الملخص

The ethanol extracts of leaves Alianthus altissima, Carrisa grandiflora, fruits of Citrullus colocynthis and aerial parts of Ruta graveolens was tested against fourth instar larvae of the mosquito, Culex pipines molestua Forskal through sublethal doses at the concentrations 5, 10, 15 and 20 ppm. The extracts of C. grandiflora, A. altissima and R. graveolens were prolonged IV-P time with 9.7, 10.3 and 12.8 days at 20 ppm. Whereas, the period shorted to 4.3 days for C. colocynthis in comparison with control 7.3 days. All the plant extracts extended pupal period with significant time, but not more 3.1 days, and 2.1 days for untreated pupae. The reproductive parameters as egg laying hatchability, fecunidity, fertility and sterility percent were showed significant values of emerged adults treated with the plant extracts at IV larval instar.