EFFECTS OF APPLICATION RATES OF SOME PLANT MATERIALS ON THE CONTROL OF RED FLOUR BEETLE, TRIBOLIUM CASTANEUM HERBST (COLEOPTERA: TENEBRIONIDAE) ON STORED MILLET (PENNISETUM GLAUCUM (L.) R. BR.)

Abstract

ABSTRACT Laboratory experiment was conducted to evaluate the effectiveness of leaf powders of six plants (Spider plant, Basil, Hyptis, Sugar apple, Desert date and Negro coffee) and a synthetic insecticide Pirimiphosmethyl (Actellic Dust) in controlling Tribolium castaneum Herbst in stored millet grain(Variety-Sosat). The leaf powders of each plant and the pirimiphos-methyl were tested at 2.5g, 5.0g and 7.5g/25g of sound millet grain. The experiment was laid in a completely randomized design and each treatment was replicated three times. Although both the plant product and synthetic treatments were significantly higher than control, Pirimiphos-methyl at all the tested concentrations caused significantly higher adult mortality of 3.17 at 22 hours after treatment (HAT) and 1.83 at 72 hours after treatment (HAT) than all the plant materials, with complete suppression of larval development and adult emergence at 15 and 45 days after treatment (DAT), respectively. Among the other treatment, desert date and sugar apple caused adult mortality of 1.00 and 1.29 at 22 and 72 HAT, respectively. This resulted into significant reduction in larval development, adult emergence and grain weight loss at 15, 45 and 63 DAT, respectively. Basil was next to sugar apple and desert date in terms of effectiveness, with grain weight loss of 1.98% and grain damage of 22.2%. Although, 5.0g and 7.5g concentration of plant powders were equally effective in reducing larval development and adult emergence, however, maximum grain protection was obtained with Sugar apple in 7.5g concentration/ 25g millet grain at 63 DAT, i.e. adult mortality was highest (1.29), while grain weight loss (2.82) and grain damage (10.6) were lowest at this concentration. Therefore, use of Sugar apple at the concentration of 7.5g/25g (i.e. 30% w/w) is recommended for the maximum protection of millet grain against damage by T. castaneum in storage.