Insecticidal and repellent impacts of Lavender and Tea tree essential oils on different stages of Greater Wax Moth, Galleria mellonella L. (Lepidoptera: Pyralidae).

The greater wax moth (Galleria mellonella) poses a significant challenge to apiculture by damaging stored wax combs, affecting honeybee product quality, and potentially transmitting diseases. Addressing this issue requires developing efficient control methods to safeguard the vitality and productivity of apiculture. The current study investigates the insecticidal activity of tea tree (Melaleuca alternifolia) and lavender (Lavandula multifida) essential oils on the eggs, larvae, and pupae of Galleria mellonella exposed to different oil concentrations for 48 hours under laboratory conditions. The moth repellent effect and acetylcholinesterase activity of treated larvae were also assessed. Laboratory assays demonstrated the safety of these essential oils for honeybee workers. Results revealed a highly significant impact of the tested oils on various biological traits of the wax moth, including egg hatching, pupation, adult emergence, and some morphological abnormalities, all of which increased with higher oil vapor concentrations. Notably, exposure to 500 µl concentrations of tea tree and lavender oils reduced the egg hatching rate to 9.84% and 4.16%, respectively, and adult emergence from exposed pupae to 35.55% and 36.61%. Moreover, 66.59% and 73.68% of larvae affected by tea tree and lavender oils, respectively, were lost before adult emergence. The essential oils also exhibited effective repellent activity at a concentration of 500 µl/L air. Furthermore, larvae showed a highly significant suppression of acetylcholinesterase activity upon exposure to both oils. Based on our results, the tested oils demonstrated potent insecticidal and repellent activities against the developmental stages of Galleria mellonella . These findings suggest their potential use as alternatives in integrated pest management (IPM) programs