Effects of Juglone on the Antioxidant Metabolism in the Larval Hemolymph of the Greater Wax Moth Galleria mellonella L. (Lepidoptera: Pyralidae)

Reducing the usage of chemical pesticides used to control pests in agriculture and stored products is an important phenomenon. Also, eco-friendly biopesticides have become highly important for use in the management of the pest control programs to overcome the negative influences of other synthetic chemicals. In this study oxidative stress changes induced by one important phytochemical compound, juglone, in Galleria mellonella larvae were investigated. For this purpose, effective concentrations (LC10: 0.5 mg; LC30: 1.5 mg; LC50: 2.3 mg) of juglone were added into the 2 g diet of the first instar larvae. Hemolymph samples from the last instar larvae were used to analyses of antioxidant enzyme activity (glutathione peroxidases – GPx, glutathione-S transferase - GST, catalase - CAT, and superoxide dismutase - SOD) and malondialdehyde (MDA) assays. Activities of antioxidant enzymes (SOD, CAT, and GST) and MDA level in the hemolymph of last instar G. mellonella larvae exposed to dietary juglone changed dose-dependently when compared to the control larvae. However, there was no change detected in GPx enzyme activity in both treated and untreated larvae. Consequently, effective doses of juglone are toxic to the model and pest insect G. mellonella.