t-LlES AND OTHER HOUSEHOLD INSECTS I3 



prising that this insect should become extremely abundant by mid- 

 summer. . It has been estimated that 1200 house flies might be bred 

 from a pound of manure, and at this rate a good load would pro- 

 duce two and one half million. Fortunately, breeding is confined to 

 the warmer months, only a few flies wintering in houses in a more 

 or less dormant condition. 



Ordinarily, flies do not travel a great distance and, in most in- 

 stances, probably breed within 300 to 500 feet of places where they 

 are extremely abundant. Butcher carts, grocery wagons and elec- 

 tric or steam cars carrying more or less exposed meat and other 

 supplies attractive to flies, may become important agents in the dis- 

 semination of disease, since it is only necessary for these vehicles 

 to load where conditions are favorable for fly infection and we 

 may have a mysterious outbreak of disease at some distance from 

 the source of trouble. 



Natural enemies. The house fly, though so abundant, is subject 

 to attack by various natural enemies. One of the most common is 

 a fungous disease known asEmpusa muscae which is occa- 

 sionally responsible for the death of many flies, particularly toward 

 the end of summer. It is not uncommon to find a few individuals 

 affected by this disease every year. A small, reddish mite may be 

 occasionally found attached to flies, seriously weakening the host. 

 There are, in addition, wasps and spiders which prey upon flies 

 and undoubtedly are of considerable service though they are very 

 rarely sufliciently abundant to materially reduce the numbers of 

 this pest. Another interesting enemy of the house fly is known as 

 the house centipede,^ a harmless species which, in recent years, has 

 become well established in many houses in New York State. It is 

 credited with preying on house flies, cockroaches and presumably 

 other insect inhabitants of dwellings. 



Sanitary measures. The first essential is to prevent the spread 

 of disease by the prompt disinfection of all discharges, both fluid 

 and solid, from typhoid and other fever patients, thus preventing 

 so far as individual cases are concerned, the possibility of fly in- 

 fection. Such treatment should include all affections where there 

 is even a remote possibility of insects or other agents carr>'ing dis- 

 ease from one person to another. A very cheap and effective dis- 

 infectant, according to Dr Veeder, is a strong solution of the 

 common blue vitriol or sulfate of copper, a few pounds being suf- 

 ficient for a hogsheadful of disinfectant. 



^Scutigera forceps Raf. 



