Mosquito collections following local transmission of Plasmodium falciparummalaria in Westmoreland County, Virginia

A 63-year-old woman from Colonial Beach, Westmoreland County, VA, was diagn osed with Plasmodium falciparum malaria on July 19, 1998. The woman had no history of international travel, intravenous drug use, blood transfusion, o r other risk factor for contracting the disease. She seldom left the county and generally spent her evenings indoors, leading to the conclusion that s he had been bitten locally by an infected mosquito. Colonial Beach is host to a population of migrant agricultural laborers from areas in which malari a occurs, but a blood survey of 89 Haitians and Mexicans failed to find Pla smodium parasites, specific antibodies, or clinical cases of malaria. Mosqu ito surveys were conducted during 2 days (July 22 and 28, 1998) with carbon -dioxide-baited light traps, larval and pupal collections, and landing coll ections. Thirteen species of mosquitoes were identified morphologically, in cluding 4 potential vectors: Anopheles crucians, An. punctipennis, An. smar agdinus (new state record), and An. quadrimaculatus s.s. (new state record) . Identifications of the latter 2 species were confirmed by sequencing of t he ITS2 DNA region from adults reared from locally collected larvae. Anophe les smaragdinus was the most common biting species among the potential vect ors, although An. crucians was the most abundant in other kinds of collecti ons. In addition, Ae. albopictus was collected in Westmoreland County for t he 1st time.