OUK FEIENDS AND FOES 



155 



by a jerky motion, ascending' at times to the surface 

 for a supply of air. This they take in through a slen- 

 der tube at the caudal end of the body. The pupa,' 

 are active, and can readily be distinguished from the 

 larva?. The head of the larva or wiggler is not natu- 

 rally large. The pupal head has the feet and developing 



Fio. 123. Full-grown mosquito larva on left. Pupa on right. Much enlarged. 

 (After Howard.) 



wings folded around it, so that the pupa is quite easily 

 distinguished from the larva by the size of its head. 

 This distinction can be made as the insects are observed 

 in the water in the basin in which they have been col- 



