,u4 ,s4 ,,department ,,of ,,agriculture ,,farmers' ,,bulletin ,no4 #adjh ,the ,,house ,,fly ,,and ,,how ,,to ,,suppress ,,it ,illustration3 fly ,illustration3 ,,usda seal ,the presence of flies is an indication of uncleanliness1 insanitary conditions1 and improper disposal of substances in which they breed4 ,they are not only annoying2 they are actually dangerous to health1 because they may carry disease germs to exposed foods4 ,it is therefore important to know where and how they breed1 and to apply such knowledge in combating them4 ,this bulletin gives information on this subject4 ,besides giving directions for ridding the house of flies by the use of screens1 fly papers1 poisons1 and flytraps1 it lays especial emphasis on the explanation of methods of eliminating breeding places and preventing the breeding of flies4 ,this bulletin supersedes ,farmers' ,bulletin #hea4 ,washington1 ,d4 ,c4 ,issued ,april1 #aibe2 revised ,november1 #aibf ,,the ,,house ,,fly#a ,,and ,,how ,,to ,,suppress ,,it4 ,by ,l4 ,o4 ,,howard1 ,chief of the ,bureau of ,entomology1 and ,f4 ,c4 ,,bishopp1 ,entomologist4 99 99 99 99 99 ,,contents4 ,page4 ,kinds of flies found in houses #a ,where the true house fly lays its eggs #b ,how the house fly passes the winter #f ,carriage of disease by the house fly #f ,excluding and capturing flies #g ,the use of screens #g ,fly papers and poisons #h ,fly sprays #h ,flytraps #i ,preventing the breeding of flies #i ,construction and care of stables #i ,fly-tight manure pits #aj ,frequency with which manure should be removed in cities and towns #aj ,health office regulations for control of house flies in cities #aj ,disposal of manure in rural and suburban districts #aa ,chemical treatment of manure to destroy fly maggots #ab ,maggot trap for destruction of fly larvae from horse manure #ac ,compact heaping of manure #ae ,garbage disposal and treatment of miscellaneous breeding places #ae ,sewage disposal in relation to the prevention of fly-borne diseases #ae ,what communities can do to eliminate the house fly #af 99 99 99 99 99 ,,kinds ,,of ,,flies ,,found ,,in ,,houses4 ,several species of flies are found commonly in houses4 ,some of them so closely resemble the true house fly that it requires very careful observation to distinguish them from it4 ,one of these is the biting stable fly#b 7fig4 #a74 ,it occurs frequently in houses and differs from the house fly in the important particular that its mouth parts are formed for piercing the skin4 ,this fly is so often mistaken for the house fly that most people think that the house fly can bite4 ,another frequent visitant of houses1 particularly in the spring and fall1 is the cluster fly4#c ,it is somewhat larger than the house fly1 and is distinguished by its covering of fine yellowish hairs4 ,occasionally this fly occurs in houses in such numbers as to cause great annoyance4 ,it gets its name of cluster fly from its habit of collecting in compact groups or clusters in protected corners during cold periods4 ,several species of metallic greenish or bluish flies also are found occasionally in houses4 ,these include a blue-bottle fly1#d the black blowflies1#e and the green-bottle 7fig4 #b7 flies4#f ,they breed in decaying animal matter4 ,footnote #a3 ,musca domestica ,l4 ,footnote #b3 ,stomoxys calcitrans ,l4 ,footnote #c3 ,pollenia rudis ,fab4 ,footnote #d3 ,calliphora erythrocephala ,meig4 ,footnote #e3 ,phormia regina ,meig4 and ,p4 terrae-novae ,desv4 ,footnote #f3 ,lucilia caesar ,l41 ,l4 sericata ,meig41 and other species of the genus4 ,there is still another species1 smaller than any of those so far mentioned1 which is sometimes called the lesser house fly4#g ,this insect is distinguished from the ordinary house fly by its paler and more pointed body4 ,the male1 which is commoner than the female1 has large pale patches at the base of the abdomen1 which are translucent when the fly is seen on the window pane4 ,these little flies are not the young of the larger flies4 ,flies do not grow after the wings have once expanded and dried4 ,footnote #g3 ,fannia canicularis ,l4 ,illustration3 ,,fig4 #a4--,the stable fly4 ,much enlarged4 ,illustration3 ,,fig4 #b4--,one of the green-bottle flies 7,lucilia caesar74 ,much enlarged4 ,in late summer and autumn many specimens of a small fruit fly1 known as the vinegar fly1#h make their appearance1 attracted by the odor of overripe fruit4 ,all of these species1 however1 are greatly dwarfed in numbers by the common house fly4 ,in #aijj the senior author made collections of the flies in dining rooms in different parts of the country1 and found that the true house fly made up #ih4h per cent of the whole number captured4 ,the remainder comprised various species1 including those mentioned above4 ,footnote #h3 ,drosophila ampelophila ,loew4 ,illustration3 ,fig4 #c4--,the true house fly4 ,enlarged4 ,,where ,,the ,,true ,,house ,,fly ,,lays ,,its ,,eggs4 ,the true house fly 7fig4 #c71 which is found in nearly all parts of the world1 is a medium-sized fly with four black stripes on the back and a sharp elbow in one of the veins of the wings4 ,the house fly can not bite1 its mouth parts being spread out at the tip for sucking up liquid substances4 ,the eggs 7figs4 #d1 #e7 are laid upon horse manure4 ,this substance seems to be its favorite larval food4 ,it will breed also in human excrement1 and because of this habit it is very dangerous to the health of human beings1 carrying as it does the germs of intestinal diseases1 such as typhoid fever and cholera1 from the excreta to food supplies4 ,it has also been found to breed freely in hog manure1 in considerable numbers in chicken dung1 and to some extent in cow manure4 ,indeed1 it will lay its eggs on a great variety of decaying vegetable and animal materials1 but of the flies that infest dwelling houses1 both in cities and on farms1 a vast proportion come from horse manure4 ,illustration3 ,,fig4 #d4--;,eggs of the house fly4 ,about natural size4 7,newstead47 ,it often happens1 however1 that this fly is very abundant in localities where little or no horse manure is found1 and in such cases it breeds in other manure1 such as chicken manure in backyard poultry lots1 or in slops or fermenting vegetable material1 such as spent hops1 moist bran1 ensilage1 or rotting potatoes4 ,accumulations of organic material on the dumping grounds of towns and cities often produce flies in great numbers4 ,illustration3 ,,fig4 #e4--;,eggs of the house fly4 ,highly magnified4 7,newstead47 ,the house fly begins laying eggs in from #b #a_/b to #bj days after emerging1 the time interval depending to a large extent upon temperature1 humidity1 and character and abundance of food4 ,the number of eggs laid by an individual fly at one time ranges from #abj to #aei and a single female will usually lay two and sometimes four such batches4 ,dunn has recently reported that in ,panama a fly may deposit as many as #b1cfg eggs in #ba batches1 and sometimes an interval of only #cf hours may occur between the deposition of large batches of eggs4 ,the enormous numbers in which the insects occur are thus plainly accounted for1 especially when the abundance and universal occurrence of appropriate larval food is considered4 ,the eggs are deposited below the surface in the cracks and interstices of the manure1 several females usually depositing in one spot1 so that the eggs commonly are found in large clusters 7fig4 #d7 in selected places near the top of the pile1 where a high degree of heat is maintained by the fermentation below4 ,the second batch of eggs is laid from #h to #aj days after the first4 ,the eggs usually hatch in less than #bd hours4 ,under the most favorable conditions of temperature and moisture the egg state may last hardly more than #h hours4 ,the maggots which issue from the eggs are very small and transparent4 ,they grow rapidly1 completing the growth of the larva stage in three days under the most favorable conditions1 although this stage usually lasts from #d to #g days4 ,the larval period may be prolonged greatly by low temperature or by dryness or scarcity of the larval food4 ,as the larvae 7fig4 #f7 attain full size they gradually assume a creamy white color4 ,a few hours before pupation they become very restless and migrate from their feeding ground in search of a favorable place in which to pass the pupa stage4 ,they will often congregate at the edges of manure piles near the ground or burrow into the soil beneath1 or they may crawl considerable distances away from the pile to pupate in the ground or in loose material under the edges of stones1 boards1 etc4 ,illustration3 ,,fig4 #f4--,larvae1 or maggots1 of the house fly4 ,about natural size4 7,newstead47 ,the pupae 7fig #g71 or sleepers1 are more or less barrel shaped and dark brown in color4 ,in midsummer this stage usually lasts from #c to #f days4 ,the pupa stage is easily affected by temperature changes and may be prolonged during hibernation for as long as #d or #e months4 ,numerous rearing experiments in various parts of the country have shown that the shortest time between the deposition of eggs and the emergence of the adult fly is #h days1 and #aj and #ab day records were very common4 ,the adult fly1 upon emerging from the puparium1 works its way upward through the soil or manure and upon reaching the air it crawls about while its wings expand and the body hardens and assumes its normal coloration4 ,in from #b #a_/b to #bj days1 as previously stated1 the female is ready to deposit eggs4 ,as in the case of other periods of its life history1 so the preoviposition period is prolonged considerably by the lower temperatures of spring and fall4 ,in midsummer1 with a developmental period of from #h to #aj days from egg to adult1 and a preoviposition period of from #c to #d days1 a new generation would be started every #aa to #ad days4 ,thus the climate of the ,district of ,columbia allows abundance of time for the development of from #aj to #ab generations every season4 ,illustration3 ,,fig4 #g4--,pupae of the house fly4 ,about natural size4 7,newstead47 ,flies usually remain near their breeding places if they have plenty of food1 but experiments recently made at ,dallas1 ,tex41 show that they may migrate considerable distances2 in fact1 house flies1 so marked that the particular individuals could be identified1 have been recaptured in traps as far as #ac miles from the place where they were liberated4 ,,how ,,the ,,house ,,fly ,,passes ,,the ,,winter4 ,the prevailing opinion that the house fly lives through the winter as an adult1 hiding in cracks and crevices of buildings1 etc41 appears to be erroneous4 ,under outdoor conditions house flies are killed during the first really cold nights1 that is1 when the temperature falls to about #ae deg4 or #aj deg4 ,f4 ,in rooms and similar places protected from winds and partially heated during the winter flies have been kept alive in cages for long periods1 but they never lived through the entire winter4 ,in longevity experiments one record of #gj days and another of #ia days was obtained4 ,no uncaged house flies were found during three seasons' observations in unheated and only partially heated attics1 stables1 unused rooms1 etc41 where favorable temperature conditions prevailed4 ,the common occurrence in such places of the cluster fly and a few other species1 which may be easily mistaken for the house fly1 is responsible for the prevailing belief as to the way the house fly overwinters4 ,there is therefore no reliable evidence whatever that adult house flies emerging during ,october and ,november pass the winter and are able to deposit their eggs the following spring1 although they may continue active in heated buildings until nearly the end of ,january4 ,on the other hand1 there is evidence that house flies pass the winter as larvae and pupae1 and that they sometimes breed continuously throughout the winter4 ,in experiments at both ,dallas1 ,tex41 and ,bethesda1 ,md41 house flies have been found emerging during ,april from heavily infested manure heaps which had been set out and covered with cages during the preceding autumn4 ,in the ,southern ,states1 during warm periods in midwinter1 house flies may emerge and become somewhat troublesome2 they frequently lay eggs on warm days4 ,the second way in which the house fly may pass the winter is by continuous breeding4 ,house flies congregate in heated rooms with the approach of the winter season4 ,if no food or breeding materials are present they eventually die4 ,however1 where they have access to both food and suitable substances for egg laying they will continue breeding just as they do outdoors during the summer4 ,even in very cold climates there are undoubtedly many places1 especially in cities1 where house flies would have opportunity to pass the winter in this manner4 ,,carriage ,,of ,,disease ,,by ,,the ,,house ,,fly4 ,the body of the house fly is covered thickly with hairs and bristles of varying lengths1 and this is especially true of the legs4 ,thus1 when it crawls over infected material it readily becomes loaded with germs1 and subsequent visits to human foods result in their contamination4 ,even more dangerous than the transference of germs on the legs and body of the fly is the fact that bacteria are found in greater numbers and live longer in its alimentary canal4 ,these germs are voided1 not only in the excrement of the fly1 but also in small droplets of regurgitated matter which have been called vomit spots4 ,when we realize that flies frequent and feed upon the most filthy substances 7it may be the excreta of typhoid or dysentery patients or the discharges of one suffering from tuberculosis71 and that subsequently they may contaminate human foods with their feet or excreta or vomit spots1 the necessity and importance of house-fly control is clear4 ,in army camps1 in mining camps1 and in great public works1 where large numbers of men are brought together for a longer or shorter time1 there is seldom the proper care of excreta1 and the carriage of typhoid germs from the latrines and privies to food by flies is common and often results in epidemics of typhoid fever4 ,and such carriage of typhoid is by no means confined to great temporary camps4 ,in farmhouses in small communities1 and even in badly cared for portions of large cities1 typhoid germs are carried from excrement to food by flies1 and the proper supervision and treatment of the breeding places of the house fly become most important elements in the prevention of typhoid4 ,in the same way other intestinal germ diseases1 such as ,asiatic cholera1 dysentery1 enteritis 7inflammation of the intestine71 and infantile diarrhea1 are all so carried4 ,there is strong circumstantial evidence also that tuberculosis1 anthrax1 yaws1 ophthalmia1 smallpox1 tropical sore1 and the eggs of parasitic worms may be and are carried in this way4 ,in the case of over #cj different disease organisms and parasitic worms1 actual laboratory proof exists1 and where lacking is replaced by circumstantial evidence amounting almost to certainty4 ,,excluding ,,and ,,capturing ,,flies4 ,the principal effort to control this dangerous insect must be made at the source of supply--its breeding places4 ,absolute cleanliness and the removal or destruction of anything in which flies may breed are essential2 and this is something that can be done even in cities4 ,perhaps it can be done more easily in the cities than in villages1 on account of their greater police power and the lesser insistence on the rights of the individual4 ,once people are educated to the danger and learn to find the breeding places1 the rest will be easy4 ,in spite of what has just been said1 it is often necessary to catch or otherwise destroy adult flies1 or to protect food materials from contamination and persons from annoyance or danger2 hence the value of fly papers and poisons1 flytraps1 and insect screens4 ,,the ,,use ,,of ,,insect ,,screens4 ,a careful screening of windows and doors during the summer months1 with the supplementary use of sticky fly papers1 is a protective measure against house flies known to everyone4 ,as regards screening1 it is only necessary here to emphasize the importance of keeping food supplies screened or otherwise covered so that flies can gain no access to them4 ,this applies not only to homes but also to stores1 restaurants1 milk shops1 and the like4 ,screening1 of course1 will have no effect in decreasing the number of flies1 but at least it has the virtue of lessening the danger of contamination of food4 ,insect screens for doors and windows should be well made and must fit tightly1 otherwise they will not keep insects out4 ,it is equally important that they be made of good and durable screen cloth4 ,copper insect screen cloth1 although a little higher in price1 will prove more economical in the long run1 as it lasts many years4 ,if1 however1 the cost of copper screen cloth is objectionable1 steel screen cloth1 either painted or galvanized1 can be used4 ,painted steel screen cloth will last one or more years without repainting1 its durability depending upon the climate4 ,in humid regions1 of course1 it will rust more quickly than it will where the climate is dry4 ,the same may be said of galvanized steel insect screen cloth4 ,insect screen cloth made with #af meshes to the inch is recommended1 for #af-mesh screen cloth will keep out flies and most mosquitoes#i and other small insects which at times are found almost everywhere4 ,footnote #i3 ,where the yellow fever or dengue fever mosquito occurs1 #ah-mesh screen cloth 7or #af-mesh screen cloth made from extra heavy wire7 should be used4 ,,fly ,,papers ,,and ,,poisons4 ,illustration3 ,,fig4 #h4--;,conical hoop flytrap side view4 ,a1 ,hoops forming frame at bottom4 ,b1 ,hoops forming frame at top4 ,c1 ,top of trap made of barrel head4 ,d1 ,strips around door4 ,e1 ,door frame4 ,f1 ,screen on door4 ,g1 ,buttons holding door4 ,h1 ,screen on outside of trap4 ,i1 ,strips on side of trap between hoops4 ,j1 ,tips of these strips projecting to form legs4 ,k1 ,cone4 ,l1 ,united edges of screen forming cone4 ,m1 ,aperture at apex of cone4 7,bishopp47 ,the use of sticky fly papers to destroy flies that have gained access to houses is well known4 ,fly-poison preparations also are common4 ,many of the commercial fly poisons contain arsenic1 and their use in the household is attended with considerable danger1 especially to children4 ,this danger is less with the use of a weak solution of formalin4 ,a very effective fly poison is made by adding #c teaspoonfuls of the commercial formalin to a pint of milk or water sweetened with a little brown sugar4 ,a convenient way of exposing this poison is by partly filling an ordinary drinking glass with the solution4 ,a saucer or plate is then lined with white blotting paper cut the size of the dish and placed bottom up over the glass4 ,the whole is then quickly inverted and a small match stick placed under the edge of the glass4 ,as the solution evaporates from the paper more flows out from the glass and thus the supply is automatically renewed4 ,,fly ,,sprays4 ,sprays designed to destroy or repel house flies fill a certain need in connection with the house-fly problem4 ,no very satisfactory repellent substances for this insect have been found which are at the same time adaptable to general use about the home1 or places where foods are handled4 ,extracts of pyrethrum flowers are now generally available commercially1 and these give fairly good results in the destruction of house flies in buildings4 ,most of the sprays of pyrethrum extract contain kerosene oil as a carrier1 and undoubtedly the kerosene has much to do with the toxicity of the spray4 ,such materials are most applicable to buildings which become infested with flies and which can be readily closed up at night and the air within thoroughly saturated with the spray by means of an atomizer4 ,under such conditions the flies are rather quickly overcome by the spray and if a sufficient quantity is used they will not revive4 ,,flytraps4 ,flytraps may be used to advantage in decreasing the number of flies4 ,their use has been advocated not only because of the immediate results1 but because of the chances that the flies may be caught before they lay eggs1 and the number of future generations will be reduced greatly4 ,many types of flytraps are on the market4 ,as a rule the larger ones are the more effective4 ,anyone with a few tools can construct flytraps for a small part of the price of the ready-made ones4 ,a trap 7fig4 #h7 which is very effective in catching flies and is easily made1 durable1 and cheap1 may be made of four barrel hoops1 four laths1 a few strips of boxing1 and #h #a_/b lineal feet of screening1 #bd inches wide4 7,for greater details see ,farmers' ,bulletin #gcd47 ,the effectiveness of the traps will depend on the selection of baits4 ,a good bait for catching house flies is #a part of blackstrap molasses to #c parts of water1 after the mixture has been allowed to ferment for a day or two4 ,overripe or fermenting bananas crushed and placed in the bait pans give good results1 especially with milk added to them4 ,a mixture of equal parts brown sugar and curd of sour milk1 thoroughly moistened1 gives good results after it has been allowed to stand for three or four days4 ,,preventing ,,the ,,breeding ,,of ,,flies4 ,as previously stated1 fly papers1 poisons1 and traps are at best only temporary expedients4 ,the most logical method of abating the fly nuisance is the elimination or treatment of all breeding places4 ,it would appear from what is known of the life history and habits of the common house fly that it is perfectly feasible for cities and towns to reduce the numbers of this annoying and dangerous insect so greatly as to render it of comparatively slight account4 ,on farms also1 in dairies1 and under rural conditions generally1 much can and should be done to control the fly1 which here1 as elsewhere1 constitutes a very serious menace to health4 ,,construction ,,and ,,care ,,of ,,stables4 ,in formulating rules for the construction and care of stables and the disposal of manure the following points must be taken into consideration4 ,in the first place1 the ground of soil-floor stables may offer a suitable place for the development of fly larvae4 ,the larvae will migrate from the manure to the soil and continue their growth in the moist ground4 ,this takes place to some extent even when the manure is removed from the stables every day4 ,even wooden floors are not entirely satisfactory unless they are perfectly water-tight1 since larvae will crawl through the cracks and continue their development in the moist ground below4 ,water-tight floors of concrete or masonry1 therefore1 are desirable4 ,flies have been found to breed in surprising numbers in small accumulations of material in the corners of feed troughs and mangers1 and it is important that such places be kept clean4 ,,fly-,,tight ,,manure ,,pits4 ,the ,bureau of ,entomology for a number of years has advised that manure from horse stables be kept in fly-tight pits or bins4 ,such pits can be built in or attached to the stable so that manure can be easily thrown in at the time of cleaning and so constructed that the manure can be readily removed4 ,it is desirable that the manure be placed in these fly-proof receptacles as soon as possible after it is voided4 ,the essential point is that flies be prevented from reaching the manure1 and for this reason the pit or bin must be tightly constructed1 preferably of concrete1 and the lid kept closed except when the manure is being thrown in or removed4 ,the difficulty has been that manure often becomes infested before it is put into the container1 and flies frequently breed out before it is emptied and often escape through the cracks4 ,to obviate these difficulties a manure box or pit with a modified tent trap or cone trap attached is desirable4 ,in order to retain the fertilizing value of manure to the greatest extent it is advisable that air be excluded from it as much as possible and that it be protected from the leaching action of rains4 ,this being the case1 there is really no necessity for covering a large portion of the top of the box with a trap1 but merely to have holes large enough to attract flies to the light1 and to cover these holes with ordinary conical traps1 with the legs cut off1 so1 that the bottoms of the traps will fit closely to the box4 ,the same arrangement can be made where manure is kept in a pit4 ,if manure boxes or pits are kept fly tight they are satisfactory under farm or dairy conditions for the storage of manure during the busy season when it can not be hauled out daily4 ,,frequency ,,with ,,which ,,manure ,,should ,,be ,,removed ,,in ,,cities ,,and ,,towns4 ,in deciding the question as to how often manure should be removed in cities and towns1 it should be borne in mind that when the larvae have finished feeding they will often leave the manure and pupate in the ground below or crawl some distance away to pupate in debris under boards or stones and the like4 ,hence the manure should be removed before the larvae reach the migratory stage2 that is to say1 removal is necessary every three days1 and certainly not less frequently than twice a week during the summer months4 ,a series of orders issued in #aijf by the health department of the ,district of ,columbia1 on the authority of the ,commissioners of the ,district1 covers most of these points1 and these orders1 which may well serve as a model to other communities desiring to undertake similar measures1 may be briefly condensed as follows3 ,,health ,,office ,,regulations ,,for ,,control ,,of ,,house ,,flies ,,in ,,cities4 ,all stalls in which animals are kept shall have the surface of the ground covered with a water-tight floor4 ,every person occupying a building where domestic animals are kept shall maintain in connection therewith a bin or pit for the reception of manure and1 pending the removal from the premises of the manure from the animal or animals1 shall place such manure in said bin or pit4 ,this bin shall be so constructed as to exclude rain water and shall in all other respects be water-tight1 except as it may be connected with the public sewer4 ,it shall be provided with a suitable cover and constructed so as to prevent the ingress and egress of flies4 ,no person owning a stable shall keep any manure or permit any manure to be kept in or upon any portion of the premises other than the bin or pit described1 nor shall he allow any such bin or pit to be overfilled or needlessly uncovered4 ,horse manure may be kept tightly rammed into well-covered barrels for the purpose of removal in such barrels4 ,every person keeping manure in the more densely populated parts of the ,district shall cause all such manure to be removed from the premises at least twice every week between ,june #a and ,october #ca1 and at least once every week between ,november #a and ,may #ca of the following year4 ,no person shall remove or transport any manure over any public highway in any of the more densely populated parts of the ,district except in a tight vehicle1 which1 if not inclosed1 must be effectually covered with canvas1 so as to prevent the manure from being dropped4 ,no person shall deposit manure removed from the bins or pits within any of the more densely populated parts of the ,district without a permit from the health officer4 ,any person violating any of the provisions shall1 upon conviction thereof1 be punished by a fine of not more than #dj for each offense4 ,not only must horse stables be cared for1 but chicken yards1 piggeries1 and garbage receptacles as well4 ,in cities1 with better methods of disposal of garbage and with the lessening of the number of horses and horse stables consequent upon electric street railways1 bicycles1 and automobiles1 the time may come1 and before very long1 when window screens may be discarded4 ,,disposal ,,of ,,manure ,,in ,,rural ,,and ,,suburban ,,districts4 ,the control of flies in rural and suburban districts offers a much more difficult problem4 ,here it is often out of the question to remove all manure from the premises twice a week1 and the problem is to find some method of disposal or storage which will conserve the fertilizing value of the manure and at the same time prevent all flies from breeding1 or destroy such as do breed there4 ,with this idea in mind1 it has been recommended that stable manure be collected every morning and hauled out at once and spread rather thinly on the fields4 ,this procedure is advisable from the point of view of getting the maximum fertilizing value from the manure4 ,immediate spreading on the fields is said largely to prevent the loss of plant food which occurs when manure is allowed to stand in heaps for a long time4 ,this method will be effective in preventing the breeding of flies only if the manure is hauled out promptly every morning and spread thinly so that it will dry1 since it is unfavorable for fly development in desiccated condition4 ,the proper scattering of the manure on the fields is best and most easily and quickly accomplished by the use of a manure spreader1 and many dairies1 and even farms1 are practicing the daily distribution of manure in this way4 ,removal every three or four days will not be sufficient4 ,observations have shown that if manure becomes flyblown and the maggots attain a fairly good size before the manure is scattered on the fields1 they can continue their development and will pupate in the ground4 ,,chemical ,,treatment ,,of ,,manure ,,to ,,destroy ,,fly ,,maggots4 ,during the summer months1 when fly breeding is going on most actively1 the farmer is also busy and often can not spare the time to remove manure regularly4 ,the general practice1 therefore1 has been to keep the manure in heaps located1 as a rule1 very near the stables4 ,how can fly breeding be prevented in such accumulations8 ,as a result of recent investigations1 it is now possible to point out two methods which are practical and effective4 ,the first is the treatment of the manure pile with chemical substances which will kill the eggs and maggots of the house fly4 ,the ,bureau of ,entomology1 in cooperation with the ,bureau of ,chemistry and the ,bureau of ,plant ,industry1 has conducted a series of experiments in which a large number of chemicals were applied to infested manure and observations made1 not only on their efficiency in killing the maggots but also as to their effect on the chemical composition and bacterial flora of the manure4 ,the object was to find some cheap chemical which would be effective in destroying the fly larvae and at the same time would not reduce the fertilizing value of the manure4 ,,treatment ,,with ,,hellebore4 ,of the numerous substances tried1 the one which seems best to fulfill these conditions is powdered hellebore4#aj ,for the treatment of manure a water extract of the hellebore is prepared by adding #a_/b pound of the powder to every #aj gallons of water1 and after stirring it is allowed to stand #bd hours4 ,the mixture thus prepared is sprinkled over the manure at the rate of #aj gallons to every #h bushels 7#aj cubic feet7 of manure4 ,from the result of #ab experiments with manure piles treated under natural conditions it appears that such treatment results in the destruction of from #hh to #ii per cent of the fly larvae4 ,studies of treated manure indicated that its composition and rotting were not interfered with4 ,furthermore1 several field tests showed that there was no apparent injury to growing crops when fertilized with treated manure4 ,since the solution is somewhat poisonous it should not be left exposed where it might be drunk by livestock4 ,it is quite safe to say that chickens will not be injured by pecking at hellebore-treated manure4 ,this has been tested carefully4 ,hellebore can be obtained both in ground and powdered form1 but the powder gives the best results in the destruction of fly larvae4 ,footnote #aj3 ,veratrum viride or ,v4 aloum4 ,,treatment ,,with ,,powdered ,,borax4 ,another chemical found to be even more effective as a larvicide is powdered borax4 ,this substance is available in commercial form in all parts of the country4 ,it has the advantage of being comparatively nonpoisonous and noninflammable and is easily transported and handled4 ,the minimum amount necessary to kill fly larvae was found to be #j4fb pound per #h bushels of manure1 or about #a pound per #af cubic feet4 ,best results were obtained when the borax was applied in solution1 or when water was sprinkled on after the borax had been scattered evenly over the pile4 ,borax is not only effective in killing the larvae1 but when it comes in contact with the eggs it prevents them from hatching4 ,when applied at the rate of #a pound to #af cubic feet it was found to kill about #ij per cent of the larvae1 heavier applications killing from #ih to #ii per cent4 ,borax has no injurious effect on the chemical composition or rotting of the manure4 ,however1 when added in large quantities with manure to the soil it will cause considerable injury to growing plants4 ,a number of experiments have been conducted to determine the effect on crops of the use of manure treated with borax as herein recommended4 ,when applied at the rate of #ae tons per acre it appears that no injury as a rule will follow4 ,some crops are more sensitive to borax than others1 and also the tendency to injury appears to vary on different soils4 ,it is necessary1 therefore1 to repeat the warning issued in connection with a previous bulletin#aa on this subject1 that great care be exercised1 in the application of borax1 that the manure does not receive more than #a pound for every #af cubic feet1 and that not more than #ae tons of manure so treated are applied to the acre4 ,in view of the possible injury from the borax treatment as a result of carelessness in applying it1 or from other unforeseen conditions1 it is recommended that horse manure and other farmyard manures which are to be used as fertilizer be treated with hellebore4 ,borax1 on the other hand1 is such a good larvicide that it call be used with advantage on the ground of soil-floor stables1 in privies1 on refuse piles1 and on any accumulations of fermenting organic matter which are not to be used for fertilizing purposes4 ,footnote #aa3 ,department ,bulletin #aah1 ,u4 ,s4 ,department of ,agriculture1 p4 #be4 ,,treatment ,,with ,,calcium ,,cyanamid ,,and ,,acid ,,phosphate4 ,many experiments with mixtures of commercial fertilizers were tried to determine whether fly larvae would be killed by any substance the addition of which would increase the fertilizing value of the manure4 ,a mixture of calcium cyanamid and acid phosphate was found to possess considerable larvicidal action4 ,several experiments showed that #a_/b pound of calcium cyanamid plus #a_/b pound of acid phosphate to each bushel of manure give an apparent larvicidal action of #ih per cent4 ,the mixture in the form of a powder was scattered evenly over the surface and then wet down with water4 ,the use of this mixture adds to the manure two important elements1 nitrogen and phosphorus4 ,,maggot ,,trap ,,for ,,destruction ,,of ,,fly ,,larvae ,,from ,,horse ,,manure4 ,the second method of handling manure is one which does not require the application of chemicals4 ,it is based on the fact1 mentioned on page #d1 that the larvae of the house fly1 a few hours before they are ready to pupate1 show a strong tendency to migrate4 ,this migration takes place mostly at night1 and the larvae sometimes crawl considerable distances from the manure pile4 ,now it is possible by means of a very simple arrangement called a maggot trap to destroy fully #ii per cent of all maggots breeding in a given lot of manure4 ,a successful maggot trap which the ,maryland ,agricultural ,college constructed at the college barn is shown in ,figure #i4 ,the trap was designed by ,r4 ,h4 ,hutchison and constructed under his supervision4 ,the manure1 instead of being thrown on the ground1 is heaped carefully on a slatted platform1 which stands about #a foot high4 ,this particular platform measures #aj by #bj feet4 ,there are six #b by #d pieces running lengthwise #b feet apart4 ,across these are nailed #a-;inch strips with #a_/b to #a inch spaces between them4 ,the wooden platform stands on a concrete floor1 and a rim or wall of concrete #d inches high surrounds the floor4 ,the floor slopes a little toward one corner from which a pipe leads to a small cistern near by4 ,this pipe is plugged with a stopper of soft wood1 and the concrete floor is filled with water to a depth of #a inch in the shallowest part4 ,flies will lay their eggs on the manure as usual1 but the maggots1 when they have finished feeding and begin to migrate1 crawl out of the manure1 drop into the water below1 and are drowned4 ,each week the plug is removed from the pipe1 and all the maggots are washed into the cistern4 ,the floor is then cleaned of any solid particles by means of a long-handled stable broom or by a strong stream of water from a hose4 ,the pipe being again plugged1 the floor is again partly filled with water and the trap is ready for another week's catch4 ,a platform of this size will hold the manure accumulating from four horses during the period of four months1 or about #bj days' accumulation from #be horses1 if the heap is well built and made at least #e feet high4 ,illustration3 ,,fig4 #i4 ,a maggot trap for house-fly control4 ,view showing the concrete basin containing water in which larvae are drowned1 and the wooden platform on which manure is heaped4 7,hutchison47 ,experience with this maggot trap clearly indicates that best results can be secured if the manure is compactly heaped on the platform and kept thoroughly moistened4 ,it is best to apply a small amount of water each morning after the stable cleanings have been added to the pile4 ,it should be borne in mind that in order to make this trap a success the platform beneath the pile must be kept comparatively free of accumulations of manure1 and moisture applied regularly to drive the maggots out4 ,,compact ,,heaping ,,of ,,manure4 ,another method of disposing of manure has been recommended by ,english writers4 ,the manure is built up in a compact rectangular heap1 the sides of which are beaten hard with shovels4 ,the ground around the edges of the heap is made smooth and hard and loose straw is placed in small windrows around the manure pile about #a foot from the edge4 ,the exclusion of the air1 together with the high temperature and gases formed by fermentation1 tends to make the heap unfavorable for the development of fly larvae4 ,those which do happen to develop in the surface layers will migrate and pupate in the ring of straw around the heap1 where they are destroyed by burning4 ,,garbage ,,disposal ,,and ,,treatment ,,of ,,miscellaneous ,,breeding ,,places4 ,it is just as true under farm conditions as in cities that breeding places other than horse manure must be attended to4 ,garbage must be disposed of1 hog and poultry manure must be cared for1 and especially on dairy farms it is extremely important that every precaution be taken to prevent the contamination of milk by flies4 ,it is very desirable that all refuse possible1 accumulated from cities and towns1 be burned4 ,incineration has been practiced successfully by a number of towns and cities with populations of from #aj1jjj to #ae1jjj and over4 ,in larger cities provision should be made for burning carcasses as well as garbage and other refuse4 ,if city and town garbage is sold to hog feeders the municipal authorities should have control of the sanitary conditions about the feeding yards1 as there is great danger from fly breeding in such places if not kept clean4 ,,sewage ,,disposal ,,in ,,relation ,,to ,,the ,,prevention ,,of ,,fly-,,borne ,,diseases4 ,in the consideration of these measures we have not touched upon the remedies for house flies breeding in human excrement4 ,on account of the danger of the carriage of typhoid fever1 the dropping of human excrement in the open in cities or towns1 either in vacant lots or in dark alleyways1 should be made a misdemeanor1 and the same care should be taken by the sanitary authorities to remove or cover up such depositions as is taken in the removal of the bodies of dead animals4 ,for modern methods of sewage disposal adapted for farm use one should consult ,department of ,agriculture ,department ,bulletin ,no4 #eg4 ,in the absence of modern methods of sewage disposal1 absolutely sanitary privies are prime necessities1 whether in towns or on farms4 ,directions for building and caring for such privies will be found in ,farmers' ,bulletin #dfc and in ,yearbook ,separate #gab1 ,sewage ,disposal on the ,farm4 ,the box privy is always a nuisance from many points of view1 and is undoubtedly dangerous as a breeder of flies which may carry the germs of intestinal diseases4 ,the dry-earth treatment of privies is unsatisfactory4 ,no box privy should be permitted to exist unless it is thoroughly and regularly treated with some effective larvicide4 ,since the fecal matter in such privies is seldom used for fertilizing purposes it may well be treated liberally with borax4 ,the powdered borax may be scattered two or three times a week over the exposed surface so as to whiten it4 ,,what ,,communities ,,can ,,do ,,to ,,eliminate ,,the ,,house ,,fly4 ,antifly crusades have been very numerous in recent years1 and some have been noteworthy both in methods and in results4 ,however1 it will not be amiss here to emphasize the importance of concerted1 organized effort on the part of whole communities1 not only cities1 but suburban and rural neighborhoods as well4 ,by the most painstaking care one may prevent all fly breeding on his premises1 but it will avail him little if his neighbors are not equally careful4 ,some sort of cooperation is necessary4 ,one of the first and most important elements in any antifly crusade is a vigorous and continued educational campaign4 ,it has been the experience of those who have undertaken such crusades that people generally regard the fly as a somewhat harmless nuisance and that the first work of the campaign was to bring the people to a realization of the dangers from flies and the possibility of getting rid of them4 ,in the educational campaign every possible means of publicity can be employed1 including newspapers1 lectures1 moving pictures1 posters1 handbills1 cartoons1 instruction in schools1 etc4 ,the antifly crusade is a matter of public interest and should be supported by the community as a whole and engineered by the health officers4 ,but health officers can do little toward the necessary work of inspection and elimination without funds1 and therefore the support of the campaign must manifest itself in increased appropriations for public-health work4 ,very often it is lack of funds which prevents the health officers from taking the initiative in the antifly crusades1 and there must necessarily be much agitation and education before they can profitably take up the work4 ,right here lies a field for civic associations1 women's clubs1 boards of trade1 etc41 to exercise their best energy1 initiative1 and leadership4 ,,organization ,,of ,,the ,,united ,,states ,,department ,,of ,,agriculture ,,when ,,this ,,publication ,,was ,,last ,,printed ,secretary of ,agriculture ,,arthur ,m4 ,,hyde4 ,assistant ,secretary ,r4 ,w4 ,,dunlap4 ,director of ,scientific ,work ,a4 ,f4 ,,woods4 ,director of ,regulatory ,work ,,walter ,g4 ,,campbell4 ,director of ,extension ,work ,c4 ,w4 ,,warburton4 ,director of ,personnel and ,business ,administration ,w4 ,w4 ,,stockberger4 ,director of ,information ,m4 ,s4 ,,eisenhower4 ,solicitor ,e4 ,l4 ,,marshall4 ,bureau of ,agricultural ,economics ,,nils ,a4 ,,olsen1 ,chief4 ,bureau of ,agricultural ,engineering ,s4 ,h4 ,,mccrory1 ,chief4 ,bureau of ,animal ,industry ,,john ,r4 ,,mohler1 ,chief4 ,bureau of ,biological ,survey ,,paul ,g4 ,,redington1 ,chief4 ,bureau of ,chemistry and ,soils ,h4 ,g4 ,,knight1 ,chief4 ,office of ,cooperative ,extension ,work ,c4 ,b4 ,,smith1 ,chief4 ,bureau of ,dairy ,industry ,o4 ,e4 ,,reed1 ,chief4 ,bureau of ,entomology ,c4 ,l4 ,,marlatt1 ,chief4 ,office of ,experiment ,stations ,,james ,t4 ,,jardine1 ,chief4 ,food and ,drug ,administration ,,walter ,g4 ,,campbell1 ,director of ,regulatory ,work1 in ,charge4 ,forest ,service ,r4 ,y4 ,,stuart1 ,chief4 ,grain ,futures ,administration ,j4 ,w4 ,t4 ,,duvel1 ,chief4 ,bureau of ,home ,economics ,,louise ,,stanley1 ,chief4 ,library ,,claribel ,r4 ,,barnett1 ,librarian4 ,bureau of ,plant ,industry ,,william ,a4 ,,taylor1 ,chief4 ,bureau of ,plant ,quarantine ,,lee ,a4 ,,strong1 ,chief4 ,bureau of ,public ,roads ,,thomas ,h4 ,,macdonald1 ,chief4 ,weather ,bureau ,,charles ,f4 ,,marvin1 ,chief4 ,u4 ,s4 ,,government ,,printing ,,office3 #aich ,for sale by the ,superintendent of ,documents1 ,washington1 ,d4 ,c4 ,price #e cents ,transcriber's ,note3 ,footnotes #aj #aa renumbered to avoid the confusion generated by two footnote #i's4