A mosquito survey of Thomo village, Northern Province, South Africa, with special reference to the bionomics of exophilic members of the Anopheles funestus group (Diptera: Culicidae)

Thomo village, in the Northern Province of South Africa, experiences low-level malaria transmission during the summer months. All houses in the village are sprayed regularly with DDT and no mosquitoes are found resting indoors. In 1987-1989 mosquito surveys were undertaken to establish the anopheline species composition and their outdoor biting and resting preferences. Exophilic members of the Anopheles funestus Giles group were the most abundant species, with 85.8 % of the total catch (n = 23 252) belonging to this group. However, of those species attracted to humans, An. coustani Laveran was the most abundant at 70.1 % (n = 2994) followed by the An. funestus group at 28.1 %. Both An. coustani and the An. funestus group were collected within the first two hours after sunset throughout the year. Adults of the Anopheles gambiae Giles complex were collected from landing-catches and resting outdoors (n = 245) and from larval collections (n = 225). Of these, 155 and 164 respectively were identified electrophoretically as An. quadriannulatus (Theobald). No An. arabiensis Patton were recorded.