EFFECTIVENESS OF FOUR MEDICINAL PLANT ESSENTIAL OILS AS FEEDING DETERRENT TOWARDS DIFFERENT STRAINS OF STORED GRAIN INSECT PESTS

摘要

Stored products can be protected by applying essential oils as antifeeding agent. Essential oils extracted from Datura stramonium, Eucalyptus camaldulensis, Moringa oleifera and Nigella sativa were examined for feeding deterrent action against different strains of Tribolium castaneum, Trogoderma granarium and Cryptolestes ferrugineus. Test insects were allowed to feed on treated food with concentrations of 5, 10, 15 and 20% by keeping constant temperature of 30 +/- 2 degrees C and 65 +/- 5% relative humidity. Significant reduction in weight loss of treated food as compared with untreated was observed due to reduced feeding of insects. D. stramonium was the most active antifeedant with higher feeding deterrence index (FDI, 37.37%). Feeding deterrence index was found to increase from 22.01 to 43.70% with the increase in concentrations of essential oils from 5 to 20%. Among strains, FDI (%) of essential oils was recorded highest against SWL (Sahiwal) strain of T. castaneum and T. granarium while no significant difference was observed among strains of C. ferrugineus. Essential oils possessed antifeeding/deterrent properties and must be used as grain protectants in future.