Efficacy of some indigenous plant powders against Callosobruchus chinensis (L.) infesting rice bean

The plant powders viz., rhizome of Costus speciosus, leaf of Diospyros lanceafolia Roxb., seed coat of Diospyros lanceafolia, leaf of Juglans regia, seed of Litsea citrata leaf of Ocimum sanctum, seed of Piper nigrum, leaf of Zanthoxylum oxyphyllum Edgw. and seed coat of Zanthoxylum oxyphyllum @ 5% w/w were evaluated as grain protectants against Callosobruchus chinensis (L.) on rice bean seeds. Based on the parameters like oviposition, adult emergence, seed infestation and weight loss, L. citrata was observed the most effective up to 2 months of storage. It was closely followed by P. nigrum, D. lanceafolia and J. regia, while Z. oxyphyllum and C. speciosus were the least effective. These powders had no adverse effect on seed germinability. L. citrata and P. nigrum could reduce egg laying and adult emergence by 63.14 to 66.16% and 50.49 to 59.50%, respectively.