Toxicity and repellency of nine medicinal plants against Tribolium castaneum in stored wheat

Abstract

Aqueous and methanolic plant extracts of Ambrosia tenuifolia Spreng., Baccharis trimera (Less.) DC, Brassica campestris L., Jacaranda mimosifolia D. Don, Matricaria chamomilla L., Schinus molle (L.) var. areira (L.) DC., Solanum sisymbriifolium Lam., Tagetes minuta L. and Viola arvensis Murray were tested in the laboratory for their insecticidal and repellent effectiveness against the red flour beetle, Tribolium castaneum (Herbst) (Coleoptera Tenebrionidae). The adult beetles were exposed to plant extracts by topical application and grain treatment. Mortality was recorded after 1, 2 and 7 days after exposure. The repellent action of these plant extracts was also studied. Only methanolic extracts showed activity. The highest mortality (68%) of T. castaneum was caused by V. arvensis on grain, followed by M. chamomilla (57%), B. campestris (56%) and J. mimosifolia (49%) after 7 days. Moreover, J. mimosifolia, M. chamomilla and T. minuta exhibited high repellency (IR = 0.04) against insects. The application of these botanicals may be promising in protecting of stored grains against coleopteran pests.