Efficacy of Plant Oils as Grain Protectants against Khapra Beetle, Trogoderma Granarium Everts in Wheat

Laboratory experiments were conducted during 2003–04 and 2004–05 with wheat, Triticum aestivum L. to determine the efficacy of biopesticide (plant oils) as grain protectants against khapra beetle, Trogoderma granarium Everts. The duration of combined larval and pupal stages varied from 27.03 to 39.22 days, being maximum in neem oil (39.22 days) and minimum in sunflower oil (27.03 days). The adult emergence was lowest (23.77%) in neem oil treatment and highest in sunflower oil (43.99%). The number of eggs laid per female at different dose levels ranged from 28.18 to 38.52, the neem oil was the most effective in reducing the fecundity (24.44 eggs/female) and the least effective was sunflower oil (43.33 eggs/female). The grain damage ranged from 9.36 to 25.16% and, the most effective treatment was neem oil (9.36%). The weight loss at different dose levels ranged from 3.51 to 8.27% and this gradually decreased with the increase in dose.