RELATIVE ABUNDANCE AND SPECIES COMPOSITION OF MOSQUITO POPULATIONS (DIPTERA, CULICIDAE) IN A LACROSSE VIRUS-ENDEMIC AREA IN WESTERN NORTH-CAROLINA

Container surveys were conducted in 5 communities on the Cherokee Indi an Reservation, an area of western North Carolina endemic for transmis sion of La Crosse (LAG) virus, to determine the potential for peridome stic mosquito breeding, the relative abundance of mosquito species, an d the standing crop of mosquitoes per residence. Eleven species of mos quitoes were collected, but 80.9% of all mosquitoes reared from contai ners were Aedes triseriatus (Say). All communities averaged >6 contain ers per residence, indicating that the potential for mosquito producti on was high. The Breteau index and mean standing crop of adults per re sidence in the 5 communities were highly concordant. LAC virus was iso lated from 2 pools of 56 female and 36 male Ae. triseriatus adults tha t were reared from eggs collected by ovitraps. The minimum field infec tion rate was 0.26 per 1,000 adults tested. Aedes triseriatus, the mos t frequently collected blood-fed mosquito (98/112 blood-engorged speci mens), fed predominantly on dogs (40.4%), rabbits (26.6%), and turtles (22.3%). Only 7.5% of the bloodfed mosquitoes had fed on eastern chip munks. Peridomestic conditions on the Reservation appear to contribute to the maintenance of LAC virus transmission. Production of Ae. trise riatus occurs in artificial containers discarded around residences, an d wooded areas immediately adjacent to residences provide resting cove r for mosquitoes as well as suitable habitat for LAC virus reservoir h osts.