Evaluation of the Insecticidal and Biochemical Impacts of Linseed Oil, KZ Oil, and Oleic Acid on Galleria mellonella, Larvae

Galleria mellonella (Lepidoptera: Pyralidae), is one of the graver pests affecting honeybee colonies, causing severe damage to stored wax combs and weakening hive productivity. The present study aimed to evaluate the insecticidal, biological, and biochemical impacts of three natural compounds, KZ oil, linseed oil, and oleic acid, on 6th instar larvae of G. mellonella under laboratory conditions. Results disclosed that linseed oil showed the highest mortality rates, based on LC50 with (8.00) µg/ml, followed by KZ oil (10.80) µg/ml, while oleic acid exhibited relatively lower toxicity with (13.02) µg/ml. Beyond direct seriousness, the tested compounds influenced several biological aspects, involving larval duration, pupation %, and adult emergence. According to the findings, all tested materials at different concentrations (2, 4, 8 and 16%) resulted in prolongation of larval and pupal duration, while caused a reduction in pupation % and adult emergence compared to the control. Notably, KZ oil at higher concentration (16%) induced a high incidence of morphological deformations in both pupae and emerged adults, further impairing successful development, whereas linseed oil produced only limited alterations. GC is a powerful analytical tool used to identify fatty acid components of linseed oil and oleic acid. In addition, all examined materials at LC25 and after one week, elevated the activity of chitinase enzyme and decreased that of acid phosphatase (ACP), also showing comparatively mild effects on protein content. These results highlight the potential of KZ oil, linseed oil, and oleic acid as an effective, eco-friendly alternative for greater wax moth management.