Chemical Compounds and Bioactivity of Aqueous Extracts of Alibertia spp. in the Control of Plutella xylostella L. (Lepidoptera: Plutellidae)

Abstract

Successive applications of insecticides to control <i>Plutella xylostella</i> L. (Lepidoptera: Plutellidae) have resulted in the emergence of resistant populations of this insect. A novel control measure for this target insect could be the use of botanical insecticides derived from plant tissues. Hence, we experimentally tested aqueous extracts of <i>Alibertia edulis</i> (Rich.), <i>Alibertia intermedia</i> (Mart.), and <i>Alibertia sessilis</i> (Vell.) K. Schum. found in the Brazilian savannah in order to investigate their potential to disrupt the life cycle of <i>P. xylostella</i>. Aqueous extracts of the leaves of <i>A. intermedia</i> and <i>A. sessilis</i> negatively affected the development of <i>P. xylostella</i> in all stages of the life cycle, prolonging the larval stage and causing mortality in the larval or pupal stages. Treatments with <i>A. intermedia</i> and <i>A. sessilis</i> extracts caused the lowest fecundity and the number of hatched larvae. The harmful effects of these aqueous extracts on the life cycle of <i>P. xylostella</i> may be attributable to the flavonoids and other phenolic compounds present in <i>A. intermedia</i> and <i>A. sessilis</i>. These aqueous botanical extracts are low in toxicity when compared to non-aqueous pesticides, and may emerge as an effective approach for control of populations of <i>P. xylostella</i>.