EFFECT OF EXTRACTION SOLVENTS ON THE EFFICACY OF Azadirachta indica A. Juss؛" Cannabis sativa L. AND Citrullus colocynthis Schrad SEED EXTRACTS IN REDUCING OVIPOSTON, EGG-HATCH AND ADULT EMERGENCE IN Callosobruchus maculatus (F.)

Extracts obtained from the seeds of Azadirachta indica, Cannabis sativa and Citrullus colocynthis, using acetone, methanol, ethanol and water as solvents, were assessed for their efficacy in reducing oviposition, egg-hatch and adult emergence in Callosobruchus maculatus (F.). The extracts were applied to cowpea seeds either before or after seed exposure to gravid female bruchids for oviposition. Relative to extract-free control, extracts obtained with acetone, methanol, ethanol and water reduced oviposition on average, by 70.9, 65.0, 79.9 and 21.690, egg-hatch by 77.2, 50.8, 54.5 and 23.7% and adult emergence by 99.9, 68.1, 76.3 and 53.716 respectively. Organic solvent extracts, especially those obtained with acetone, caused significantly higher reductions in oviposition, egg-hatch and adult emergence than water extracts. For each plant seed, the extracts obtained with water performed better on previously uninfested than on already infested cowpea seeds in reducing bruchid populations.