The aim of this work was to evaluate the toxicity of the insecticides acetamiprid (0.05 g L-1 a.i.), chlorfenapyr (0.12 g L-1 a.i.), imidacloprid (1.16 g L-1 a.i.), thiacloprid (0.48 g L-1 a.i.) and thiamethoxam (0.05 g L-1 a.i.) to Trichogramma pretiosum, in different immature stages. Eggs of Anagasta kuehniella glued in blue paper cards were offered to females of T. pretiosum for 48 hours. After the parasitization, the eggs were treated by dipping the cards into the chemical solutions or in water for five seconds after they reached the egg-larval, prepupal and pupal stages. The bioassays were carried out under controlled conditions, at 24±1ºC, RH of 70±10% and 12 hours of photophase. Both chlorfenapyr and imidacloprid reduced in 76.0% and 64.4%, respectively, the emergence of individuals of the F1 generation of T. pretiosum. No insecticide affected the sex ratio of the F1 generation of this parasitoid. Chlorfenapyr reduced in approximately 50% the parasitization rate of individuals of the F1 generation. Both acetamiprid and thiamethoxam were harmless to T. pretiosum, so that they can be used for the control of pests in tomato crop with this parasitoid.
parasitoid; tomato; pesticides; selectivity
