360 



FAMILY MUSCID^. 



(House Flies, Blow Flies.) 



We will give an outline of the life history of the 

 house fly, which will serve as a type for the group 

 (Plate 40, Figs. 1, 6). 



The common house fly, Mitsca domcstica, lays her 

 eggs in decaying vegetable matter, and in manure, 

 more especially horse-manure. It is this fact whicli 

 renders them so numerous along country roads and 

 in paddocks. Making proper manure heaps and 

 covering it with soil or sprinkling with lime is often 

 resorted to in order to prevent the breeding 

 of flies in garden manure heaps. Eacli female 

 lays about 100 eggs, and they hatch out in six or 

 seven hours. The maggots feed on the decaying 

 vegetable matter, and are ready to pupate in five 

 or six days. They are adult in five days after 

 pupating. The total length of time from the ^^^ 

 to the emergence of the adult is about two weeks. 

 In summer there are about one dozen generations 

 in the one season. 



The maggot or larva is soft and of a creamy 

 colour; it is narrow at the head and thick and 

 blunt at the end. (Plate 40, Fig. 2.) The head is 

 small, characterised by a pair of dark jaws. Near 

 the mouth are a series of minute pores; these are 

 openings of the tracheal tubes. At the posterior 

 or thick end of the maggot there is a plate, on 



