Chemical composition and aphicidal potential of Citrus aurantium peel essential oils

Abstract

Abstract

Aphids are cosmopolitan pests that attack wide range of crops, aphids are also vectors of important plant virus diseases. These pests are developing important resistance against classical chemical insecticides. In this work we studied chemical composition, insecticidal activity of bitter orange peel essential oils and the efficacy of a kaolin based formulation on four aphid species. Chemical analysis by GC-MS of bitter orange oils shows the dominance of limonene on the composition of the oil (67.1%). In vitro insecticidal tests show that fumigant activity is proportional to the concentrations used. At a dose of 33.33 µl / L air and 24h exposure time, essential oils cause 74% mortality in Acyrtosiphon pisum Harris and Rhopalosiphum padi Scop, 60% in Aphis fabae L. and 54% in Macrosiphum euphorbiae Thomas. Calculated LC ₅₀ values vary between 16.12 µl / L air for A. pisum and 31.27 µl / L air for A. fabae. In vivo application of the formulation based on essential oils of bitter orange on infested bean plants show 72.4% mortality on Aphis fabae. This shows the importance of essential oils as potential alternative to chemical pesticides.