Extraction of Active Ingredients in Xanthium Sibiricum Patrin and Analysis of Its Insecticidal Activity

To investigate the insecticidal activity of the four kinds of active ingredients which was extracted from Xanthii plants using petroleum ether,benzene,acetone and ethanol solvent respectively,the larvae of Pieris rapae were treated with the extracts.The results showed the four kinds of solvent extracts had less biological activity with the decrease of concentration,and the petroleum ether extract had the best antifeedant rate in the case of low concentration.The antifeed-ant rate of the ethanol extract for 48 h were the best and were 78.53%and 96.24%respectively at the quality concentration 0.08 g/mL and 0.32 g/mL;Contact toxicity activities of acetone extract was the best,and the adjusted mortalities for 24 h and 48 h were 77.78%and 81.48%respectively;the insecticidal toxicity of ethanol extract was the highest,and the adjusted mortalities for 1 d,2 d and 3 d were 73.33%,85.33%and 92.12%respectively.