The effect of tau-fluvalinate and lambda-cyhalothrin on two parasitic species of Phradis spp. [Hymenoptera, Ichneumonidae, Tersilochinae]

The effect of two pyrethroid ester insecticides, as well as their concentration, on the insect survival were studied along with the dynamics of the insect intoxication, as dependent on the application rate of the chemicals. The laboratory tarsal plate test, carried out in May 2006, was based on commercial formulations of τ-fluvalinate and λ-cyhalothrin instead of pure a.i. The study aimed at producing practical recommendations about the reduction of the application rate in the chemical protection of the oil seed rape (OSR) against the pod and the stem weevils and against the pollen beetle. The results suggest that the application rate reduction of τ-fluvalinate does not alter considerably the survival of the tested insect parasitoids, whereas in case of λ-cyhalothrin it is accompanied by an increase in the insects`survival.