Direct and indirect effects of Bt corn on the predator Podisus nigrispinus.
This paper aimed to evaluate the direct and indirect effects of Bt corn on the development and reproduction of the predator Podisus nigrispinus (Dallas, 1851) (Hemiptera: Pentatomidae). The experiments were carried out of the Embrapa Agropecuária Oeste, in Dourados, Mato Grosso do Sul, Brazil. To evaluate the direct effect of the Bt corn and non-Bt corn, the predator P. nigrispinus was kept in contact with these plants and fed with pupae of Tenebrio molitor (L.). To evaluate the indirect effects of Bt corn and non-Bt corn, larvae of Spodoptera frugiperda (Smith) were fed with these plants and later offered to the predator. Period of nymphal development, nymphal survival, duration of pre-oviposition and oviposition periods, fecundity and longevity of adults (females and males) were evaluated. Bt corn plants, when in direct contact with P. nigrispinus, did not influence biological parameters of the predator, compared to conventional corn. It was observed a lower duration for the second nymphal instar of P. nigrispinus when this predator was created in larvae of S. frugiperda that had previously been fed on Bt corn plants. Overall, there is no interference with biology and reproduction capacity of the Bt corn plants on the predator.