Abstract

Anopheles mosquito larvae were collected from the natural breeding sites in five of the six ecological zones in Nigeria between 2002 and 2004. The larvae were reared to adulthood in a standard insectary. Susceptibility tests were conducted on non - blood fed, 2 to 3-day-old emerged adult female mosquitoes using standard WHO procedures, diagnostic kits and test papers (WHO, 1998). PCR assays were used for the identification of the species and for characterization of the kdr allele. The mosquito samples from all the zones were susceptible to the diagnostic doses of insecticides tested, although, a significant level of resistance was recorded particularly in forest- savanna mosaic and Guinea savanna. However, there was no significant difference in knock down effects of insecticides in all the zones (F_{4, 15}=6.49, P=0.0001). There was a level of correlation between the frequency of the kdr allele and frequency of resistance among the survivor and exposed samples (F = 22.05; P = 0.0037). This may indicate that kdr is associated with resistance in Anopheles mosquito to the tested insecticides. This study forms a baseline data for insecticide resistance status of the local anopheline mosquitoes which can be used to formulate control programmes in Nigeria.

Key words: Anopheles, malaria, pyrethroid resistance, Nigeria.