The Mosquitoes of New Jersey 167 



made their way for a distance of ^ mile to a village, apparently in 

 search of food, and that they or others of the same species made a 

 return flight before morning. 



The fresh-water swamp mosquito when bred in small numbers 

 seems to have the same movement as the house mosquito, but when 

 produced in enormous numbers, over a large area, may cover long 

 distances in its search for food. Under such circumstances it is like- 

 ly to find breeding places near its food supply and probably returns 

 rarely to the place where it was bred. 



A small brood of salt-marsh mosquitoes (A. cantator and A. 

 sollicitans) will travel only a short distance for food and return to 

 the marsh for laying eggs, but a very large one will throw off an 

 immense number of migrants which will fly for long distances over 

 territory in which no suitable breeding ground exists. Of course, 

 such flights multiply the insects' chance for obtaining food and also 

 in some cases lead to new breeding grounds. The fact that most 

 of the migrants exhibit undeveloped ovaries does not necessarily 

 mean that breeding cannot take place when the new breeding grounds 

 are reached. 



It seems as if intense breeding over large areas is followed by 

 wide distribution of the adults of the house mosquito (Culex 

 pipiens), the fresh-water swamp mosquito (Aedes sylvestris) and 

 the salt-marsh mosquitoes {Aedes cantator and Aedes sollicitans) . 

 It is possible that under similar conditions Anopheles (some of 

 which carry malaria) would be found to act similarly. 



External Factors Which Influence Flight 



Without doubt, low temperature reduces, may suspend, or even 

 destroy, the activity of the adult mosquito. Excessively high tem- 

 perature always retards mosquito activity. A warm temperature, 

 80° F., is extremely favorable. 



Light is avoided by most species and some have such an abhorence 

 of it that they will not become active while it is strong. 



Atmospheric moisture has a very powerful effect upon the adult. 

 High percentages are favorable and low percentages deadly. Rain 

 itself is decidedly injurious and prevents adult mosquito activity. 



Air movements greatly influence mosquito activity. A stiff breeze 

 is usually quite sufficient to stop their movements and to compel them 

 to cling to shelter. Winds of low velocity (10 miles an hour or 

 less), of high temperature (about 80° F.) and high humidity appear 

 to be the ones that favor long flights. 



