LC₅₀'s of oxymal and malathion to male Catolaccus grandis (Burks) were 513 and 57 fold greater than LC₅₀ to female parasites, respectively. LC₅₀'s of profenofos to female parasites was 13 fold greater than LC₅₀ of male parasites. Endosulfan was comparatively nontoxic to both sexes. We were unable to select for resistance to malathion against either sex during 16 months.