Manchester Memoirs, Vol. li. (1906),- No. \. 



I. A Preliminary Account of the Life-history of the 

 Common House Fly {Musca domestica L.). 



By C. Gordon Hewitt, B.Sc, 



Demonstrator of Zoology in the University of Manchester. 

 Received and Read October 2nd, 1906. 



During the summer of this year I have been making 

 some investigations on the life-history of the Common 

 House Fly, Musca domestica L. for a monograph which I 

 am preparing on that insect. As the life-history of M. 

 domestica has not been studied previously in this country, 

 so far as I am aware, a short preliminary account of the 

 results obtained from this year's experiments may be of 

 some interest. 



The life-history has previously been studied in America 

 by Packard ('74) at Salem, Mass., and more recently by 

 Howard (:02) at Washington. Their results differ slightly 

 and are given at the end of the accompanying table. The 

 female fly lays about one hundred and twenty eggs in the 

 crevices of horse excrement, which must be fresh or the 

 flies refuse to deposit their eggs. I experienced consider- 

 able difficulty in getting the flies to lay their eggs in 

 confinement. When excrement is exposed before an 

 open window large numbers of the eggs of other species 

 of flies, which inhabit houses, are deposited, chiefly, I 

 found, those oi Ant homy ia radicum L. 



The experiments were begun early in August and 

 continued to the end of September. During this time 

 five lots of larvae were reared, each batch experiencing 

 different conditions of temperature. By keeping the 

 conditions as regards moisture and supply of food uni- 

 form, I was able to study the effects of the variability of 



October 23rd, 1906. 



