I 



Mosquitoes in General 



The Life Eouiid of Mosquitoes. 



ALL mosquitoes, so far as known, are aquatic in 

 their early stages. It has never been shown that 

 any of them lay their eg-g-s anywhere except in 

 water. Their larvae live under the surface of the water, 

 although they are true air-breathers ; that is to say, they 

 must come to the surface of the water to breathe. This 

 breathing is performed through branched tracheal tubes 

 within the body, which terminate in an orifice at the end 

 of a prolongation of one of the last segments of the ab- 

 domen, and which from this fact is known as the respira- 

 tory tube. This tul^e is pushed at intervals up through 

 the surface film of the Avater and air is drawn down into 

 the tracheae. The larvae feed either at the surface or 

 below the surface, and their food is composed of all sorts 

 of floating particles, and in the case of some of the larger 

 forms they may even bite aquatic vegetation. They are 

 rajud breeders and pass the pupal condition also in the 

 water, but floating normally at the surface. In the pupae 

 they breathe not from a breathing tube at the anal end of 

 the abdomen, but from two trumpet-shaped tubes issuing 



1 



