Submitted to: American Journal of Tropical Medicine and Hygiene
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/5/1996
Publication Date: N/A
Interpretive Summary: Until the end of the Second World War, malaria was still a serious problem in the southeastern United States. The mosquito that was responsible for transmitting this deadly disease was Anopheles quadrimaculatus. Recently, this laboratory has found that "A. quadrimaculatus" is actually five different species of closely related mosquitoes. This study helps to answer the question "Which of the members of A. quadrimaculatus complex of mosquitoes are most important from the human perspective?" by determining that one species of the complex feeds on humans at a much high rate than two other A. quadrimaculatus species present in the same area at the same time. Mosquitoes that frequently feed on humans are more likely to be biting pests and transmit malaria than species that seldom feed on humans. This has important practical implications for mosquito control operations: probably only one of the three species of A. quadrimaculatus studied is a serious human pest, so there is no reason to devote expensive resources to controlling the other two species.
Technical Abstract: We compared rates of feeding on human hosts for blood engorged female Anopheles quadrimaculatus species A, B and C1 collected from daytime resting sites in Manatee Springs State Park, Levy County, Florida, during 1992-1993. Quick-blot DNA probes were used to identify mosquito taxa and also the presence of human blood in the mosquito gut. In collections from a camping area, human blood feeding rates differed significantly among mosquito species (10.7% (19/177), 0% (0/59) and 1.2% (4/345), respectively, for species A, B and C1). In collections from a woodland site (1 km from the campground), 1.5% (2/129) species B mosquitoes had fed on humans, whereas none of 19 species A or 159 species C1 females had done so. The higher rate of blood feeding on humans by species A females indicates a preference for human hosts or a higher overall probability of mosquito-human contact for species A compared with B or C1. Species A thus appears to be more likely to be a biting pest of humans and potential vector of introduced malaria than either species B or C1.