Repellent Activity of Essential Oil of Eucalyptus astringens against Rhyzopertha dominica and Oryzaephilus surinamensis

摘要

Insect pests cause serious losses in quantity and quality of the stored products during storage. The lesser grain borer, Rhyzopertha dominica F. (Coleoptera'. Bostrichidae) and the sawtoothed grain beetle Oryzaephilus surinamensis L. (Coleoptera: Silvanidae) are considered as major insect pests in storage in Tunisia and worldwide. The excessive use of synthetic insecticides associated with intensification in agriculture lead to health and environmental problems. This situation requires efforts to find safe, effective and viable alternatives. Natural products are well known to have a range of useful biological properties against insect pests. Recently, research on insecticidal and repellent properties of essential oils has received attention for stored-product protection. Essential oils and extracts from genus Eucalyptus are well known to posses these properties. This study was initiated to evaluate the repellency action of Eucalyptus astringens essential oil against adults of O. surinamensis and R.dominica. Essential oil was extracted by hydrodistillation using Clevenger modified apparatus. GC/MS analysis showed that the main components were alpha-pinene (29.83%), 1,8-cineole (17.29%) and transpinocarveol (3.39%). E. astringens essential oil exhibited a repellent action against the two insects. At the concentration, 0.08 ul/m~2, the repellency percentage was respectively 55% for O. surinamensis and 58.75% for R. dominica after 24 h of exposure.