THE CHEMICAL COMPOSITION OF CYCLOTRICHIUM ORIGANIFOLIUM ESSENTIAL OIL AND ITS INSECTICIDAL ACTIVITY AGAINST FOUR STORED-PRODUCT INSECT PESTS

Stored-product insect pests, Acanthoscelides obtectus, Tribolium castaneum, Ephestia kuehniella and Plodia interpunctella cause serious problems all over the world and cause significant losses in agricultural crops every year. In the present study, the essential oil from Cyclotrichium origanifolium (La bill.) Manden. & Scheng. (Labiatae) was extracted, chemically characterized and tested on these insect pests. Essential oil yield was estimated to be 0.95% (v/w) with major components being pulegone (74.60%) and menthone (16.61%). Limonene (1.12%) and isopulegone (1.09%) followed the major components. Significant insecticidal activity was achieved by treating the insect pests with the essential oil. Complete mortality was obtained on A. obtectus and T. castaneum adults at the 40 mu l L-1 air concentration during 24 h exposure period. More pronounced effect was observed on the adults of E. kuehniella and P. interpunctella. Nearly complete mortality was obtained at the 8 mu l L-1 air concentration. The results indicated that C. origanifolium essential oil displayed promising effects in controlling stored-product insect pests