With new botanical insecticide,we studied the insecticidal activity of extracts from leaves of Juglans mandshurica on Harmonia axyridis and Trichogramma dendrolimi.We evaluated the toxicity of alcohol extractive with different concentrations on two insect natural enemies in the laboratory with the distilled water as control.The extract from J.mandshurica had significantly contact toxicity against H.axyridis and T.dendrolimi.When H.axyridis was treated with the concentration of2.039 5 g / L for 48 h,the corr...