656 DOMESTIC ANIMALS, DAIRYING, ETC. 



than the larval. In two or three days the pupa transforms to the 

 adult mosquito and becomes the notorious household pest, the 

 entire life-cycle being a matter of eleven to eighteen days. 



The only remedy for adult mosquitoes is protection by screen- 

 ing, or the burning of insect powder. These remedies bring only 

 temporary relief and do not remove the source of the nuisance. 

 The importance, then, of not allowing mosquitoes to develop be- 

 yond the pupal or final aquatic stage is evident. No practical 

 method of destroying adult mosquitoes is known. 



The length of the life of adult mosquitoes varies. It is diffi- 

 cult to get insects to repeat correctly in confinement what their life- 

 history and habits would be under natural conditions; therefore 

 the length of the life of the adult cannot be determined by experi- 

 ment. As a rule the males of insects do not live any great length 

 of time after maturity, and the females die soon after depositing 

 their eggs. In a tropical country, like Hawaii, where no difficulty 

 is encountered by the gravid female in securing favorable breeding 

 places throughout the year, the length of the adult life is probably 

 at the most only a matter of several weeks. In cold countries the 

 male mosquitoes are known to die in the early winter and the 

 females hibernate during the cold season, a period of several 

 months, until suitable conditions for egg-laying prevail. 



Migrations of Mosquitoes. The adult mosquito is a very 

 feeble flyer and is usually found in the vicinity of its breeding 

 place. Instances are on record where mosquitoes have been car- 

 ried in large numbers for long distances by the wind, but invasions 

 from one locality to another are exceptional. It is well known that 

 on windy days mosquitoes are less in evidence. It is evident from 

 the structure of their organs of flight that mosquitoes cannot long 

 endure in a high wind. In an infested locality, mosquitoes are al- 

 ways in evidence immediately after a wind subsides, especially in 

 places where the vegetation is abundant, in the foliage of which 

 they seek shelter from the wind. Smith says that the habits of 

 mosquitoes in regard to their flying any distance varies with the 

 different species. He discusses a salt-water species, Culex sollicitans, 

 which is apparently a true migratory form. It can be stated with- 

 out qualifications that the source of mosquitoes is generally the im- 

 mediate vicinity of the infested places. Invariably the source of 

 mosquitoes infesting any district has been found to be near by nat- 

 ural and artificial collections of water, usually artificial collections 

 in the immediate vicinity. (Sp. Bui. T, N. J. E. S.) 



The Food of Adult Mosquitoes. Their food consists of the 

 blood of animals and the juices of plants and fruits. Mosquitoes 

 are normally plant-feeding insects and only the female is a blood- 

 feeding insect when that is obtainable. The male satisfies his appe- 

 tite on the juices of fruits or other liquids since the proboscis is not 

 constructed, as is that of the female, for piercing anything with 

 any degree of resistance, as the skin of animals or the epidermis 

 of plants. Howard says, speaking of female mosquitoes: It is safe 



