Bioactivities of different essential oils against the adults of two stored product insects

In this study we have tested fumigant toxicity often aromatic plant essential oils on red flour beetle,tribolium castaneum,and bean weevil,acanthoscelides obtectus,under laboratory conditions. the plant samples were collected from different sites of turkey,air dried at room temperature and the essential oils were obtained by steam distillation,using a clevenger-type apparatus. laurel and myrtle essential oils showed strong fumigant activity against a. obtectus and t. castaneum adults at different concentrations. estimated lc 50 and lc 99 values for a. obtectus adults were 45.31 and 70.75 μl/l air for myrtle,27.36 and 43.05 ul/l air for laurel or tansy oils,respectively. the t. casteneum were more resistant to myrtle and laurel than a. obtectus and lethality values were estimated as 92.80 (lc 50) and 159.03 (lc 99) μl/l air for myrtle 56.98 and 89.73 μl/l air for laurel oils,respectively. the mean longevity of a. obtectus adults was significantly decreased depending on the increasing doses of savory,myrtle,marjoram,laurel,lemon,tansy and sage essential oils. while savory,myrtle,marjoram and laurel essential oils decreased the mean longevity of t. castaneum adults the other essential oils did not change the longevity of these insects. copyright 2010 zoological society of pakistan.