Study on the Insecticidal Activity of Pedicularis spicata Pall on Wolfberry Aphis

[Objective] The aim of the study was to supply foundation for the exploitation and utilization of Pedicularis spicata Pall and the research on its active components.[Method] Topical application was used to study the insecticidal activities of the ethanol extracts and 5 kinds of extracts with petroleum ether,chloroform,ethyl acetate,n-butanol,aqueous as extractants from P.spicata on wolfberry aphis.[Result] 15.30% of insecticidal active components from P.spicata was extracted with 95% ethanol as extractant and material-liquid ratio of 1∶10.The corrected mortality of wolfberry aphids increased along with the increment of ethanol extracts concentration and the extending of treating time.When the ethanol extract was at 50.00 mg/ml,the corrected mortality after 48 h reached 96.38% and the regression equation of virulence was y=2.220x +2.859.The insecticidal activities of 5 extracts on wolfberry aphids in order were petroleum ether n-butanol chloroform ethyl acetate water and the corrected mortality of petroleum ether extracts after 48 h reached 96.38%.[Conclusion] The ethanol extracts from P.spicata had better insecticidal effect on wolfberry aphids with LC50 being 9.21 mg/ml after 48 h.Its main insecticidal active components were weak polar matter and mainly distributed in the polarity range of petroleum ether.