Insecticidal activity of Psychotria spp., Vatairea spp. and Acosmium spp. on the biological parameters of Plutella xy-lostella L. 1758 (Plutellidae: Lepidoptera).

Abstract

In recent years, several botanical species have been tested to determine their ability to reduce the damage caused by Plutella xylostella L. (Lepidoptera: Plutellidae) in brassica crops. Considering the insecticidal potential demonstrated by many botanical species, the effects of the aqueous extracts of Psychotria leiocarpa Cham. & Schltdl, Psychotria deflexa DC., Acosmium subelegans (Mohlenbr.) Yakovlev and Vatairea macrocarpa (Benth.) Ducke by infusion and maceration on the biological parameters of P. xylostella were evaluated. All extracts reduced P. xylostella larval duration and caused larval and egg mortality. In the larvae, the extracts resulted in 70% mortality. In addition, the botanical extracts affected the survival of P. xylostella eggs. The extracts of P. leiocarpa and P. deflexa, prepared by infusion, delayed the emergence of adults, while the extract of V. macrocarpa reduced pupal survival. The longevity of adults was also influenced by the extracts, where the maceration of V. macrocarpa and P. deflexa and infusion of A. subelegans reduced the longevity of P. xylostella females and the maceration of V. macrocarpa and P. leiocarpa reduced the longevity of P. xylostella males. We conclude that the studied extracts were toxic to P. xylostella, especially in the reproduction, of diamondback moth. Consequently, the botanical extracts reduced the number of individuals of the next generation.