Species of Anopheles (Culicidae, Anophelinae) in a malaria-endemic area, Maranhão, Brazil

Abstract

Introduction The study of the seasonal fluctuation, nocturnal activity, relative abundance and the richness of Anopheles species in anthropic environment is essential to the understanding of the their bioecology and to the surveillance program of malaria control. Methods The Anopheles species were studied from 6 P.M. to 6 A.M., once a month, for one year, from October 1996 to September 1997, in the municipal district of Raposa, of the São Luís island, Maranhão state. The basic method was the capture of female specimens on human baits in peri and intradomicile sites by means of aspiration tube and guided luminous focus. Results A total of 1.407 specimens were collected and distributed as follow: Anopheles aquasalis (82% of the sample), Anopheles galvaoi (10,2%), Anopheles albitarsis (6,4%), Anopheles evansae, Anopheles nuneztovari, and Anopheles triannulatus davisi (the last three represented together 1,4%). The anophelines occurred all year round, mainly in the rainy period, being more frequent in the intra (75,3%) than in the peridomicile site (24,7%), showing a clear preference to suck blood in the evening. Conclusion The behavioural variation of Anopheles shows that the different species are becoming adapted to closeness to human habitations, in the rural zone of the São Luis island.