Anopheles darlingiRoot (Diptera: Culicidae) in the Suriname rain forest

Abstract

Females ofAnopheles darlingiRoot were the commonest (98·6%) of 5464 anophelines taken in 866 man-hours of human bait catches at night, in or near houses in the rain forest in Suriname during 1979–81, but their abundance could not be related to the prevalence of human malaria. In most endemic areas, few females were taken. At Aseli Kamp (4°17'N, 53°24'W) on the Lawa River, biting females were most abundant from April to June, during the long rainy season and rare or absent from September to March, during the long dry, short rainy and short dry seasons. At Apoma Tapoe, however, only 40 km downstream, they were most abundant in october and November, during the long dry season. Females entered houses to feed, with peak biting activity between 22·00 and 23·00 h, and were observed to rest near the collector for a mean of 7·7 min before and 17·1 min after feeding. No females were found resting by day, in buildings or out of doors. The mean parous rate of 827 females from biting catches was 43·6%. The expected biting rate of females was reduced by 20·3% in a house for six nights after it had been sprayed with DDT wettable powder (2 g/m²active ingredient), and by a mean of 82·6% during seven nights in a camp where the edge of the surrounding forest was sprayed with an ultra-low-volume mist of 95% fenitrothion (1·3 ml active ingredient per metre of perimeter) on the first, third and sixth days.A. darlingilarvae were found at Aseli Kamp in all seasons along the river's edge between water hyacinth plants (Eichhornia) and floating debris, and during the long rains in flooded forest.