Lethal and sublethal effects of essential oils from Piper capitarianum Yunck and Piper krukoffii Yunck on Plutella xylostella L.

Abstract

Plutella xylostella (L.) is responsible for considerable vegetable crop losses in the metropolitan region of Manaus, Brazil. In recent decades, essential oils have been investigated as an alternative to synthetic insecticides. The genus Piper is widely distributed in Amazonia and essential oils from these plants have insecticidal properties. This study describes the chemical composition of the essential oils from Piper capiterianum and Piper krukoffii as well as the lethal and sublethal effects on P. xylostella. The phytotoxicity of the oils on the host plant was also evaluated. Globulol was the major constituent of the P. krukoffii oil and o-cymene was the major constituent of the P. capitarianum oil. The oil from P. capiterianum exhibited greater toxicity to larvae and eggs. This oil also presented greater repellant action, feeding deterrence and mild phytotoxicity to the host plant (Brassicae oleraceae). The findings suggest that this oil can be used in the preparation of a formulated insecticide for the management of P. xylostella in different development phases. However, further studies are needed to evaluate the effect of this oil on crops under field conditions as well as non-target organisms and determine the cost-benefit ratio of a product formulated with P. capitarianum oil.