Effect of chemical insecticides used in tomato crops on immature Trichogramma pretiosum (Hymenoptera: Trichogrammatidae)

The effects of the chemical insecticides acetamiprid, lufenuron, imidacloprid, novaluron, triflumuron, and pyriproxifen on the developmental stages of Trichogramma pretiosum were evaluated. Eggs of Anagasta kuehniella glued on blue paper cards were offered to T. pretiosum females for 24 h. After parasitization, the eggs were treated by dipping the cards into the insecticide solutions or in water for 5 s after they had reached the egg-larval, pre-pupal, or pupal stages. The application of pyriproxifen to T. pretiosum during its egg-larval period was slightly harmful to the parasitization capacity of F-1 generation females and the emergence rate of F-1 and F-2 generation adults. When applied to T. pretiosum in the egg-larval period, acetamiprid was slightly harmful to the parasitization capacity of the F-1 generation females of T. pretiosum. When applied to T. pretiosum in the pupal stage, acetamiprid was slightly harmful to the parasitization capacity of F-2 generation females. When applied during the egg-larval period, imidacloprid was slightly harmful to the parasitization capacity of T. pretiosum females of the F-1 generation. Lufenuron applied on T. pretiosum in the pupal stage was slightly harmful to the parasitization capacity of the F-2 generation females. The insecticides novaluron and triflumuron, when applied during the immature stages to T. pretiosum, were harmless to its F-1 and F-2 generations.