RESIDUAL FOLIAR TOXICITY OF 4''-EPI-METHYLAMINO-4''-DEOXYAVERMECTIN B1 HYDROCHLORIDE (MK-243) AND SELECTED COMMERCIAL INSECTICIDES TO ADULTHYMENOPTEROUS PARASITES, PTEROMALUS-PUPARUM (HYMENOPTERA, PTEROMALIDAE) AND COTESIA-OROBENAE (HYMENOPTERA, BRACONIDAE)

The residual contact toxicity of MK-243 (4 ''-epi-methylamino-4 ''-deo xyavermectin B1 hydrochloride), permethrin, esfenvalerate (pyrethroids ) and methomyl (carbamate) to 2 parasitic hymenoptera, Cotesia orobena e (L.) (Braconidae) and Pteromalus puparum (L.) (Pteromalidae), in bro ccoli was evaluated. Each parasite was caged on treated broccoli leave s at various times after the plants had been sprayed in the field. Met homyl was the only insecticide consistently toxic to P. puparum up to 1 d after the leaves were sprayed, but this compound had no affect 3 d after treatment. MK-243 and the 2 pyrethroids had no significant effe ct on P. puparum. The effect of the insecticides on C. orobenae was di fferent and less consistent. Esfenvalerate caused significant mortalit y of C. orobenae, but methomyl and permethrin killed a significant num ber of parasites in only 1 of the 2 trials. MK-243 was not toxic to C. orobenae in our studies.