Comparison of Resistance Status to Permethrin (Pyrethroid Insecticide) in Culex pipiens pipiens (Diptera: Culicidae) Collected from Three Localities of Tunisia

Conventional insecticides are among the most popular chemical control agents against mosquitoes. Our study aimed to evaluate the resistance status to permethrin (pyrethroid insecticide) in Culex pipiens pipiens (Diptera: Culicidae) from Tunisia. For this study, three samples of C. p. pipiens mosquitoes were collected from Northern and Southern Tunisia between 2003 and 2005. Early third and late fourth instar larvae were morphologically identified and used for bioassays. All samples were resistant to permethrin and a large variation ininsecticide tolerance was observed between samples. The RR50 values ranged from 3.01 in El Fahs to 39.3 in Sidi Hcine. Resistance to pyrethroid and dichloro-diphenyl-trichloroethane (DDT) insecticides were negativelycorrelated, indicating a sensitive voltage-gated sodiumchannel (CNaVD) in the most resistant population. The use of synergits showed the involvement of CYP450 in the recorded resistance to permethrin in Sidi Hcine. Results were discussed in relation to previous studies and mosquito control. Data on resistance insecticide were provided to serve as a base for further resistance management interventions.