Effect of some plant extracts on the Culex pipiens molestus Forskal larvae

A preliminary study was conducted to investigate the effects of the extracts of eight plant species collected from Ninavah governorate on the second instar of larval stage of Culex pipiens molestus Forskal. Three out of the eight plant extracts Azadirachta excelsa Jack, Cleome glaucescens Dc. and Quercus infectoria DL. caused 100% mortality of larvae at a concentration of 200 μg/mL after 3days of treatment. The LC50 values were less than 150μg/mL (62.5μg/mL-140μg/mL). The A. excelsa leave extract showed mortality on larval and pupal at low concentrations 40μg/mL- 10μg/mL also affected in delaying larval development. The extracts of Achillea santolina L., Ammi majus L. and Ricinus communis L. caused high mortality to the larvae after 7 days of treatment, but the Datura stramonium L. and Carum petroselinum Benth extracts did not cause any mortality to the larvae at the same date.