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Life History of the Blow Fly. 

 (Plate 44.) 



The eggs are laid on animal or vegetable matter. 

 Blow flies are pests in the house, laying eggs on food. 

 We know how we have to guard meat in 

 the summer-time, especially on the Mountains 

 or in the country; indeed, in the city, too, it is 

 often difficult to keep meat from the ravages of 

 these flies. The eggs are laid on meat, etc. ; 

 or, in very hot weather, tiny maggots may be de- 

 posited. We have observed a blow fly deposit young 

 maggots, about an eighth of an inch in length, on 

 meat. 



The maggot or larva (Plate 44, Fig. 1) is smooth 

 and of a creamy colour. It can ''hop" by 

 curving the body and then straightening it 

 quickly. Maggots move about freely in semi-fluid 

 decaying matter. The head is very small, and 

 cannot be clearly defined from the thorax, the most 

 noticeable feature being a strong, dark pair of 

 chitinous jaws. The head can be withdrawn and 

 hidden by the thoracic segments. 



The maggots moult and at last pupate in the 

 ground, or they may pupate in the medium (if solid) 

 in which they are feeding, the last larval skin being 

 changed into the seed-like puparium. When the adult 

 fly escapes one can see the little round lid it pushed 

 off from the end of the puparium. 



The mouth, like that of the house fly, is fltted for 

 sucking only. The end of the proboscis is pro- 

 duced into a broad, lip-like organ with a series of 

 grooves, through which the moisture runs when 



