Abstract
Failure to find out promising new compounds of insecticides has led many researchers back to biodiscovery studies is the search for new and economically viable alternatives. The present work was conducted by exposed 3rd larval instar c Culex quinquefasciatus to different concentrations from the two plant extracts; Artemisia herba alba and Matricari. chamomilla to evaluate their efficacy by determined LC50 after a period of exposure for 24 hours following the standard. World Health Organization (WHO) insecticide susceptibility methodology. The results indicated that M. chamomilla was more effective than A. herba alba on both larval and pupal stages after 24 hours. Several effects such as; blocking of metamorphosis and ecdysis, inhibition of adults' emergence, morphogenetic malformations were recorded in larvae pupae and adults stages. Such malformation and gross morphological features changes were quite similar to those reported for certain insect growth regulators.