comparison between insecticide effects of wild and cultivated rosemary essential oils on stored product insects. s. khalil, k. zarrad, a. ben hammouda, y. ayed lakhal, s. rguez, w. tayeb, a. laarif, and i. chaieb. (tunisia)

This study was conducted to evaluate the insecticidal potential of Rosmarinus officinalis essential oils (wild and cultivated plants) against two stored product insects i.e. Tribolium castaneum and Trogoderma granarium. GC-MS analyses showed that both essential oils contain 4 major constituents which are L-camphor, 1,8-cinerole, L-borneol, and bornyl acetate. Fumigant toxicity tests showed that the two rosemary essential oils were more toxic to T. granarium than to T. castaneum adults. The corresponding LC50 values of wild and cultivated rosemary essential oils against T. castaneum were 65.5 μl/l air and 180 μl/l air, respectively, in contrast to 19.75 μl/l air and 18.75 μl/l air recorded towards T. granarium adults. Pest repellent activity was found to be dependent upon essential oil concentration and exposure time. The essential oil from wild rosemary plants was more repulsive against adults of T. castaneum than that from cultivated ones. Applied at the dose 0.25 µl/cm2 , repellency achieved was of about 65 and 45% after 120 min of exposure to essential oils from wild and cultivated rosemary, respectively. These results suggested that R. officinalis essential oils may be potentially active in controlling the two stored product insects.