Abstract
The present study was planned to use the technique of Polymerase chain reaction (PCR) to detect the virus of dengue fever in mosquito females of Aedes aegypti (L.) and A. caspius (Pallas). The results indicated that all samples tested for virus of dengue were found negative (-) except one sample of A. aegypti which was positive (+). On the other hand, susceptibility levels of mosquito larvae of field strains of A. aegypti, which is the vector of dengue fever, to some insecticides currently in use in Jeddah governorate were determined. Taking LC50 values (concentration which to kill 50% of mosquito larvae) into consideration, mosquito larvae of A. aegypti proved to be more susceptible to Bactilarvae (0.012 ppm) than Safroten (0.020 ppm), Temephos (0.032ppm), Solfac (.039 ppm) and Icon (0.047ppm), respectively. In other words, Bactilarvae proved to be more effective against A. aegypti mosquito larvae than Safroten, Temephos, Solfac and Icon (1.6, 2.66, 3.25 and 3.92) respectively.