Seasonal occurrence and abundance of Aedes triseriatus and other mosquitoes in a La Crosse virus-endemic area in western North Carolina.

The species composition and population abundance of mosquitoes were investigated from May to November in 1989 and 1990 on the Cherokee Indian Reservation, an area of western North Carolina endemic for transmission of La Crosse (LAC) virus. Mosquitoes representing 6 genera and 13 species were collected. Aedes triseriatus was the most abundant species collected, comprising over 98% of mosquitoes collected by ovitrapping and CO2-baited suction trapping, and 88% of resting adults collected by vacuuming vegetation and leaf litter. Culex restuans and Anopheles punctipennis were common but much less frequently collected. Host-seeking and resting Ae. triseriatus were most abundant in early to midsummer, whereas gravid Ae. triseriatus was most active in the fall. The previous occurrence of cases of LAC encephalitis was concordant with the seasonal activity of gravid but not host-seeking or resting Ae. triseriatus.