Comparative Efficacy of Essential Oils Extracted from the Fruits and Leaves of Eucalyptus globulus in the Control of a Stored-Product.

Abstract

This study demonstrates the bioinsecticidal potential of essential oils extracted from the leaves and fruits of Eucalyptus globulus against Rhyzopertha dominica, a major pest of stored cereals.A series of laboratory bioassays were conducted to evaluate both toxicity (via ingestion and fumigation) and repellent effects of the essential oils. The results demonstrated significant dosedependent mortality in both ingestion and fumigation assays. Among the tested plant parts, leaves-derived essential oil exhibited the highest toxicity, likely due to a higher concentration of bioactive compounds, particularly 1,8-cineole, known for its strong insecticidal properties.Repellency tests conducted using the preferential zone method revealed that the oil extracted from the fruits of E. globulus displayed superior repellent activity against adult R. dominica compared to that of the leaves. This enhanced repellent action is attributed to the distinct volatile profile of the fruits, which may include higher proportions of olfactory-disruptive compounds.These findings underscore the dual mode of action (toxicity and repellency) of E. globulus essential oils and support their potential application as eco-friendly alternatives to synthetic insecticides for the protection of stored cereals.