Bioatividade de extratos aquosos de trichilia spp. sobre spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) em milho

Abstract

Spodoptera frugiperda (J.E. Smith) is the most important pest of maize. The high number of chemical applications necessary to its control has lead to some problems as resistance development and environmental contamination. The use of insecticide plants is an alternative to control this pest. The efficacy of aqueous extracts of leaves and twigs from six Trichilia species (T. casaretti, T. catigua, T. clausseni, T. elegans, T. pallens and T. pallida) against S. frugiperda was evaluated in laboratory being compared with the aqueous extract from Azadirachta indica (neem) seeds. Maize leaves immerged in each extract were dried and then given to the first instar larvae. The survival and larval weight were evaluated at the fifth day after treatment application. Concerning the six Trichilia species tested, at least one of their structures (twigs or leaves) affected the insect development. The extracts from leaves of T. pallens caused mortality similar to neem extract; the extracts from twigs of T. pallens, and twigs and leaves of T. pallida, although less efficient, also reduced the S. frugiperda larval weight and survival.