At Charambirá, a village in Istmina county, Department of Chocó, on the Pacific Coast of Colombia, malaria is endemic and is associated with large populations of Anopheles (Kerteszia) neivai, which breed, in water which collects in epiphytic plants of the Bromeliaceae family, very abundant on mangrove trees. Population fluctuation, behavioral and ecological features of adult A. neivai were studied at this locality in an attempt to clarify its role in malaria transmission. Human bait was used in all captures of mosquitoes. Peaks of activity occurred at dawn and at sunset (5:30 to 6:30 and 18:00 to 19:00 hours). Very low biting activity was noted indoors at night and none at all outdoors during the day. The stage of ovarian development of females collected during the peaks of activity revealed two different mosquito populations: one group consisting almost entirely of young individuals seeking a blood meal at sunset and a second group containing almost all older individuals, seeking it at dawn. Seasonal variation indicated that during the months of low rainfall, mosquito populations were sparser, but as rainfall increased the mosquito population also increased. The relation between mosquito populations and cases of malaria is discussed, incriminating A. neivai for malaria transmission in this region.
Anopheles neivai; Ecology, vectors; Malaria