PARASITOLOGY. 25 



the flies away. Coal-tar solutions, such as creolin 

 and kreso, keep the flies away for only a short 

 time. 



Stomoxys Calcitrans (Stoma — mouth, calcitro — sting). 



Syjionyms. — Stomoxys stabulans; stable-fly; sting- 

 ing fly. 



History. — Widely distributed, they appear in the 

 latter part of summer. They were first described in 

 1761. 



Descriptioji. — It is about the size of the house-fly. 

 When at rest the wings are nearly at right angles. 

 The head is provided with a solid, elongated stylet- 

 shaped proboscis, bent near its base. 



Life Cycle.— The ova are laid in the fresh feces, 

 where the larval stage is passed. The pupal stage 

 is passed in the ground. 



A?ii?nals Attacked. — It enters stables and attacks 

 horses and cattle. Its bite is severe, causing vesi- 

 cles, which rupture and produce scab ; the hair be- 

 comes erect and the legs become sore. This fly has 

 been thought to carry the germs of anthrax and of 

 glanders, by attacking healthy animals soon after 

 diseased ones have been feasted upon. 



Chrysops Vittatus. 



Synonyms. — Deer fly; striped ear fly. 



Description. — About one-half the size of the common 

 house fly. Narrow slender thorax and abdomen, yellowish 

 with brownish-black stripes running longitudinally of the 

 thorax and abdomen. The wings are set out from the 

 body similar to the stomoxys and are banded with brown 

 and white stripes. The mouth parts are provided with a 

 stjdette with which it pierces the skin and sucks blood. 



Distribution. — They are common in the Rocky Mountains, 

 wlhere they are a great annoyance to horses and cattle. 



