Fumigant insecticidal activity of plant essential oils against pest blister beetle Epicauta atomaria (Germar) (Coleoptera: Meloidae)

Abstract

Epicauta atomaria is a phytophagous insect pest of agricultural crops controlled through the application of synthetic insecticides that cause serious human health and environmental damage. Bioinsecticides formulated from essential plant oils are suitable as an alternative to synthetic insecticides in the control of pest insects. For this reason, the objective of this work is to determine the fumigant insecticidal activity of a screening of plant essential oils against E. atomaria and determine the chemical composition of the essential oils with greater toxicity. The fumigant insecticidal activity was evaluated at different concentrations; the chemical composition of the essential oils with greater toxicity was determined by gas chromatography mass spectrometry. Mentha spicata and Salvia rosmarinus essential oils showed strong fumigant activity against E. atomaria with LC50 values of 21.7 and 23.3 μL/L air, respectively, followed by Laurus nobilis and Pascalia glauca essential oils showing strong fumigant activity with LC50 value of 32.8 μL/L air in both cases. The major components identified in the M. spicata essential oil were pulegone (55.08%) and isopulegone (12.57%) and those in the S. rosmarinus essential oil were camphor (19.42%), 1.8-cineole (18.72%), α-pinene (15.87%) and camphene (11.88%). In conclusion, M. spicata, S. rosmarinus, L. nobilis and P. glauca essential oils could be considered as components in bioinsecticide formulations for future integrated pest management (IPM) programmes.