Study on bionomics of principal malaria vectors in Kratie province, Cambodia.

ABSTRACT

A cross-sectional study on bionomics of malaria was carried out in Kamlek village, Snuol rubber plantation, Kratie Province where the population had a high prevalence of malaria. Mosquitos were collected monthly between April to September 1998 from 18.00 hr to 6.00 hr by human bait and animal bait. Survey for larva breeding places was also performed. A total of 13 species of Anopheline mosquitos was collected, manly Anopheles philipinensis, An. aconitus, An. annularis, Ain. barbirostris, An. hyrcanus gr, An. jamesii, An. kawari, An. tesselatus, An. umbrosus and An. vagus. They were in various densities with the latter species being the most abundance. Among the vector species. An. maculatus was the most commonly collected with a density of 0.55 per man per night and peak biting was between 20.00 hr and 21.00 hr. The density of An. minimus and An. dirus were 0.11 and 0.74 per man per night with the peak biting time 24.00-01.00 hr and 20.00-21.00 hr respectively. Observation of host preference and feeding habit revealed An. maculatus to be exophagic, anthropophilic and 20 endophilic while An. minimus was both endophilic and exophagic and anthropophilic. An. dirus was endophilic and anthropophilic, these three species were not found positive for malaria infection. However, due to the limited time of survey and an exceptionally low rainfall in the rainy season, an inadequate sample was obtained for analysis. Therefore further investigation is required for at least a year for more information.