Norton] MOSQUITO EXTERMINATION IN NEW YORK 385 



manner as are the New York marshes. The New Jersey Mosquito 

 Extermination Commission is testing a Texas plan — the use of 

 bats to rid the cities and towns of the pest. 



In San Antonio, Texas, a municipal bat roost is maintained 

 which shelters about 250,000 bats; it cost about $1,500 to erect 

 and maintain. Each bat, it is claimed, has a nightly capacity of 

 250 mosquitoes. But this method, it would seem, remedies the 

 effect and not the cause. 



The mosquitoes, Family Culicidae, do not form a large insect 

 group, but are an important one. They are a pest, and carry 

 disease. They range from the tropics to Alaska, Lapland and 

 Greenland. They are true air-breathers but are born in stagnant 

 water. They breed rapidly and pass through several generations 

 a year; the adults hibernating in out-houses, cellars and cold 

 garrets. The main purpose of the adult seems to be propagation 

 of the species; its life seems to be dependent only upon this 

 opportunity. Females are normally plant-feeders, their mouth- 

 parts very different from the flesh-sucking males. 



Five genera are represented in this country: Anopheles, 

 Aedes, Megarhinus, Psorophora and Culex. Most of our species 

 belong to the genus Culex. Those of the genus Anopheles carry 

 malaria. Those of the genus Aedes are very small; those of 

 Megarhinus and Psorophora are large — known as gallinippers. 



Mosquitoes seldom fly far. Anopheles, of which, in the United 

 States, we have three species, appear to be of extremely short 

 flight, while Culex seldom leave their breeding places. Three 

 methods of extermination are used: drainage, use of kerosene 

 on surface of breeding waters, and the introduction of fish into 

 Ashless ponds. 



Eggs, numbering from 200 to 400, are laid in a raft-like mass, 

 gray-brown from above and silvery white from below. Laid in 

 the early morning the eggs will hatch, on a warm day, by two in 

 the afternoon. The wigglers are very active, breathing at the 

 surface, descending for food. The wiggler molts three times 

 reaches maturity and transforms to a pupa in a minimum of 

 seven days, in hot weather ; in cool weather this takes much longer. 

 The pupa stage lasts two days, longer in cooler weather, when the 

 skin splits and the adult mosquito emerges. 



