February, '13] BISHOPP: stable fly -* 117 



cattle in regard to securing protection by entering mud or assembling 

 close to sheds or stables. 



Life History and Habits 



Breeding Places. A somewhat careful examination has shown 

 that the stable fly breeds in the following substances : The list is given 

 in the approximate order of importance. The straw of oats, rice, bar- 

 ley, wheat, horse manure, lot manure and cow manure. It has been 

 determined that pure horse and cow manure are much less attractive 

 to the fly than when a considerable quantity of straw is intermixed. 

 By lot manure is meant the scattered, finely pulverized manure which 

 occurs in barn lots. Examinations of accumulations of weeds have 

 failed to show the presence of Stomoxys larvae. This is also true of 

 alfalfa hay which was in a rotting condition. The fly has been bred 

 in broken-up upland hay such as is found around the base of stacks 

 or in barns where feeding is done. The vast majority of flies, how- 

 ever, undoubtedly breed in decaying straw, either pure or mixed with 

 manure. 



An examination of oat and wheat straw stacks during the latter 

 part of August and early September, 1912, showed that far more 

 larvse were developing in oat straw than in wheat straw. The former 

 appeared to be more suitable because of its compact texture after being 

 wet and the greater amount of leaves. Most of the flies were breeding 

 in the lower portions of the stacks although a few pupae were found 

 on the very top of a stack fifteen feet high. After the larvae develop 

 they show a tendency to work downward, or at least to follow the 

 moisture as the surface of the stack dries. Pupation occurs anywhere 

 in the straw but pupae are usually more numerous between layers of 

 straw or between the straw and the surface of the ground. At Addis, 

 La., the writer found large numbers of Stomoxys breeding in stacks 

 of rice straw, the conditions under which they were found being quite 

 similar to those in oat straw stacks. 



Larvae have often been observed when small to penetrate between 

 the epithelium layers of the stalk or leaves of grain when moistened 

 in the straw stacks. As the larvae become larger they often enter the 

 straws and feed within and pupation frequently occurs in this position. 



Habits of the Adult. The adults, both male and female, are 

 ready to partake of a meal of blood as soon as the body and mouth 

 parts are thoroughly hardened after emergence. The host appears 

 to be located largely by sight and on cattle the fly has been frequently 

 seen to alight on the back and as soon as disturbed by the switching 

 of the tail it flies directly to the outside of the forelegs just below the 



