Selectivity of insecticides used in corn culture to eggs of Spodoptera frugiperda (Lepidóptera: Noctuidae) parasites by Trichogramma pretiosum (Hymenoptera: Trichogrammatidae)

This study aimed to evaluate the selectivity of the following insecticides: Cyptrin (cypermethrin), Lannate® (Methomyl) and Ampligo® (Lambda / Clorantraniprole) over the eggs of Spodoptera frugiperda J.E. Smith, parasitized by Trichogramma pretiosum Riley. The experiment was conducted in a bioassay, where the S. frugiperda eggs were exposed to parasitism by T. pretiosum, subsequently the insectcides and some parasitoids at the egg-larva stage were sprayed together over the eggs. The effects of the insectcides on the viability of the eggs were evaluated. The eggs used in the experiment came from the mass rearing held at the Entomology Laboratory of the Instituto Luterano de Ensino Superior de Itumbiara Goiás. The eggs up to 24 hours of age were adhered to a blue cardstock using arabic gum diluted to 80% with water. The cards were exposed to the parasites for a period of 48 hours and kept in a BOD chamber at 25 ± 2 ° C, RH 70 ± 10% and photoperiod of 12 hours standing for 96 hours until the evaluation of the survival of the hosts. The tests applied with the insecticides Cyptrin and Lannate® on parasitism, the insecticides were moderately harmful (class 3) to the eggs viability. Besides, the treatment with the insecticide Ampligo® was slightly harmful (class 2) to the eggs viability. Keywords: Insectcides, S. frugiperda, T. pretiosum, Biological control.