Role of Piper cubeba and Zingiber officinale essential oils in maize weevil, Sitophilus zeamais (Motschulsky) management

Abstract

Uncontrolled and indiscriminate uses of synthetic insecticides in pest management programme cause ozone depletion, neurotoxicity, carcinogenicity, teratogenicity and mutagenesis in non-target animals, and resistance in target animals. These outcomes have diverted attention of researches towards the use of plant volatiles in pest management strategies. In this study, laboratory trial was carried out to evaluate insecticidal properties of tailed pepper, Piper cubeba and ginger, Zingiber officinale essential oils against maize weevil, Sitophilus zeamais (Coleoptera: Curculionidae). Essential oils were isolated and evaluated for repellent, toxic, oviposition inhibitory, developmental inhibitory and feeding inhibitory activities against S. zeamais. In toxicity assay by fumigation method, median lethal concentrations (LC50) of P. cubeba and Z. officinale oils were 0.396 and 0.317 μlcm -3 ; and 0.437 and 0.364 μlcm -3 air respectively when S. zeamais adults were exposed for 24 and 48h. In contact toxicity assay, lethal concentrations (LC50) of P. cubeba and Z. officinale oils were 0.289 and 0.231 μlcm -2 ; and 0.299 and 0.246 μlcm -2 area respectively when S. zeamais adults were exposed for 24 and 48h. AChE activity was reduced when adults were fumigated with sub-lethal concentrations of both oils. Both P. cubeba and Z. officinale oils significantly reduced Role of Piper…