Biological activities of Hypericum perforatum L. Essential oil against red flour beetle, Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae)

Abstract

Background: Exploration of eco-friendly pesticides is necessary because of the side effects of synthetic chemicals such as environmental hazards, pest resistance and toxic effects on non-target organisms. Many plant essential oils have indicated potential insecticidal effects against several insect pests. Materials and Methods: The essential oil of Hypericum perforatum L (Hypericaceae) was obtained by steam distillation and its chemical composition along with fumigant toxicity and antifeedant activity were evaluated against the adults of red flour beetle, Tribolium castaneum (Herbst). Results: Fourteen components were identified in the essential oil that characterized by the following main constituents: Decane (59.58%), dodecane (12.93%), ethylcydohexane (6.84%), 5-methylnonane (4.71%), 3-methylnonane (432%) and tetradecane (3.82%). Results of fumigant toxicity showed H. perforatum essential oil has remarkable biological activity which depended on essential oil concentrations and exposure times. As the exposure time increased the mortality rate increased and the LC50 values decreased from 15.048 μL L-1 air at 24 h to 11.743 μL L-1 air at 72 h exposure time. About 24 h sub-lethal concentrations (LC25-LC45μL L-1 air) were used in antifeedant bioassays. Essential oil of H. perforatum had significant antifeedant effects on T. castaneum. The LC45 (14.13 μL L-1 air) caused highest Feeding Deterrence Index (FDI) of 95.78%. Conclusion: Results of present study revealed that essential oil of H. perforatum have potential Insecticidal effects on T. castaneum and this essential oil can be a natural alternative to harmful chemical insecticides in the integrated management of T. castaneum.