Insecticide susceptibility of A nopheles coluzzii and A nopheles gambiae mosquitoes in I badan, Southwest N igeria

The emergence of insecticide resistance in A nopheles ( D iptera: C ulicidae) mosquitoes has great implications for malaria control in N igeria. This study aimed to determine the dynamics of insecticide susceptibility levels and the frequency of knock‐down resistance ( kdr ) mutations ( L1014F ) in wild A nopheles coluzzii C oetzee & W ilkerson sp. n. and A nopheles gambiae G iles from the O joo and B odija areas of I badan, in southwest N igeria. Insecticide susceptibility to pyrethroids, organophosphates, carbamates and organochlorines was assessed using World Health Organization ( WHO ) bioassays. A subset of the mosquitoes exposed to pyrethroids and DDT was used for species and molecular form identification; kdr genotyping was determined using the T aq M an real‐time polymerase chain reaction assay. The mosquitoes were resistant to pyrethroids and DDT but completely susceptible to organophosphates and carbamates. Bodija samples ( n = 186) consisted of A n. gambiae (91.4%) and A n. coluzzii (8.1%) and included one A n. coluzzii / A n. gambiae hybrid specimen. All mosquitoes screened in O joo ( n = 26) were A n. gambiae . The 1014F kdr mutation was detected at frequencies of 24.5 and 5.8% in B odija and O joo, respectively. No correlation was observed between kdr genotypes and resistance phenotypes. The results indicate that metabolic resistance probably plays an important role in the development of resistance and highlight the need to implement insecticide resistance management strategies.