Background: West nile virus (WNV) can cause a fatal disease in humans and WNV is mainly transmitted to people through the bites of infected mosquitoes. Vector control is a very important part of the current global strategy for the control of mosquito-associated diseases and insecticide application is the most important component in this effort.Objectives: We here conducted a study of
Culex pipiens resistance towards several insecticides regularly used in the city of Tehran, Iran.Materials and Methods: Adult females reared from field-caught larvae from southern part of
Tehran and lab strain reared in the insectary of
Tehran University of Medical Science were determined for resistant status by exposing to 4% DDT, 0.1% bendiocarb, 0.1% propoxur, 1% fenitrothion, 0.05% deltamethrin, 0.75% permethrin, 0.05% lambda-cyhalothrin, 0.5% etofenprox, 5% malathion and 0.15% cyfluthrin papers using the standard WHO susceptibility test and examined lethal times (LT50 and LT90) and knockdown times (KT50 and KT90).Results: Results clearly showed resistance development of Cx. pipiens against tested insecticides. mortalities of Cx. pipiens were less than 90% with high resistance, low knock down rate and knock down time (50%) observed against mentioned insecticides. mosquitoes from the southern parts of
Tehran presented higher level of resistance pattern in comparison to those from insectary. DDT and malathion showed the most and least lethal time (LT50) values for the field strain, respectively, while DDT and deltamethrin demonstrated the most and least lethal time (LT50) values for the lab strain of Cx. pipiens, respectively. The results of the knockdown test showed that DDT and deltamethrin had the most and least knockdown times (50%) for the field strain, respectively, while DDT and lambda-cyhalothrin had the most and least knockdown times (50%) for the lab strain, respectively.Conclusion:
Resistance to mentioned insecticides in Cx. pipiens is widely distributed in southern part of Tehran. Regularly implementation of susceptibility test in Cx. pipiens mosquitoes will help local public health authorities to developed new and better control strategies. Early discovery of insecticide resistance will help to set proper actions in delaying mosquito resistance phenomenon.