Studies on the present status of insecticides resistance on mosquitoes using the diagnostic dosages in El-Fayium Governorate, a spot area of malaria in Egypt.

Insecticides susceptibility tests were conducted using the World Health Organization diagnostic doses on the adult and larvae of Anopheles pharoensis and Culex pipiens mosquitoes from Fayium Governorate in Egypt. Insecticides used were malathion, fenitrothion, temephos, diazinon, bromophos and fenthion from organophosphorous group and deltamethrin, permethrin and cypermethrin from synthetic pyrethroid group while propoxur was from carbamate group. Larvae of A. pharoensis were resistant to fenitrothion and susceptible to other insecticides used, while the adults were susceptible to malathion, deltamethrin, fenitrothion and premethrin. Larvae of C. pipiens were resistant to temephos, fenitrothion, bromophos and fenthion and susceptible to malathion, permethrin and diazinon, while the adults were resistant to fenitrothion, permethrin and propoxur and susceptible to deltamethrin, cypermethrin and malathion. These results are important for the success of the control programmes and monitoring the susceptibility status of vectors.