GROWTH INHIBITION AND TOXIC EFFECT OF BAKAIN SEED AQUEOUS EXTRACT ON PULSE BEETLE, Callosobruchus chinensis L. (COLEOPTERA: BRUCHIDAE).

Abstract

Laboratory experiments were conducted in Entomology Department, Faculty of Agriculture, Gomal University, D.I. Khan, Pakistan to investigate growth inhibition and toxic effect of bakain (Melia azedarach L.) seed aqueous extract on pulse beetle (Callosobruchus chinensis L.) infesting chickpea (Cicer arietinum L.) during storage. Different concentrations of bakain seed extract, viz. 0.4, 0.3, 0.2, 0.1, 0.05 and 0.025% (v/w) were evaluated. The results showed that bakain seed extract significantly reduced oviposition and suppressed adult emergence of pulse beetle. Consequently, it reduced damage and weight loss of chickpea grains. The effectiveness of bakain seed extract was found to be dose dependent. It exhibited maximum growth inhibition activity at the concentration of 0.4 and 0.3%. The treatments had no significant effect on adult life span of pulse beetle. Aqueous extract of bakain seed also showed some degree of toxicity against the pest. It caused maximum mortality of the pest at the concentration of 0.4 and 0.3% after 72 hours of release in treated chickpea grains. On the basis of these results, it was concluded that bakain seed aqueous extract could be effectively used for the management of pulse beetle during storage.