Toxicity of crude extracts of Nigerian spices to post flowering insect pests of cowpea [Vigna unguiculata(L.) Walp]. 1. The legume flower bud thrips,Megalurothrips sjostedtiTrybom

Abstract The efficacy of crude aqueous extracts of Piper guineense Thonn & Schum, Aframomum melegueta Schum, Xylopia aethiopica (Dunal) A. Richard, Zingiber officinarum L. and Capsicum annum L. was evaluated for the control of legume flower bud thrips on cowpea. These extracts were applied at 10% and sprayed once weekly for four weeks during 1997, 1998 and 1999 cropping seasons. The extracts reduced the population of thrips and gave significant (p < 0.05) protection to cowpea flowers compared to the untreated control during the three years cropping seasons. Pod production was significantly higher (p < 0.01) on plots treated with P. guineense, followed by A. melegueta extracts. This study highlights the potentials of crude aqueous extracts of P. guineense and A. melegueta as biopesticides for thrips control on cowpea flowers. This technology is safe, easy to adopt, environmentally friendly and cheap.