Insecticide susceptibility status of Culex quinquefasciatus [Diptera: Culicidae] in Umudike, Ikwuano LGA Abia State, Nigeria

Abstract

Larval and pupal stages of Culex quinquefasciatus mosquito were collected from different points within Umudike, Abia State, Nigeria, and reared to adulthood in the laboratory. The adults that emerged were tested on 4% DDT (Organochlorines); 0.1% bendiocarb (Carbamates); 0.25% Primiphos-methyl (Organophosphates); and 0.05% Deltamethrin (Pyrethroids) procured from National Arbovirus and Vector Research Institute Enugu. Twenty sugar fed female Culex quinquefasciatus mosquitoes aged 3-5days were used for the bioassay which was replicated four times with two control. Knockdown was recorded at five minutes, and then 10 minutes interval for 1 hour and then maintained for 24hrs post-exposure on 7% sugar solution, after which a final mortality was recorded. The Knockdown times (KDT50 and KDT90) were determined by Probit analysis. Culex quinquefasciatus was resistant to all the insecticides, with 24hours post exposure percentage mortalities of 10.48, 39.20, 0.00, and 10.15 in DDT, bendiocarb, primiphos-methyl and deltamethrin respectively.