50 



Fig. 46. Sheep bot Fly. 



Fig. 4j. Ox bot Fly Larva. 

 The Red-tailed 



Westwood. This little fly, not bigger 



than the common house fly, is the 



great obstacle to the exploration of 



Central Africa. "It is not danger- 

 ous to man, to any wild animals, 



nor to the pig, the mule, the ass or 



the goat. But it stings mortally 



the ox, the horse, the sheep, and 



the dog, and renders the countries 



of Central Africa uninhabitable for 



these valuable animals." 



The genus Tachina, of which Fig. 



47 represents a species, is parasitic 



in caterpillars. 



Tachina doryjjhorce, Eiley, feeds on the larvte of the potato- 

 beetle. 

 Tachina Fly, Nemoraea leucanice, Kirkp., Fig. 48, is parasitic on 

 the army worm moth, Leucania unipuncta, Haworth. The fly deposits her eggs upon 



the fore part of the body of the worm. Prof. 

 Comstock says " That as many as eighteen eggs 

 are laid on a single worm, but the visual num- 

 ber is about five. These eggs are so ingeniously 

 placed that the worm can by no possibility reach 

 them with its jaws, or get rid of them in any 

 other way. Mr. Howard says that he has 

 searched for hours in a field infested with 

 army worms without finding a single full- 

 grown worm that did not carry one or more of these eggs 

 upon its back." In Fig. 32, just underneath the fly is 

 shewn the forepart of an army worm exhibiting the placing of the parasitic eggs. 

 Sarcophaga, the Flesh Fly, is one of the viviparous species alluded to before. 



Fig. 49 is an enlarged repre- 

 sentation of Sat'cophaga carnaria, 

 Linn. The flesh fly and Fig. 50 

 shows the maggot. 



The female is exceedingly pro- 

 lific. The entomologist, DeGeer, 

 vouching for the development of 

 20,000 larvae in one female. 



These flies sometimes deposit 

 their larvje on living animals, and 

 thus become parasites. 



Prof. Comstock says that 

 " specimens of a flesh fly were 

 reared from pupa of the Cotton 

 worm, Aletia Arc/iUacea, ^^^^^^^- j^^^y^of 'Flesh Hy. 

 , These proved to be specimens of 

 ' Sarcophaga Sarracenice, Riley, a probable Ameri- 

 can variety of that wide - spread scavenger, S. 

 Carnaria, a species common to Europe, America^ 

 and Australia, certainly and probably else- 

 where to be found. Sarracenice was first de- 

 Fig. 49. Flesh Fly. scribed by Prof. Riley as feeding upon the dead 

 insects to be found in the leaves of Sarracenia, the pitcher plant. Fig. 51 represents 

 the insect in all its stages. 



The AnthomyicG are to be found about flowers, and their larvae live on decaying 



