Vector control and genetic structure of Anopheles gambiae S.l. populations revealed by the Kdr mutation in some agro- ecological areas of high malaria incidence in Benin (West Africa)

Abstract

The resistance of An. gambiae s.l. populations to pyrethroids led by the L1014F Kdr mutation is a scientific evidence in Benin. Knowledge of the genetic structure of Anopheles populations in high-incidence areas is becoming imperative to identify the evolutionary forces implicated. The study was conducted in 3 agro- ecological zones, each with specific characteristics. The surveyed localities are from the main eco-epidemiological areas of Benin where malaria transmission is high. Thus, larvae of An. gambiae s.l. were collected and reared to adulthood at the insectarium of the Centre de Recherche Entomologique de Cotonou. Species identification of the adult female mosquitoes were performed in a morphological way and, through PCR. The genetic structure of each population was determined via the L1014F resistance allele of the Kdr.Of the 557 specimens of An. gambiae s.l. sampled in the study area, 381 were An. gambiae s.s., 174 An. coluzzii and 02 An. arabiensis. Overall, the L1014F Kdr frequency was high (p < 0,05) for all populations of An. gambiae s.l. No statistical difference (p > 0.05) was observed for the distribution of L1014F which appears to be homogeneous within the different species populations analysed by agro-ecological zone. Heterozygous deficiency is general in An. gambiae s.s. and An. coluzzii populations in the different agro-ecological zones. From low genetic differentiation in all An. gambiae s.s. populations, it increased to moderate to significant in Bar Land Zone and Northen Cotton Zone for An. coluzzii, respectively.