2O NEW YORK STATE MUSEUM 



ing houses in large numbers and forming conspicuous clusters in 

 closets, unused rooms or other retreats. It is easily distinguished 

 by its somewhat larger size and the black thorax covered rather 

 thickly with tawny hairs which frequently incline to a grayish 

 shade. This insect is also known as the " buckwheat fly " because 

 of the frequent association between its occurrence and buckwheat. 

 Investigations in Europe and this country have shown that the larva 

 is parasitic in certain earthworms and Doctor Townsend is of the 

 opinion that there may be two generations in the latitude of Wash- 

 ington, though available data indicate but one in New York State. 

 Clusters of the flies can be destroyed by dusting them liberally 

 with fresh pyrethrum or insect powder, or the insecticide may be 

 molded into moist cones and burned. In any event the stupefied 

 insects should be swept up and destroyed. It has been found ex- 

 tremely difficult to fit windows and screens tightly enough to ex- 

 clude these flies, and with this in mind we would suggest that 

 trouble may be avoided to some extent at least by keeping the rooms 

 open and thoroughly ventilated, since this fly displays a marked 

 preference for dark and undisturbed retreats. 



Biting House Fly 



Stomoxys calcitrans Linn. 



This insect resembles the house fly very closely indeed and is 

 most easily distinguished by the moderately sharp pointed mouth 

 parts which differ greatly from the stout, lobed proboscis of the 

 house fly. It is this insect which has given rise to the general belief 

 that house flies may bite before a rain. It is more an outdoor stable 

 fly than a house fly. This insect has been under suspicion as a 

 carrier of infantile paralysis, but this has by no means been proved, 

 though it or a closely allied species is credited with being an agent 

 in the dissemination of surra. 44 



There is also a record of Stomoxys being a mechanical carrier of 

 a plaguelike disease in rodents, which can be transmitted to man. 45 



The maggots of this insect develop freely in decaying oat rather 

 than wheat straw, or in strawy manure. The eggs are laid in 

 masses several inches below the surface. The female may deposit 

 at least 632 and possibly 820 eggs. As many as twenty lots may be 

 deposited by one fly. 46 They hatch in from I to 4 days, the larval 



44 Hoole. Ceylon Admin. Rep'ts Vet. 1911-12. 



45 Wayson. Pub. Health Rep'ts, Washington, 29 :339O-93. 1914. 



46 Mitzmain. Phil. Jour. Sci., 8 129-48. 1913. 



