Estratégias de controle de Spodoptera frugiperda (Smith, 1797) (Lepidoptera: Noctuidae) utilizando inimigos naturais

Abstract

Corn crops are affected by pests such as Spodoptera frugiperda, which is controlled with chemical insecticides. Biological control is an alternative, using natural enemies such as the predators Euborellia annulipes and Marava arachidis, and the fungus Metarhizium anisopliae. Therefore, the objectives of this study were: to evaluate the predation and handling time of E. annulipes and M. arachidis on S. frugiperda associated or not with M. anisopliae and the survival of predators after consumption of the pest associated with the fungus. Jaboatão and hybrid corn were planted in a greenhouse and infested with the pest and predators. 5 g of the fungus was applied, diluted in 50 mL of distilled water. The consumption analysis was performed using a generalized linear model with binomial distribution. The handling time was subjected to analysis of variance and the means compared with Tukey. Survival curves were estimated using the log-rank method. The results showed that there was no difference between the corns in terms of consumption rate. Regarding handling time, the hybrid treatment was significant, with less time on the IV instar and more time on eggs/I instar. There were no differences in the insect factor. In Jaboatão, no factor was significant. Predators consumed mainly early stages, even when associated with the fungus. The fungus did not affect predator preference. M. arachidis was more effective. In the hybrid, there was greater consumption and the fungus did not affect predator survival. Therefore, predators are promising and M. arachidis is as effective as E. annulipes.