eng Oriental Scientific Publishing Company Biosciences Biotechnology Research Asia 0973-1245 2016-02-06 5 1 115 120 6522 article Khalid M. Al-Ghamdi 1 Jazem A. Mahyoub 1 Mostafa S. Saleh 1 Department of Biological Sciences, Faculty of Science, King Abdulaziz University Mosquito Research Lab., Jeddah (Saudi Arabia) Susceptibility levels of Culex pipiens L. mosquito larvae to the conventional insecticides Actikil and Pesguard as well as non-conventional ones the insect growth regulator Dudim, the bioinsecticide Bacilod and the plant extract Neem oil were determined. Taking LC50 values (concentration which to kill 50% of larvae) into consideration, mosquito larvae of C. pipiens were more susceptible to the pyrethroid Pesguard (0.048 ppm) than the organophosphate Actikil (0.052 ppm) and the biocide Bacilod (0.13 ppm) by about 1.1 and 2.7 folds, respectively. According to IC50 values (concentration which to inhibit the emergence of 50% of adults), the IGR Dudim (0.0003 ppm) proved to be more effective against mosquito larvae of C. pipiens than the plant extract Neem oil (70 ppm). Variation in the susceptibility status of the present mosquito larvae may be attributed to the differential mode of action of the compounds tested and its effective concentrations. On the other hand, different levels of potentiation and additive effects were obtained when the present compounds were applied jointly against mosquito larvae of C. pipiens. https://www.biotech-asia.org/vol5no1/evaluation-of-some-conventional-and-non-conventional-insecticides-against-mosquito-larvae-of-culex-pipiens-l/ Mosquito larvae; Susceptibility status; larval bioassay; joint action