Insecticidal Activities of Four Citrus Essential Oils on the Bean Weevil Longevity, Acanthoscelides obtectus Say. (Coleoptera: Bruchidae)

Abstract

The study focuses on the evaluation of the insecticidal potential of Citrus limonum, C. sinensis, C. paradisi and C. aurantium as bioinsecticides to reduce the damage caused by the pest Acanthoscelides obtectus on white bean crops. The toxicity of essential oils extracted from 04 species of Citrus was tested under laboratory conditions at 30°C and 70% RH by three modes of action contact, inhalation and repulsion on the A. obtectus adults longevity. The results obtained for the parameter studied indicate that the essential oils extracted from C. limonum, C. sinensis and C. paradisi exert a more or less significant toxicity towards the insect pest for all the tests carried out, however the oil extracted from C. aurantium is the most effective since the A. obtectus longevity decreases from the lowest dose of 2μl and is 100% at 6μl. Regarding the inhalation test, the fumigation effect is very important from the lowest doses achieved with C. aurantium essential oil, on the other hand the other oils have only shown significant effectiveness at the highest doses. The results of the repellency test revealed that C. aurantium essential oil is the most repellant compared to the other essential oils tested