Abstract:
Insecticidal activity of Daphne tanutica, a local endemic plant from Qinghai-Tibet plateau, was first reported in this paper. The air-dried and powdered plant was extracted with methanol, acetone, ethyl acetate, chloroform, benzene and petroleum ester, and the results showed that foe extractive rate in methanol was the largest (22. 34% ), and the smallest (2. 21% ) in petroleum ester. The crude extracts of former five solvents were proved to possess strongly antifeeding effect on the 3rd instar larvae of tobacco cutworm, Spodoptera litura, through the preliminary bioassay with AFC50s of 108. 72, 111. 69, 102. 14, 71. 15 and 65. 51 g dried powder/L. At concentration of 500 g dried powder/L, antifeedant effect of the petroleum ester extract against the tested insects was 62. 31 %. Therefore benzene was the most effective extracting solvent.