HOVER FLIES. :{51 



The pupa drops to the ground after remaining for 

 some time on the plant. This is the life history of 

 the common hover flies such as Syrphiis viridiceps 

 and Syrphus pucillus, whose larvae are found on gar- 

 den plants, wheat, etc. 



But some species of syrphid flies have larva) with 

 elongate tubular processes at the end of the body, 

 which can be extended to two or three inches, and 

 contracted again. By this means they get a supply 

 of air, which enables them to live in muddy water 

 and in fluids caused by decomposition of animal or 

 vegetable matter. There is a curious introduced 

 syrphid fly called the *' drone fly" or "bee fly." 

 It is more like a bee in general appearance, and its 

 larva has the ''rat-tailed" body described above 

 (Plate 43, Fig. 4 a). Its name is Eristalis tcna.v. 



