Baseline entomological data for a pilot malaria control program in Equatorial Guinea.

Entomological studies conducted on the island of Bioko and the mainland province, Río Muni, in Equatorial Guinea provided baseline data for a pilot malaria control program. The main species collected resting in houses at low density were Anopheles gambiae s.l. Giles and Anopheles funestus Giles. An. gambiae s.l. density increased during the rainy season, whereas An. funestus populations remained stable during both dry and wet seasons. Both species tended to be endophilic and were not collected resting or biting outdoors. Overall, delayed sporozoite rates were about 10% for both species and were highest in the dry season. An. gambiae s.l. from the mainland showed resistance to 4% DDT, but the island population was still susceptible. All populations were completely susceptible to 5% malathion and 0.025% deltamethrin.