Evaluation of the Efficacy of Levo 2.4 Sl against the Cowpea Beetle, Callosobruchus maculatus (F.) on Stored Cowpea Grains

Abstract

The adverse effects of synthetic pesticides on the environment and non-target organisms have ne-cessitated the exploration of other safer and equally effective pesticides for the management of pests. The efficacy of Levo 2.4 SL (Oxymatrine 2.4 SL; Prosular oxamatrine a. i.), a botanical, against Callosobruchus maculatus (F.) infestation on stored cowpea, Vigna unguiculata (L.) (Walp.) was investigated in the insectary of the Entomology Section of the Faculty of Agriculture of the Kwame Nkrumah University of Science and Technology. The effects of Levo on the adult mortality, ovipoistion and F1 progeny of the insect were evaluated. Thus 200 g of cowpea grains were treated with three dosages; 0.01 ml, 0.02 ml and 0.03 ml of Levo 2.4 SL. Betallic Supper 2.5 EC (Primophos methyl and Permethrin a. i.) was used as a check and a Control (untreated grains) was also maintained. The mean number of eggs laid and the number of F1 adults that emerged were significantly (P < 0.05) smaller in the Levo treated grains than the control. The higher dos-ages of Levo 2.4 SL were more effective against C. maculatus infestation and damage. At the end of four months of storage, Levo at all the dosages offered complete protection to the cowpea grains. Levo 2.4 SL at a dosage of 0.02 ml is considered the right dosage that can give optimum protection to cowpea grains against C. maculatus.