Carpenter et al.: Mosquitoes of Southern U. S. 7 



to as wild or sylvan species; while those which readily enter buildings to feed 

 are usually referred to as domestic or house-frequenting species. Most species 

 of Anopheles and Culex found in the southern United States prefer to rest 

 by day in such places as buildings, culverts, hollow trees and caves. Their 

 relative abundance can usually be determined by making periodical collec- 

 tions in these shelters. Several techniques for collecting adult mosquitoes are 

 discussed here. 



Natural Shelters. — In making collections of mosquitoes in diurnal resting 

 places for the purpose of determining densities, numerous favorable shelters 

 should be e.xamined. After an extensive preliminary survey has been made, 

 stations should be selected from which regular weekly collections are to be 

 made throughout the active mosquito breeding season. 



When collecting mosquitoes inside houses, one should search carefully, 

 particularly in dark, protected places. Large numbers of mosquitoes are some- 

 times found on window screens after sundown, where they may be attempt- 

 ing to leave the building in which they found refuge during the day. On 

 the other hand, they may be collected during the night or early morning on 

 the outer surface of window and door screens where they may be trying 

 to enter. Window traps are used in some areas to sample species attempting 

 to enter a building. Mosquitoes are frequently found concentrated in large 

 numbers in stables where domestic animals are housed. 



The coloration of some species enable them to blend with their surround- 

 mgs, making it very difficult for them to be seen. A flashlight properly 

 focused is usually necessary for spotting specimens resting in dark places. 

 After one has collected all visible specimens, it is frequently advisable to prod 

 in corners, trash heaps, and dark places, collecting the disturbed mosquitoes 

 in flight with a midge net. 



Artificial Shelters. — In army camps where practically all the buildings are 

 well-screened, it is often difficult to find well-located stations in which to 

 make collections. Nail kegs and small boxes are claimed by some workers to 

 be satisfactory for this purpose when placed near extensive breeding areas 

 (68, 175). A small privy-type house, however, has been proven by malaria- 

 control workers in the southern United States to be more satisfactory (Fig. 1). 

 The privy-type house may be constructed of weather-beaten lumber and 

 should be approximately 4 feet square and 7 feet high. The front is left 

 open to a height of about 30 inches from the ground. 



Mosquito Traps. — Several types of traps have been devised for use in 

 connection with mosquito surveys and mosquito control. It cannot be said 

 that any of the traps now in use are of much value as an anti-mosquito 

 measure, but some of them do provide valuable information as to the species 

 present in a given locality and their abundance. The more common types 

 of traps used for samplmq and evaluatino mosquito densities are the New- 

 Jersey Mosquito Trap (Fig. 2) and stable traps. 



The New Jersey trap should be fastened to a post by means of bolts, or 



