[Bio-ecological characteristics of Anopheles gambiae s.s. in irrigated rice fields of central Côte d'Ivoire].

Abstract

This longitudinal entomological survey was conducted between September 2008 and September 2009 in the villages of Abokro and Yaokoffikro located in an irrigated rice farming area of central Côte d'Ivoire. The purpose was to investigate the bio-ecological characteristics of Anopheles gambiae s.s. during the gonotrophic cycle. In both villages, adult mosquitoes were captured in 72 light traps, collected on humans subjects at a rate of 72 man-night from 6 p.m. to 6 a.m., and knocked down using pyrethroid spray inside 60 sentinel houses in the early morning. A total of 10,312 adult mosquitoes were collected in Abokro and 7,662 in Yaokoffikro. Anopheles was the dominant genus at both locations. Light traps were three times more efficient in Abokro than in Yaokoffikro. In both places, An. gambiae s.s. biting rates increased gradually up to a peak observed between midnight and 1 a.m. In Abokro, most An. gambiae s.s. were collected inside sleeping rooms. The endophagic rate and indoor resting density was 67.4% (n = 4798) and 14.9 females per bedroom per night, respectively, in Abokro as compared to 49.3% (n = 6775) and 2.9 females per bedroom per day, respectively, in Yaokoffikro.