantage should be taken of thorough cultivation during the dormant season1 since the mite hibernates on weeds and among dead leaves and in the soil4 ,a mite very often met with by bulb growers is the bulb-mite 7,rhizoglyphus hyacinthi71 now found in most parts of the world4 ,although this mite may possibly be able to attack practically all tubers or bulbs1 it is commonly found infesting narcissus1 hyacinth1 tulip1 crocus1 and ,easter lily2 it is especially abundant in bulbs with loose scales1 and has been found to be capable of attacking healthy tissue4 ,the life-history of this species is complicated at times by the development of additional stages2 one of these--the hypopus--is of particular interest1 as it shows more activity than the others1 and attaches itself to the bodies of insects1 and is so transported4 ,the mite develops from egg to adult within a period of nine days under favourable conditions1 or as long as six weeks at other times4 ,all stages of the bulb-mite occur at the same time in infested bulbs1 which become soft and rotten4 ,the adult mites 7,fig4 #ac1 #aj7 are smooth1 yellowish-white1 tinged with pink1 and have legs and mouth-parts reddish4 ,symptoms of their presence are to be found in stunted growth and yellowing leaves1 failure of flower development1 reddish spots on bulb scales1 or a softening of the bulbs4 ,all seriously-infested bulbs should be destroyed1 and the ground where they were grown treated with calcium cyanide4 ,for the treatment of bulbs1 they should be immersed for ten minutes in a two per cent4 solution of formalin heated to #abb deg4 ,fahr41 or simply in water at a temperature of #aca deg4 ,fahr4 ,illustration3 ,,fig4 #ac4 7#a7 ,five stages in mite development3 7#a7 ,egg1 7#b7 larva1 7#c7 nymph1 7#d7 older nymph1 7#e7 adult mite4 7#f7 ,european red mite and 7#g7 egg of same4 7#h7 ,brown mite4 7#i7 ,common red spider4 7#aj7 ,bulb mite4 7#aa7 ,pear-leaf blister mite4 7#ab7 ,common woodlouse4 7#ac7 ,garden millepede4 7#ad7 ,garden slug4 7#ae7 ,garden snail4 7#af7 ,bulb eelworm4 7#ag7 and 7#ah7 ,immature and mature beet eelworm4 7#ai7 and 7#bj7 ,immature and mature root knot eelworm4 ,another group of mites of importance to the horticulturist is that of the blister mites2 they are so minute--measuring about a hundred-and-fiftieth of an inch long--as to be invisible to the unaided eye4 ,though so minute1 however1 their damage to foliage is characteristic and conspicuous1 so that their presence is easily detected4 ,the most important blister mite in ,new ,zealand is the pear-leaf blister mite 7,eriophyes pyri72 it differs from the other mites described above in having a long and cylindrical body1 with only two pairs of legs crowded at the head end1 the elongate abdomen having the appearance of being composed of innumerable segments 7,fig4 #ac1 #aa74 ,this mite lives in colonies in blisters formed on the leaf1 and sometimes on the leaf petioles4 ,in the spring the yellowish-green blisters will give the upper surface of an infested leaf a spotted appearance1 and as the season advances these blisters become reddish and finally brown2 in the case of severe infestation1 the blisters become so crowded as to merge into masses4 ,during the winter the mites lie in the shelter of the bud scales2 as soon as the foliage begins to develop in the spring the over-wintering mites attack the leaves1 each mite forming a blister1 in which it produces a colony of young4 ,the offspring then migrate from the parent blister and form blisters for themselves1 and this goes on until autumn1 when the last generation of mites migrates for the winter to the shelter of the bud scales4 ,owing to the mites being protected within the leaf blisters1 summer sprays are not effective as a means of control1 which can be effected1 however1 by spraying with lime-sulphur in the autumn1 when the mites are taking up their winter quarters1 and again at bud movement in the spring4 ,woodlice4 ,woodlice are so well known1 that but little description is necessary here4 ,however1 the following features are of interest4 ,they belong to the group of animals known as the ,crustacea1 which also includes the crabs2 these animals breathe by means of gills1 and are usually aquatic1 but some forms1 such as the woodlice1 have become adapted to a life on land4 ,in outline 7,fig4 #ac1 #ab7 the woodlice are more or less oval1 with the upper surfaces somewhat arched1 and the lower flat2 the body is divided into several segments1 which may enable the animals to curl up in the form of a pill4 ,there is a distinct head1 bearing a pair of antenn and the mouth-parts1 followed by seven large thoracic segments1 to each of which a pair of legs is attached2 finally1 the remaining six segments are more or less crowded together1 and constitute the abdomen4 ,since woodlice are terrestrial gill-breathing animals1 moisture is essential for them1 and it is in moist places that they abound4 ,they depend upon a mixed diet1 being carnivorous1 as well as herbivorous2 though normally scavengers1 their attacks upon seedlings and tender parts of plants bring them into the ranks of important garden pests4 ,woodlice hibernate under any convenient shelter2 in the spring1 eggs are produced and carried by the female on the under side of the body until the young woodlice hatch4 ,during growth the cuticle or shell is periodically cast1 and a freshly-moulted woodlouse is white in colour4 ,the best method of control is garden sanitation1 all rubbish likely to harbour the woodlice being removed4 ,since they are nocturnal1 the woodlice can be trapped by means of moss laid on the ground2 the moss in which the woodlice have taken shelter is collected during the day and burned1 or immersed in hot water to kill the animals1 when it can be used again4 ,some good results have been secured by means of sliced potatoes dipped in arsenate of lead or ,paris green2 the potatoes are placed within reach of the woodlice1 which are attracted to and feed upon the poisoned bait4 ,horse manure should not be used in seed beds likely to be infested by woodlice4 ,millepedes4 ,millepedes are short1 worm-like animals1 with a fringe of numerous short legs on each side 7,fig4 #ac1 #ac71 and have a characteristic habit of curling up when disturbed4 ,though scavengers for the most part1 feeding upon decaying vegetation and on small organisms1 they may do considerable damage to sprouting seeds1 seedlings1 and to tender plants2 they are particularly abundant in damp and warm soil1 where there is an abundance of rotting vegetable matter4 ,having a keen sense of smell1 millepedes are readily attracted to poisoned bait in the form of sliced potato spread with ,paris green3 another method is to place a piece of freshly-cut potato under an inverted flower pot1 to which the millepedes will be attracted1 when they can be collected and destroyed4 ,a satisfactory control measure is to treat infested soil with black-leaf #dj1 using one part in one thousand parts of water4 ,slugs and ,snails4 ,plants are very often greatly damaged by the depredations of slugs and snails2 frequently young plants are devoured as soon as they appear above ground4 ,these animals attack the plants after nightfall1 and during the day seek cover4 ,though slugs will shelter in the soil1 they1 together with snails1 will shelter in any convenient place1 such as under old boards1 sacking1 bricks and stones upon the ground1 or under large leaves or amongst rank herbage--indeed1 in almost any place that affords cover and moisture4 ,slugs and snails are especially active during wet weather1 and at such times1 owing to the overcast conditions1 they will continue their depredations in the daytime4 ,though slugs are active throughout the year1 and even during winter when the temperature is favourable1 snails pass the winter1 as well as hot1 dry spells in summer1 in a dormant state1 often being found together in sheltered positions where the conditions are dry4 ,both slugs and snails copiously secrete a slimy substance1 that affords them protection against chemicals used for purposes of control4 ,in the case of the slug 7,fig4 #ac1 #ad71 the shell is small and inconspicuous1 but the large spiral shell of the snail 7,fig4 #ac1 #ae7 affords the animal adequate protection1 into which it withdraws itself in times of danger4 ,both slugs and snails reproduce by means of eggs2 these are white1 spherical and opaque1 and are deposited in the soil or under decaying vegetation4 ,one of the best means of control is to dust the plants with powdered tobacco4 ,another method is to treat infested plants with soot or lime1 but this must be done at night1 and the material used must come into actual contact with the pests4 ,an effective poison bait1 but one that requires to be carefully handled1 owing to its poisonous nature1 is a mash made of #flb4 of bran mixed with #alb4 of arsenate of lead and an equal weight of treacle2 this is made into a stiff paste1 water being added if necessary4 ,lumps of this mash are placed about the plants to be protected4 ,as a barrier to prevent the inroads of slugs and snails1 plants may be surrounded by a belt of calcium cyanide2 this would have to be replaced each night1 and the utmost care taken in handling1 since the substance and the gas evolved from it are highly poisonous2 out of doors1 however1 the gas1 being diluted with air1 would not be very injurious as long as one did not stand over the treated ground longer than was necessary for laying the cyanide4 ,apart from the above methods1 the key to the control of slugs and snails is 8clean farming0--that is1 the removal of all places1 such as rubbish and rank vegetation1 where the animals will find shelter2 the compost heap is a favourite breeding place1 and this should be turned over at intervals and dressed with lime4 ,eelworms4 ,eelworms are minute1 unsegmented worms1 related to the parasitic thread-worms of animals1 and are abundant in soil and water2 it is usually the surface layers of the richer soils that are inhabited by them4 ,of the long list of species1 only a few are destructive to vegetation1 but these constitute one of the greatest problems of the horticulturist4 ,it is thought that the injury caused to plants by eelworms is toxic rather than mechanical1 and some plants apparently are capable of producing anti-toxins1 which neutralise the toxins of the eelworms2 such plants possess an immunity4 ,there are three important species in ,new ,zealand4 ,the so-called bulb-eelworm 7,anguillulina dipsaci7 attacks more than two hundred kinds of plants1 but is of especial interest to the horticulturist on account of its attacks upon hyacinths1 daffodil1 narcissus1 and gladiolus1 causing deformity and rotting of the tissues 7,fig4 #ac1 #af74 ,it has been found that this eelworm develops from egg to adult within a period of between three and four weeks2 the eggs are capable of lying dormant in the soil for as long as seven years4 ,infested bulbs and corms should be treated by immersion for three hours in water heated to #aaj deg4 ,fahr4 ,potatoes are often damaged by the beet eelworm 7,heterodera schachtii71 which causes what is known as 8potato sickness10 when the growth is retarded1 and wilting takes place2 the root-system shows an abnormal development of secondary or 8hunger-roots40 ,the eggs are retained in the body of the female1 which forms a protective sack or cyst 7,fig4 #ac1 #ag and #ah71 and in this state the eggs pass the winter in the ground1 where they are known to remain dormant for a period of ten years2 under favourable conditions in the spring1 the larv emerge from the eggs and attack the rootlets of suitable host plants1 entering them at the extreme tip4 ,satisfactory methods of control have not yet been developed under field conditions1 but a four-year crop rotation following potatoes is suggested2 seed potatoes from infested ground should not be used4 ,the roots of tomatoes are often found to be a mass of galls1 due to attack by the root-knot eelworm 7,heterodera radicicola71 which also infests tobacco roots as well as other plants 7,fig4 #ac1 #ai and #bj74 ,all stages of this species are to be found in the root galls2 the female lays her eggs in a gelatinous egg sack1 which remains attached to the parent4 ,the larv1 on hatching1 either remain within the parent gall or leave it and enter the soil1 where they seek out and attack the roots of another plant4 ,in tomato gardens steam sterilisation of the soil is the most effective means of control4 ,,chapter ,x4 ,principles of ,pest ,control4 ,in dealing with the control of plant pests1 the objective is to prevent attacks1 or1 when the attacks have established1 to check them as much as possible4 ,in the latter case the term 8exterminate0 is in too frequent use2 it is not usually practicable to exterminate a pest1 and the best that can be done is to check or control it4 ,in the control of animal pests1 it should be borne in mind that the pests are usually associated with other factors inimical to plant life1 such as unthrifty plants1 due to injury or malnutrition1 and fungous and bacterial diseases1 any one of which might be either the primary or secondary cause of plant injury4 ,though at times one method may serve as a means of control1 generally it is a combination of methods that gives the most satisfactory results1 rendering the conditions favourable for the plant and unfavourable for the pests and diseases4 ,the principles underlying control are3-- 7a7 ,garden management4 7b7 ,use of chemicals4 7c7 ,influence of natural enemies4 7a7 ,garden ,management4 ,all parts of plants1 both above and below ground1 are subject to infestation by pests and diseases4 ,under garden conditions1 cultivation is intensive1 and plants are grown year after year on the same ground in surroundings much more sheltered and crowded than in the open field4 ,sound garden management is therefore an important control factor1 and the following features are fundamental3-- ,,condition ,,of ,,soil4--,the vigour of plants is dependent on the soil1 which therefore must be kept in the right state2 it must be well tilled1 and must contain the requisite nourishment and moisture available for plant use1 and as far as possible be free of an abnormal population of root feeding pests1 such as eelworms and the larv of many insects4 ,proper cultivation is therefore the important factor in bringing the soil into the state most favourable to plant life1 as all inimical factors1 including pests1 are reduced4 ,wherever practicable1 as in glass-houses1 soil-inhabiting pests and diseases can be completely controlled by steam sterilisation4 ,,importation ,,of ,,pests4--,one of the readiest methods of infesting a garden is the importation of pests on plants1 and every care should be taken to secure only pest-free stock4 ,in this respect1 also1 must be mentioned the use of stable and barnyard manure1 in which pests such as insect larv1 woodlice and eelworms are introduced2 artificial fertilisers are therefore safer4 ,,overcrowding4--,the tendency to overcrowd1 especially in household gardens1 is to be avoided2 a favourite habit is to plant something in every available space4 ,under such conditions pests and diseases will abound1 and before attempting to spread over a large area1 and so lessen the effect of their depredations1 they concentrate in mass formation within the confines of the garden as long as the food supply lasts2 further1 plants tend to be less vigorous and more susceptible to infestation under crowded than under more open conditions4 ,,injury ,,to ,,plants4--,care should be taken not to injure plants with garden tools during cultivation1 and a clean cut should always be the object in pruning4 ,mechanical injury opens the way for infestation by diseases and some insects4 ,,garden ,,sanitation4--,clean gardening is an extremely important control factor4 ,in most gardens there are rank growths of grass and weeds in out-of-the-way places1 along boundaries1 and bordering cultivated plots4 ,such growths1 especially when the weeds are related to the garden plants1 are always favourite breeding places for many pests that move on to cultivated plants immediately they appear above ground4 ,if these growths are cut and burned in the winter1 and the ground thoroughly dug1 many a spring infestation will be suppressed by the control of hibernating pests2 it is the control of spring infestations that will save a great deal of trouble throughout the summer and autumn4 ,the compost heap1 where garden refuse is dumped until sufficiently rotted1 may be a source of infestation2 not only does it attract and breed many destructive underground pests1 but it may be infested with the spores of diseases harboured by the plant refuse of which it is composed2 it is thus a ready means of reinfesting the soil4 ,diseased and pest-infested refuse should be burned without delay1 and only healthy refuse used for the compost heap if not dug into the ground1 where it will rot4 ,,crop ,,rotation4--,growing the one type of crop on the same piece of ground for several seasons encourages the development of pests and diseases2 but by a rotation of different kinds of plants the continuity of the conditions favourable for the pests and diseases is broken1 and the latter do not have the chance of becoming thoroughly established4 ,,diseases ,,spread ,,by ,,pests4--,it should be borne in mind that the fewer the animal pests1 the less chance there is for diseases to spread4 ,it is now well known that many pests1 though not necessarily epidemic themselves1 are carriers from plant to plant of certain destructive fungous1 bacterial and virus diseases4 ,,co-,,operation4--,in a locality of many gardens a co-operative spirit is essential1 since a single neglected garden in an otherwise well-managed locality will be responsible for discounting the labours of the neighbours4 7b7 ,use of ,chemicals4 ,chemicals are essential in the control of pests and diseases1 and are applied either in the form of sprays or dusts4 ,the former method is the more usual in this country1 but where the water supply is poor dusts tend to take the place of sprays4 ,chemicals used for horticultural purposes are of two distinct kinds--those for the control of animal pests and those for the control of diseases4 ,the commercial horticulturist1 however1 finds it necessary to apply both in the one spray or dust for the dual purpose of controlling both pests and diseases4 ,as the present work is concerned with the pests1 and not diseases1 only those types of chemicals for the control of the former will be referred to4 ,sprays and dusts are of three kinds1 and act upon pests accordingly3 they are either stomach poisons1 or act externally on the animal by actual contact and corrosion1 or cause death by fumigation4 ,the kind used is governed by the feeding habits of the pest2 if the latter is possessed of jaws 7woodlice1 caterpillars1 beetles1 etc471 and feeds by chewing the plant tissues1 then a stomach poison is applied and is swallowed with the food2 if the food is the nutrient sap of plants1 and so could not be poisoned1 a spray acting by contact is used1 as against such animals as aphids 7green fly71 scale insects1 etc41 in which the mouth-parts are not adapted for chewing1 but for puncturing plant tissues to feed on the sap1 much the same as a mosquito punctures one's skin and sucks the blood4 ,fumigants can be used against both the chewing and sucking pests1 the fumes passing into the breathing system4 ,,stomach ,,poisons4--,the chief of these are arsenate of lead and ,paris green1 though the latter has practically gone out of use4 ,arsenate of lead is sold as a paste and as a powder1 and is mixed with water to form a spray1 #clb4 of paste1 or #a-a_/blb4 of powder1 to #ajj gallons of water being the proportions used4 ,for garden purposes1 smaller quantities must be kept to this strength4 ,,contacts4--,the chemicals used in contact control are red oil1 kerosene and lime-sulphur1 but all are also fumigants1 lime-sulphur being also a stomach poison to a limited extent1 though best known as a fungicide4 ,commercial red oils can be purchased ready for mixing with water without the necessity of emulsification1 and the strength at which each brand should be used is given by the manufacturers4 ,though red oils have mostly replaced kerosene emulsion1 many horticulturists still prefer the latter4 ,it is prepared by dissolving #hoz4 of soap in one gallon of hot water1 and then adding two gallons of kerosene1 stirring briskly until emulsification is complete4 ,this is the stock emulsion1 and must be diluted before use1 the strengths being one part to six of water for use in the winter1 and one part to fifteen of water for use in the growing season4 ,commercial brands of concentrated lime-sulphur are on the market1 and the manufacturers' directions for their dilution should be followed4 ,,fumigants4--,the chief fumigants are black-leaf #dj1 carbon-bisulphide and calcium cyanide4 ,black-leaf #dj1 in which nicotine sulphate is the effective principle1 is the most useful fumigant on the market1 and acts as a most effective control for sap-sucking1 and even some chewing pests4 ,the strength at which this fumigant is used is one part in #hjj parts of water1 and is applied as a spray4 ,carbon-bisulphide is a liquid1 the gas evolved from it being an effective fumigant4 ,it is not used as a spray unless emulsified1 its chief use in horticulture being for the fumigation of the soil1 glass-houses1 stored seeds and vegetables1 and imported plants4 ,it is very inflammable and extremely volatile1 especially under higher temperatures1 the heavy gas being highly explosive when mixed with air4 ,the amount of carbon-bisulphide to be used varies1 according to circumstances4 ,for soil fumigation a special type of 8gun0 is on the market for injecting the bisulphide into the soil1 but for ordinary garden purposes it is sufficient to make holes in the ground with a stick1 pour in the fumigant1 and close up the holes4 ,when holes are made about #ah in4 apart1 half an ounce of bisulphide to a hole is sufficient1 the depth of the hole varying according to the depth of the pest to be controlled4 ,for the fumigation of seeds1 bulbs1 potatoes1 etc41 an airtight chamber is necessary4 ,this is also of value in the control of pests of potted plants4 ,the dimensions of a chamber will vary according to the demands made upon it4 ,carbon-bisulphide gas being heavy1 the containers 7shallow dishes7 should be placed on a shelf near the top of the chamber during fumigation4 ,the proportion of fumigant to the air space varies according to the plants and insects to be fumigated4 ,for lawn-infesting insects1 carbon-bisulphide can also be used in an emulsion as a spray prepared as follows3--,fifty grams of powdered resin are gradually added to #ace cc4 of a #g per cent4 solution of sodium hydroxide1 previously warmed2 #dej cc4 of hot water is now added1 and the whole agitated until the resin is completely dissolved1 when #ej cc4 of oleic acid is also added4 ,to prepare the emulsion1 three parts of this soap solution are thoroughly agitated with seven parts of carbon-bisulphide until emulsification is complete1 which can be gauged by the creamy-white colour and viscosity4 ,for use dilute in the proportions of #ah pints of the emulsion with #ej gallons of water1 applying by means of a watering-can or spray-pump at the rate of one gallon to every square foot of lawn4 ,calcium cyanide1 on being exposed to the atmosphere1 gives off hydrocyanic acid gas1 the evolution of the gas being governed by temperature and humidity4 ,calcium cyanide has replaced the old method of generating the gas by the action of sulphuric acid on potassium cyanide1 and is sold in the form of dusts or granules4 ,in the use of this material very great care is necessary1 since the gas is highly poisonous1 and also scorching of the foliage of plants results if atmospheric conditions are not considered carefully4 ,with ordinary care1 however1 calcium cyanide can be safely handled4 ,it is extremely effective against all kinds of pests1 and can be used to fumigate soil1 glass-houses1 or as a dust on plants in the open4 7c7 ,influence of ,natural ,enemies4 ,as stated in the first chapter1 plants are to be looked upon as the primary producers of life 7since all animals are directly or indirectly dependent upon them71 and the animals as the consumers4 ,many of the latter are destructive to crops grown by man1 and become pests1 but others1 fortunately1 exist upon these pests1 and are classed as beneficial animals2 it is the purpose of this section to deal with the more important of these from a horticultural viewpoint4 ,in ,new ,zealand such beneficial animals are insects1 birds1 and the hedgehog4 ,insects4 ,there is a wide range of insects that live at the expense of their fellows1 and without these plant production would be impossible1 either by ,nature or by man4 ,these so-called beneficial insects or parasites are the greatest factor in maintaining within reasonable bounds the insects that destroy vegetation2 they are of much greater value in this respect than birds4 ,in recent times the utilising of beneficial insects as a means of pest control has developed as one of the most important branches of entomological research4 ,from a general viewpoint1 the beneficial insects are to be found mainly among the groups1 including wasps1 beetles1 flies 7two-winged insects7 and lace-wings4 ,the following are some examples3-- ,common examples of parasitic insects are the ichneumon wasps 7,fig4 #ad;a71 chalcid wasps 7,fig4 #ad;b71 and ensign wasps1 the first being the most conspicuous1 the others less so owing to the minute size of many of them4 ,a characteristic feature of these forms is the stalk-like attachment of the abdomen to the thorax and the sting-like ovipositor of the female1 which may be of short or moderate length1 sometimes projecting as a tail-like appendage beyond the end of the abdomen4 ,parasites deposit their eggs either upon or within the body of their victims or hosts1 which are eventually destroyed by the larv hatching from the parasites' eggs4 ,destructive caterpillars and their pup1 and also aphides1 are attacked by these wasp-like parasites1 which in many cases restrict their depredations to one or a limited number of host species1 while others are more general in their selection4 ,another group1 the predaceous wasps1 should be mentioned here4 ,these insects in the adult state are hunters1 and capture and paralyse by stinging such insects as caterpillars and flies1 as well as spiders1 which are stored in nests or cells for the nourishment of the predators' offspring4 ,important natural enemies of aphides and young caterpillars are the hover-flies1 which can be easily recognised by their manner of flight4 ,they are two-winged insects 7,fig4 #ad;c71 and when on the wing hang motionless1 as if suspended by some unseen means1 to suddenly dart off with marvellous rapidity1 until they hang motionless as before4 ,these flies lay their eggs upon the foliage of plants infested by aphids or caterpillars1 and from these eggs legless and headless larv emerge 7,fig4 #ad;d71 and commence to search for and feed upon their victims4 ,another important group of two-winged flies is the tachinids4 ,they are rather robust1 usually very bristly 7,fig4 #ad;e72 they vary in size from that of a large blue-bottle to comparatively minute forms4 ,the tachinids lay their eggs either upon their hosts or on the food plants of the latter1 where they can be swallowed2 some tachinids give birth to living larv1 which crawl about in search of their victims4 ,among the beneficial beetles are the well-known ladybirds 7,fig4 #ad;f72 they are mostly oval in outline1 dome-shaped above and flat below1 while many of them are spotted by yellow1 red1 or white in a characteristic manner1 though others are of one uniform colour4 ,the eggs are laid on plants infested by the aphides and scale insects upon which the beetles and their larv 7,fig4 #ad;g7 feed4 ,there are other kinds of beetles of importance as predators1 such as the common tiger-beetle1 but they are not especially selective in their types of victims4 ,a very valuable group of insects includes the lace-wings or aphis-lions4 ,the adult insects 7,fig4 #ad;h7 carry the seemingly over-large lace-veined wings roof-like over the small body2 the larv are alligator-like 7,fig4 #ad;i71 and possess a pair of caliper-shaped jaws1 by means of which they capture their prey4 ,the eggs are laid directly on plants or are attached at the end of long stalks4 ,birds4 ,it is generally recognised that birds are a very important aid in keeping destructive insects in check1 though it is well-known that a great deal of damage can be done by these animals4 ,without a systematic study of the stomach contents of birds1 it is not possible to decide when a species is beneficial or injurious1 and in ,new ,zealand no such study has been made2 practically all the information we have is based on field observations1 which are1 unfortunately1 influenced largely by the outlook of the observer1 and are thus misleading4 ,though some species subsist for the most part on insects1 most land-birds have a mixed diet of vegetable and animal food1 but they specialise on an insect diet when rearing their young and when moulting4 ,illustration3 ,,figure #ad4 7a7 ,an ichneumon 7natural size #a-a_/d in72 7b7 a chalcid 7natural size #a-be in72 7c7 a hoverfly 7natural size #a_/h in72 7d7 hoverfly larva 7natural size #a_/d in72 7e7 a tachinid fly 7natural size #a_/d in72 7f7 a ladybird beetle 7natural size #a_/e in72 7g7 ladybird larva 7natural size #a_/d in72 7h7 lacewing 7natural size #a_/d in72 7i7 lacewing larva 7natural size #a_/e in74 ,based on the nature of their diet1 birds fall into three principal groups3 7#a7 those feeding almost solely upon seeds and fruits2 7#b7 insectivorous birds feeding on insects and other animals2 and 7#c7 the omnivorous species feeding both on insects and vegetable matter4 ,the seed-feeding birds are a potential menace to the agriculturist1 though in ,new ,zealand the native species are fundamental to the well-being of the native forests2 the insectivorous birds are obviously beneficial1 though they devour both destructive and useful insects2 while the omnivorous birds may be either useful or harmful1 according to the circumstances4 ,it should be remembered that1 no matter what the food of the adult bird may be1 most species give their young a diet of insects or other animal matter4 ,when it is realised that the weight of nestling birds increases from one-fifth to one-half each day1 requiring at times more than half the weight of the nestling in food1 one can better visualise the enormous quantities of insects daily destroyed for this purpose4 ,consider the common house sparrow1 which is usually condemned3 an analysis of the nestling diet has shown that it consisted of #dj per cent4 grain and #fj per cent4 insects and related forms1 while that of the adult comprised #ge per cent4 grain and #be per cent4 insects1 etc4 ,to summarise the situation1 it may be said that1 on the whole1 enormous numbers of insects are destroyed by birds each year1 and1 unless allowed to become abnormally abundant1 the benefit derived from birds outweighs the damage they may cause4 ,hedgehog4 ,the hedgehog was first introduced by the ,canterbury ,acclimatisation ,society in #ahgj1 and later by other societies and private individuals4 ,the animal is now very abundant in many parts of the ,dominion4 ,though condemned and destroyed by some people1 who consider it a menace to eggs1 chickens and even vegetables1 the hedgehog is really a very useful animal1 in that1 being a night prowler itself1 it destroys numerous nocturnal pests1 such as slugs and snails1 earwigs1 grass caterpillars and cut-worms4 ,the hedgehog1 on the approach of winter1 constructs a nest in some suitable place1 where it becomes torpid and hibernates4 ,on the advent of spring1 it becomes active once more1 and during summer produces a litter of four young2 a second litter is sometimes produced in the autumn4 ,,index4 ,page ,acacia1 #cb1 #ch ,agrotis ypsilon1 #eb ,alg1 #ad1 #ae ,almond1 #ce1 #ch1 #fd ,amaryllis1 #ff ,american blight1 #dg ,amb1 #ae ,anguillulina dipsaci1 #gb ,animal ,kingdom1 ,divisions of1 #h ,aphelinus fuscipennis1 #dj ,aphelinus mali1 #dg ,aphelinus mytilaspidis1 #ch1 #dj ,aphides1 #db ,aphis-lion1 #bh1 #gh ,aphis persic-niger1 #dd ,apple1 #cd1 #ce1 #cg1 #ch1 #dj1 #da1 #dg1 #dh1 #fa1 #fd1 #fg ,apple leaf-hopper1 #dh ,apple leaf-roller1 #ea ,apple mealy-bug1 #cd ,apple mussel-scale1 #cj1 #cg ,apple red-mite1 #eg ,apricot1 #ce1 #cf1 #ch ,army-worms1 #ed ,arsenate of lead1 #gf ,asexual1 #db ,ash1 #ch ,asparagus1 #cf ,aspidiotus heder1 #dj ,aspidiotus perniciosus1 #ch ,asterolecanium variolosum1 #cg ,austrian pine1 #df ,bacteria1 #ad1 #ae ,bag-moth1 #ef ,baker's mealy-bug1 #ce ,beet eelworm1 #gb ,beetles1 #ef ,begonia1 #cd ,beneficial insects1 #gg1 #gh ,birds1 #gi ,blackberry1 #cf1 #da ,blackbird1 #ce ,black cherry-aphis1 #dd ,black-currant1 #cf1 #dd ,black-leaf #dj1 #gf ,black peach-aphis1 #dd ,black scale1 #dj ,blister-mites1 #gj ,blue-gum1 #ei ,borers1 round-headed1 #fd ,breathing systems of insects1 #ba ,brevicoryne brassic1 #de ,briar1 #da ,bronze beetle1 #eh ,broods of insects1 #bb ,broom1 #eb ,brown-beetle1 #eh ,brown-mite1 #fh ,brussels sprouts1 #de ,bryobia prtiosa1 #fh ,bulb-eelworm1 #gb ,bulb-mite1 #fh ,bulb or ,narcissus flies1 #ff ,cabbage1 #de1 #dh1 #ee ,cabbage aphis1 #de ,cabbage green-fly1 #de ,cabbage-tree1 #ef ,cabbage-tree moth1 #ef ,cabbage-tree scales1 #ch ,cabbage white butterfly1 #ee ,calcium cyanide1 #gf ,caliora limacina1 #ei ,camellia1 #ce1 #cf1 #cg1 #dj ,camellia scale1 #cg ,carbon-bisulphide1 #gf ,caterpillars1 #ea ,caterpillars in lawns1 #fe ,cauliflower1 #de1 #ee ,cecidomyia oleari1 #fj ,cereals1 #ed ,chalcid wasps1 #gh ,chemicals1 #ge ,chermes pini1 #df ,cherry1 #ch1 #dd1 #ei ,cherry-aphis1 black1 #dd ,cherry slug1 #ei ,chitin1 #ag ,chrysalis1 #be ,chrysanthemum1 #fd ,chrysomphalus aurantii1 #dj ,chrysomphalus rossi1 #dj ,cicada1 #bh ,cineraria1 #bd1 #cd1 #ef1 #fd ,citrophilus mealy-bug1 #cd ,citrus1 #cb1 #ce1 #cf1 #dj1 #fd1 #fg ,click-beetles1 #fe ,clover1 #eb ,coccids1 #bi ,coccus hesperidum1 #cf ,cockchafers1 #eg ,cockroach1 #ag1 #bg ,cocoon1 #be ,codlin moth1 #fa ,comstock's mealy-bug1 #ce ,contact sprays and dusts1 #gf ,convolvulus1 #ed ,coprosma1 #dj ,cornicles1 #db ,cottony-cushion scale1 #cj1 #cb ,crayfish1 #ag ,crickets1 #bg1 #ea ,crocus1 #fh ,crop rotation1 #ge ,cruciferous crops1 #de ,cryptolmus ladybird1 #cd ,cryptolmus montrouzieri1 #cd ,curl-grubs1 #eh ,currant1 #cg1 #ch1 #fa1 #fh ,currant clear-wing borer1 #fa ,cuticle1 #ag ,cut-worms1 #eb ,cydia pomonella1 #fa ,daffodil1 #gb ,development of insects1 #bb ,diamond-backed moth1 #eb ,digestive system of insects1 #ba ,douglas fir1 #cb1 #df ,dusts1 #ge ,earthworms1 #ae ,earwig1 #bg1 #ej ,easter lily1 #fh ,eelworms1 #h1 #gb ,eggs of insects1 #bb ,elder1 #ce ,eleagnus1 #cg ,elm1 #ch1 #dg ,elm-leaf aphis1 #db1 #dg ,elytra1 #eh ,ensign wasps1 #gh ,eriococcus coriaceus1 #ce ,eriophyes pyri1 #gj ,eriosoma lanigerum1 #dg ,eucalypts1 #ce1 #ei ,eucalyptus tortoise beetle1 #ei ,eucolaspis brunneus1 #eh ,eulecanium berberidis1 #cg ,eulecanium corni1 #cf ,eumerus strigatus1 #ff ,euonymus1 #ce1 #cg1 #dj ,european earwig1 #ej ,european red-mite1 #fg ,fantail1 #ce ,ferns1 #cd1 #cf ,fig1 #cd1 #ce1 #cf1 #dj ,flax1 ,new ,zealand1 #ch ,flea-beetles1 #eh ,forficula auricularia1 #ej ,fruit lecanium scale1 #cf ,fumigants1 #gf ,fungi1 #ad1 #ae ,galls1 #db ,galtonia1 #ff ,gladiolus1 #gb ,gnorimoschema plsiosema1 #fb ,goat-willow1 #fd ,golden oak-scale1 #cg ,gonipterus scutellatus1 #ei ,gooseberry1 #ce1 #cf1 #cg1 #ch1 #fd ,gorse1 #cb ,grape louse1 #df ,grape phylloxera1 #df ,grape-vine1 #cd1 #ce1 #cf1 #cg1 #dj1 #df1 #ea1 #fg ,grass caterpillars1 #fe ,grasses1 #fd1 #fe ,grass-grubs1 #eg1 #fd ,grasshopper1 #ag1 #ea ,greasy cut-worms1 #eb ,green-fly of cabbage1 #de ,green-house thrips1 #di ,green-house white-fly1 #dh ,green manuka beetle1 #eh ,green peach-aphis1 #dd ,groundsel1 #bd1 #ef ,grub-proofing lawns1 #fd ,gum-tree scale1 #ce ,gum-tree weevil1 #ei ,habranthus1 #ff ,habrolepis dalmanni1 #cg ,hawk moth1 #ed ,hawthorn1 #cg1 #ch1 #ei1 #fg ,hedgehog1 #hj ,heliothrips hmorrhoidalis1 #bc ,hemispherical scale1 #cf ,heterodera radicola1 #gc ,heterodera schachtii1 #gb ,hibernation1 #bc ,holly1 #ce1 #cf ,honey-bee1 #ai ,honey-dew1 #bi1 #db ,honey-tubes1 #db ,hop1 #fh ,horse chestnut1 #ce ,hover-flies1 #ff1 #gh ,hyacinth1 #ff1 #fh1 #gb ,hydrangea1 #ce ,hydrocyanic-acid gas1 #gg ,hypopus1 #fh ,icerya purchasi1 #cb ,ichneumon wasps1 #gh ,importation of pests1 #gd ,insects1 proportion of1 #g ,insignis pine1 #df1 #ea ,invertebrates1 #g ,iris1 #ce ,ivy1 #ce1 #cf1 #dj ,japonica1 #cf ,karaka1 #dj ,kerosene1 #gf ,kowhai1 #eb ,kowhai moth1 #eb ,kumara1 #ed ,lace-wing1 #cd1 #gh ,ladybird beetles1 #gh ,larch1 #df ,larger narcissus fly1 #ff ,larva1 #bd ,laurel1 #ce1 #cf ,lawns1 #fd1 #fe ,lead arsenate1 #gf ,leaf-hoppers1 #dh ,leaf-mining flies1 #fd ,leaf-rollers1 #ea ,leech1 #ei ,lemon1 #ce1 #dj ,lepidosaphes ulmi1 #cg ,lepisma saccharina1 #bf ,lettuce1 #ee ,leucaspis cordylinidis1 #ch ,leucaspis stricta1 #ch ,leucojum1 #ff ,life-cycle of insects1 #bb ,lime-sulphur1 #gf ,loganberry1 #da ,long-horned beetles1 #fd ,long-tailed mealy-bug1 #cd ,lupins1 #eb ,macrosiphum ros1 #dg ,magpie-moth1 #bd1 #ee ,management of garden1 #gd ,manure1 #gd ,mealy-bugs1 #bi1 #cj1 #cb1 #cd ,mealy-wings1 #dc ,mecyna maorialis1 #eb ,merodon equestris1 #ff ,metamorphosis1 #bd ,micromus tasmani1 #bh1 #cd ,millepedes1 #ga ,mites1 #fg ,moulting1 #bb ,mouth appendages of insects1 #ai ,mulberry1 #ce1 #cf ,mussel scale of apple1 #cj1 #cg ,mustard1 #dd1 #de1 #dh1 #eb ,myrtle1 #cf ,myzus cerasi1 #dd ,narcissus1 #ff1 #fh1 #gb ,narcissus flies1 #ff ,natural enemies1 #gg ,nectarine1 #cf1 #dd ,nervous systems of insects1 #ba ,nicotine-sulphate1 #gf ,northern ,spy1 #dg ,novius cardinalis1 #cb ,nyctemera annulata1 #bd1 #ee ,oak1 #cg1 #ea ,oak-scale1 #cg ,odontria zealandica1 #eg1 #fd ,oeceticus omnivorus1 #ef ,oleander1 #cd1 #ce1 #cf1 #dj ,oleander-scale1 #dj ,olearia forsteri1 #fj ,olearia gall-midge1 #fj ,olive-scale1 #cj1 #ce ,onion1 #ff ,orange1 #ce1 #dj1 #ea ,orange-scale1 #dj ,orchids1 #cf1 #dj ,orcus chalybus1 #cf1 #dj ,oviparous1 #db ,ovipositor1 #ba ,palms1 #cd1 #ce1 #cf1 #dj ,paratetranychus pilosus1 #fg ,paris green1 #gf ,paropsis dilatata1 #ei ,parthenogenetic1 #db ,passion vine1 #cd ,pastures1 #fd1 #fe ,peach1 #ce1 #cf1 #ch1 #dd1 #dh1 #ei ,peach-aphis1 black1 #dd ,peach-aphis1 green1 #dd ,pear1 #cd1 #ce1 #cf1 #cg1 #ch1 #dj1 #da1 #ej1 #ei1 #fj1 #fa1 #gj ,pear and cherry saw-fly1 #ei ,pear and cherry slug1 #ei ,pear-leaf blister mite1 #gj ,pear-midge1 #fj ,pelargonium1 #ea ,pemphigus populi-transversus1 #dh ,pepper-tree1 #ce ,perrisia pyri1 #fj ,persimmon1 #ce ,phormium1 #cd ,phthorima operculella1 #fb ,phylloxera vastatrix1 #df ,pieris rap1 #ee ,pine-tree chermes1 #df ,plant food1 #ab ,plant-lice1 #db ,plum1 #cd1 #ce1 #cf1 #ch1 #dj1 #dd1 #dh1 #ei ,plum-aphis1 #dh ,plutella maculipennis1 #eb ,pontania proxima1 #fj ,poplar1 #ce1 #cg1 #ch1 #dh1 #fd ,poplar ,gall-aphis1 #db1 #dh ,porina1 #fe ,potato1 #cd1 #fb1 #gb ,potato sickness1 #gb ,potato tuber-moth1 #fb ,predaceous wasps1 #gh ,privet1 #ch ,protozoa1 #h1 #ae ,pulvinaria camelicola1 #cg ,pupa1 #be ,puparium1 #be ,pyronota festiva1 #eh ,quince1 #ch1 #dj1 #da ,radish1 #ee ,ragwort1 #bd1 #ef ,rape1 #de1 #dh ,raspberry1 #cf1 #da1 #fg ,red currant1 #dd ,red oil1 #gf ,red orange-scale1 #dj ,red spider1 #fh ,rhizoglyphus hyacinthi1 #fh ,rhododendron1 #dg ,rhophalosiphum nymph1 #dh ,rhophalosiphum persic1 #dd ,root-knot eelworm of tomato1 #gc ,rose1 #ce1 #ch1 #dj1 #da1 #dg1 #ea1 #eh1 #fg ,rose-aphis1 #db1 #dg ,rotation of crops1 #ge ,round-headed borers1 #fd ,saissetia hemispherica1 #cf ,saissetia ole1 #ce ,san ,jos scale1 #cb1 #ch ,scale insects1 #bi ,scylla1 #ff ,seasonal history of insects1 #bb ,seeds1 damage to1 #fe1 #ff1 #ga ,sesia tipuliformis1 #fa ,shallot1 #ff ,shepherd's purse1 #dd1 #eb ,silver-fish1 #bf ,slugs1 #h1 #ga ,smaller narcissus fly1 #ff ,snails1 #h1 #ga ,soil fumigation1 #gf ,sphinx convolvuli1 #ed ,sphinx moth1 #ed ,spiders1 #h1 #fg ,sprays1 #ge ,springtails1 #ff ,spruce1 #df ,steam sterilisation1 #gd ,steel-blue ladybird1 #cf1 #dj ,stomach poisons1 #gf ,strawberry1 #fd1 #fh ,subterranean grass caterpillars1 #fe ,sulphur smudge1 #eh1 #fe ,syrphids1 #ff ,tachinids1 #gh ,tetranychus telarius1 #fh ,thrips1 #bg1 #dh ,thrush1 #ce ,tobacco1 #ed1 #gc ,tomato1 #dg1 #ed1 #fb1 #gc ,tomato root-knot eelworm1 #gc ,tomato stem-borer1 #fb ,tortoise beetle1 #ei ,tortrix postvittana1 #ea ,tree-lucerne1 #fd ,trialeurodes vaporariorum1 #dh ,tui1 #ce ,tulip1 #ff1 #fh ,turnip1 #de1 #dh ,turnip-fly1 #eg ,turtle-scale1 #cf ,typhlocyba australis1 #dh ,vallota1 #ff ,vegetable caterpillars1 #fe ,venusia verriculata1 #ef ,vertebrates1 #g ,violet1 #fh ,viviparous1 #db ,walnut1 #ce ,watercress1 #df1 #eb ,water lilies1 #dh ,wattle1 #cb1 #da ,wax-eye1 #ce ,weta1 #ag ,white butterfly1 #ee ,white-flies1 #dh ,willow1 #ce1 #cg1 #ch1 #fj1 #fh ,willow saw-fly1 #fj ,wings of insects1 #bj ,wireworms1 #fe ,wistaria1 #cd1 #ce1 #cf ,woodlice1 #h1 #gj ,woolly-aphis1 #db1 #dg ,woolly-bear1 #bd1 #ef