A mark-release-recapture study on the spatial distribution of host-seeking anophelines 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, and released. Adult collections were made for four nights after the release at five collection sites surrounding the release site. Three different attractants, dry ice (5 kg/site/night), human, and cow bait were used to collect 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 intermediate species composition between those from human and cow bait collections. The spatial distribution of released mosquitoes was not significantly different from that of unmarked mosquitoes. Different behavioral responses to heterogeneous environments by different species of host-seeking mosquitoes was suggested as the underlying mechanism of species-specific spatial distribution of mosquitoes in the study area.