Chemical characterization and fumigant activity of Citrus limon peel and leaf essential oils against Ectomyelois ceratoniae and Ephestia kuehniella (Pyralidae)

This research investigated the chemical profile and fumigation-based insecticidal potential of essential oils obtained from Citrus limon peels and leaves against the two major storage pests, Ectomyelois ceratoniae and Ephestia kuehniella. The oils were recovered through hydrodistillation and their composition was determined by gas chromatography–mass spectrometry. Fumigant toxicity was assessed against eggs, larvae, and adults under controlled laboratory conditions. Peel essential oil was mainly composed of limonene (52.68%) and neral (13.32%), whereas the leaf oil was characterized by neral (30.75%), neryl acetate (22.05%), and nerol (10.18%). Both oils exhibited dose-dependent toxicity against all developmental stages. The leaf oil showed higher fumigant toxicity to adults, with LC50 values of 1.1 μL/L air for E. ceratoniae and 0.99 μL/L air for E. kuehniella, compared to 2.7 and 2.4 μL/L air, respectively, for the peel oil. For the larvae, the LC50 values for the essential oil from the fruit peel were 166.28 and 164.6 μL/L air for E. ceratoniae and E. kuehniella, respectively. The essential oil from the leaves was 129.3 and 127.4 μL/L air for E. ceratoniae and E. kuehniella, respectively. Both oils significantly reduced egg hatchability, reaching 14.8% (leaf) and 24.4% (peel) at the highest concentration. These findings demonstrate that C. limon essential oils, especially those derived from leaves, possess strong fumigant, larvicidal, and ovicidal properties and support their potential use as botanical agents in stored-product pest management strategies.