THE ANATOMICAL LIFE OF THE MOSQUITO 



By R. E. SNODGRASS 



Research Associate 

 Smithsonian Institution 



INTRODUCTION 



Mosquitoes are not popular with warm-blooded animals, but from 

 their own standpoint they have been highly successful insects, until 

 recently when they have been attacked with poison sprays and have 

 had their larval habitats drained. Success, however, is always to be 

 admired whether in man or an insect, and it is instructive to see how 

 it has been achieved. The mosquitoes have attained their place in the 

 world by the evolution of highly specialized anatomical characters. A 

 study of their anatomy may help some in our war against them, and 

 it will give a most interesting example of how insects have evolved 

 structures fitting them for particular ways of living and of feeding 

 that have made them so successful in the struggle for existence. 



The family name of the mosquitoes is Culicidae, and they belong 

 to the order Diptera, or two-winged flies, which in turn are members 

 of that large group of insects in which the young, or larvae, are very 

 different from their parents in form, structure, and habits, and must 

 undergo a renewed growth to attain the adult state. We are so ac- 

 customed to seeing young animals grow up gradually into adults that 

 it seems very remarkable that an animal can completely change its 

 shape and structure in the middle of its life. The young mosquito, for 

 example, hatches from the egg as an active larva having no resem- 

 blance to its parents but fully adapted in its structure for living and 

 feeding in the water. During its life the larva sheds its cuticle four 

 times. At each of the first three ecdyses it comes out a little larger 

 than before, but with little change otherwise. On shedding the fourth 

 cuticle, however, a very different creature, the pupa, emerges. The 

 pupa has all the adult organs, though in an incomplete state of de- 

 velopment, and is clearly a preliminary adult. With a final moult and 

 ecdysis the completed mosquito appears, equipped for an entirely dif- 

 ferent life from that of the larva. 



It is commonly said that the larva is metamorphosed into the adult 



SMITHSONIAN MISCELLANEOUS COLLECTIONS, VOL. 139, NO. 8 



