The impact of Mesostena picca (Kraatz), a predator of the bruchid, Caryedon serratus (Olivier) on stored groundnut and tamarind was evaluated in the Laboratory of the Department of Crop Protection, Modibbo Adama University of Technology, Yola. Caryedon serratus (Olivier) is one of the major insect pests of groundnut and tamarind. Infestation results in characteristic round holes which causes qualitative and quantitative losses. Considering the limitations of conventional insecticides, there is a need for an alternative method of control. In this study, a non-chemical means of control for both consumption and sowing was sought. Groundnut and tamarind seeds were treated with the bio- agent, Mesotena picca Kraatz. The bruchid infestation was significantly reduced in the treated seeds compared to the control. The least number of eggs laid and the least mean percentage damaged seeds was obtained in chemical treated seeds in both stored products (67.00 and 64.33; 6.00 and 4.67) significantly followed by the bio-agent treated seeds (93.33 and 92.00; 32.00 and 31.00) and the highest was recorded in the untreated seeds (303.67 and 301.33; 90.00 and 85.33). The result also shows that, the highest mean percentage mortality, least mean percentage adults emerged and the least mean percentage weight loss in both stored products were observed in chemical treated seeds (97.23 and 95.33; 0.67 and 0.70; 3.67 and 3.33) significantly followed by the bio-agent treated seeds (86.27 and 86.17; 3.67 and 3.67) respectively. It was observed that, in the presence of the bio- agent, the bruchids could not freely feed on the stored products compared to the control. This reduces the extent of damage on the stored products.

Keyword:Evaluation, Loss, Bio-agent, Mesostena, Caryedon, Groundnut, Tamarind.

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