172 INSECT AND VERTEBRATE ENEMIES 



the larva of M. domestica was never observed to devour it alone, 

 a number of other individuals usually joined in the feast. Nor 

 were the larvae of M. stabukins ever seen to devour each other. 

 Portchinsky also found that they would bore into and eat the 

 bodies of dead flies. The habits of M. stabidans are considered 

 later (pp. 207-210). 



Vertebrate Enemies. 



That the house-fly has a number of vertebrate enemies, exclu- 

 sive of man, is a matter of common observation. Cats will some- 

 times sit in a window and catch flies. Rats have also been observed 

 destroying flies. Birds will destroy M. domestica in both the 

 adult and larval stages though not in preference to other species 

 of insects. 



Poultry will feed upon the larvae and pupae of M. domestica 

 which they may find in the stable-yard and are sometimes of some 

 service in this respect. 



Lizards, toads and frogs will capture the adult flies whenever 

 an opportunity occurs, but their influence in the matter of control 

 is too slight to be noticeable. 



