A mark-release-recapture study on the spatial distribution of host-seekinganophelines in northern Thailand

A mark-release-recapture experiment was conducted at Mae Taeng, Chiangmai, Thailand, in November 1990 to examine the movement of released host-seeking mosquitoes in a heterogeneous environment. A total of 1,848 mosquitoes of nine anopheline species was field-collected, marked with fluorescent dye, a nd released. Adult collections were made for four nights after the release at five collection sites surrounding the release site. Three different attr actants, dry ice (5 kg/site/night), human, and cow bait were used to collec t a large number and a wide variety of adult mosquitoes. The recapture rate of released mosquitoes differed among species, ranging from 0 to 7.5%. The species composition was significantly different among collection sites and collection methods, and samples from dry ice collection showed intermediat e species composition between those from human and cow bait collections. Th e spatial distribution of released mosquitoes was not significantly differe nt from that of unmarked mosquitoes. Different behavioral responses to hete rogeneous environments by different species of host-seeking mosquitoes was suggested as the underlying mechanism of species-specific spatial distribut ion of mosquitoes in the study area.