SOME WINTER OBSERVATIONS OF MUSCID FLIES.* 



AIax Kisluk, Jk. 



If the hibernation of the house-fly (Musca domestica L.) 

 and the other disease disseminators of the same family 

 (Muscidae) could be prevented, the early spring and summer 

 generations would be controlled. Although these flies are the 

 most common domestic pests the economic importance of a 

 thorough study of their hibernation stages was but recently 

 recognized. It seems that in the past too much had been 

 assumed without actually experimenting to prove the assump- 

 tion. With the knowledge of several diverging theories in 

 mind, the author began a study of the hibernating stages 

 of 'Musca domestica L. at College Park, Maryland, 1914-15, 

 under the direction of Prof. E. N. Cory, Maryland State 

 College, and continued, 1916-17, at Columbus, Ohio, under 

 the direction of Prof. Jas. S. Hine, Ohio State University. 

 (Dr. Gary deN. Hough's keys w^ere utilized in determining the 

 species herein discussed). 



In order to find out experimentally, how long adults of the 

 house fly would live confined in cages under otherwise natural 

 winter conditions, tests extending throughout the winter were 

 conducted in a large screen insectary and in an unheated stable 

 at College Park, Maryland. The flies which were used in the 

 above experiments were confined in rectangular wire cages 

 (breeding cages — 12 x 12 x 24 inches), which had a hole 6 inches 

 in diameter in the upper half of one of the long sides. This 

 opening was protected by a black-cloth sleeve and was used as a 

 convenient method for admitting or replacing adults, food 

 and manure. The adults were fed with fresh milk, which was 

 daily supplied them in small dishes, packed with absorbent 

 cotton. Fresh manure was also placed daily in a small flat 

 dish in each cage as a medium in which eggs might be deposited. 

 When one lot of adults died they were removed and a new lot 

 installed. The new lots of flies were bred out in the greenhouse 

 as will be described elsewhere in this paper. 



These experiments show the greatest longevity of the adult 

 to be 44 days (December 12, 1914-January 29, 1915), extreme 

 temperatures 15° -63°, mean 45°, in the unheated stable 



♦Extract from a thesis written as part requiremental for a master's degree 

 at Ohio State University. 



28.S 



