TOXICITY OF ESSENTIAL OIL VAPORS TO STORED-PRODUCT INSECTS

Essential oils of the four plant species Pimpinella anisum L., Eucalyptus camaldulensis Dehn, Thymbra spicata L. var. spicata and Satureja thymbra L. achieved high toxicity (over 94% mortality) as vapour to at least two insect species tested with doses mostly in the range of 108-135 mul/l air and at exposure periods varying between 24-144 h. The essential oil of P. anisum caused a 95% mortality in Tribolium confusum du Val (adults), Sitophilus oryzae L. (adults) and Ephestia kuehniella Zeller (last instars), within shorter exposure periods than the other oils, 24 vs. 96 h in S. oryzae and 96 vs. 144 h in E. kuehniella. The essential oil of E. camaldulensis also caused high mortality in all insect species, in T. confusum only 86% within 168 h. Oils of T. spicata var. spicata and S. thymbra showed high toxicity only to S. oryzae and E. kuehniella.