Larvicidal effects of some Euro-Asiatic plants against Culex quinquefasciatus Say larvae (Diptera: Culicidae).

Methanol extracts of the aerial parts from 62 Euro-Asiatic plant species were tested for larvicidal activity against the mosquito Culex quinquefasciatus Say (Diptera: Culicidae) under laboratory conditions. The fourth larval instar was tested. The extracts of the plants Seseli pallasii and Schisandra chinencis displayed the highest larvicidal activities with LD(50) 6 and 15 ppm, respectively, followed by Arthemisia campestris, Verbena officinalis, and Imperatoria osthruthium with LD(50) 23, 38, and 49 ppm, respectively. The appraised value of LD(50) for two species was between 51-100 ppm; eight species had lethal doses from 101 to 500 ppm, 13 species showed lethal doses from 501 to 1,000 ppm, and 34 species did not show lethal doses for low mortality (LD(50) > 1,000 ppm).