FLY 



2232 



FLY 



into pupae (plural of pupa, the intermediate 

 state), -and in from eight to fourteen days 

 emerge as mature flies. Led by its strong 

 sense of smell, the young fly hastens from its 



DEVELOPMENT OF A FLY 

 (a) Egg; (6) larva; (c) pupa; (d) mature 

 insect. 



filthy hatching place to the nearest food-supply 

 spot perhaps an imperfectly screened kitchen 

 or the baby's milk, where it begins to be indeed 

 a deadly enemy. 



Harm Done by Flies. Occasionally some 

 person objects that the fly is receiving more 

 than its share of censure, claiming that a little 

 stingless insect cannot be one of the most 

 dangerous things in the world; but doctors and 

 scientists are ready with facts to prove the 

 contrary. It is no longer a theory but a well- 

 established fact that flies cause many of the 

 cases of typhoid; that "summer complaint" 

 might well be called "fly complaint," so clearly 

 is it spread by flies; that tuberculosis and all 

 filth diseases are carried by it; that domestic 

 animals owe many of their diseases to its 

 agency in fact, that flies cost in Canada and 

 the United States hundreds of millions of dol- 

 lars and scores of thousands of lives every 

 year. 



How they accomplish all this is very evi- 

 dent, since their hairy legs are peculiarly well 

 fitted for carrying germs and filth particles 

 from their favorite breeding-haunts to food 

 often left exposed for them to walk upon. 

 More than 6,000,000 bacteria, it has been esti- 

 mated, can be carried by one fly on its body 

 as it flies from the manure pile or the spit- 

 toon or the sick room to the baby's lips or to 

 the sugar bowl. It is not chance that the fly 

 season coincides with the season of dangerous 

 intestinal diseases and, very largely, with the 

 typhoid season; it is a clear case of cause and 

 effect. 



Facing the Fly Problem. The average per- 

 son feels helpless and hopeless in facing the 

 question of what is to be done about it. 

 "There always have been flies, therefore there 

 always will be flies," is his opinion, despite any 



little efforts on his part. Serious, scientific 

 men have faced the problem in a sober-minded, 

 scientific manner, and have found ways and 

 means which, if generally adopted, would do 

 much toward ridding the world of this pest. 

 In agricultural communities, such favorable 

 breeding-grounds as manure heaps and open 

 swill barrels can be replaced by covered ma- 

 nure bins and screened-top barrels, and the 

 flies be kept down; cities and villages, how- 

 ever, may, with proper care, be flyless. 



Some of the remedies are easy to apply and 

 have been employed for many years. Windows 

 and doors may be screened and "sticky fly- 

 paper" may be placed to catch those which do 

 slip in; but this is not beginning at the source. 

 First of all, the fight must be carried out-of- 

 doors. "Why not," asked a thirteen-year-old 

 boy, who had become interested in the exter- 

 mination of flies, "put all the flies in jail and 



THE HOUSE FLY 

 Greatly enlarged. 



let ourselves out?" The annual cost of screen- 

 ing windows and doors, estimated for the 

 United States and Canada at $15,000,000, would, 

 if properly expended, make screens unnecessary. 

 Preventive Methods. The first step in a 

 definite campaign is to kill the winter fly the 

 occasional specimen that survives in a shel- 

 tered place and in the spring crawls out to bask 

 and gain strength in the sunshine. Kill it 

 without pity it may be that thereby the world 

 is being rid of countless millions of summer 

 flies. Until these winter flies have obtained 

 abundant food they cannot lay eggs, and as 

 they are extremely hungry they are easier to 



