26 



PARASITES OF THE DOIMESTIC ANIMALS 



jnipal case at the tlioi'ax, there is an apparejit adapta.l)iUty in this re- 

 versal of position. 



The common house or "lain banel" mosquito of the Northern 

 United States, Cule.i- piotgens (Fig. 12), breeds throughout the summer, 

 Ijroods develo])ing wli(>rever there may be standing water, as in pools, 

 troughs, cans, discarded bottk-s, gutters, etc. The adults of this species 

 may pass the \\inter in the shelter of darkened retreats, such as the 

 cellars of houses, behind furnitui'e, outbuildings, and wood piles, 

 emerging from their hibernation in the spiing to deposit their eggs. 

 Many first spring broods in temperate climates hatch from eggs that 

 have been carried o\'er the winter months, the eggs seeming to stand 

 desiccation in dry locations to ]H-omptly hatch in pools left by the spring 



Fig. 11. — Pupa <>{ Culcx pungens at left; puija of Anopheles quad- 

 riniaculatus at rif^ht — greatl.v enlarged {after- Howard, B\il. No. 2.5, 

 Bureau of Entomology, Dept. of Agr.). 



rains, or even in water from melting snow during the warmer days of 

 late winter. 



In refutation of the assertion often made that mosciuitoes cannot 

 ovulate without a meal of warm blood, it has been demonstrated in 

 experiments upon some of our common blood-sucking species that fe- 

 males as well as males can not only l^e kept alive for a long period when 

 given access only to plants, but will, under such conditions, repeatedly 

 breed. 



Pathologic Importance. — While their preference for blood has made 

 them of primary general interest as pests in the habitations of man, 

 mosquitoes are of the greatest importance medically, not only as possil)le 

 direct transmitters of disease, but as specific bearers of infection, bring- 

 ing about such diseases as malaria, yellow fever, and possibly filariasis. 

 There have been many convincing demonstrations that malaria is 

 transmitted exclusivelj' b}^ the bite of mosquitoes, only, however, by 

 .species belonging with the anopheles group, of which Anopheles quadri- 



