1.) Laboratory tests were conducted using both spraying and dipping methods to reveal the effects of some insecticides on the Hymenopterous parasites within the mummified Macrosiphum avaenae FABRICIUS.
2). The insecticides, which gave more than 80% mortality on the parasites, were Fussol (monofluoroacetamide 10%, dilution 1 : 100), Parathion (methyl-parathion 40%, dilution 1 : 2000), Sumithion (MEP 50%, dilution 1 : 1000) and Hokuthion (γ-BHC 15%, dilution 1 : 300). Dime-thoate 46% (dilution 1 : 1000) and malathion 50% (dilution 1 : 2000) were not detrimental to them.
3). Treatment with either Fussol and parathion killed about 50% of the parasites in larval and pupal stages. But with Sumithion and Hokuthion, it was only 30% and 10% respectively, and the same of the adult stage depended upon the residual effect of the insecticides in question on the adult parasites within the mummified aphids.
4). Judging from the stages of parasites killed by the insecticides, it may be assumed that Fussol and Parathion acted more destructive than the other insecticides.