Effect of The Sweet Orange Peel Extracts (Citrus Sinensis L.) On The Mortality Rate of Cowpea Weevils (CallosobruchusMaculatus. J.)

Abstract

The Insecticidal property of Citrus sinensis peel extracts was evaluated to determine their efficacy and optimize their use in reducing cowpea losses due to attack by Callosobruchusmaculatus. Varying concentrations of acetone, ethanol and methanol were obtained and evaluated at 6.25%, 12.5%, 25%, 50% and 100%. The mortality was monitored at 3days interval. The toxicity of the treatment was dependent on concentration and period ofexposure. Acetonic extract of Citrus sinensis was the most effective of all extracts. It caused 100% Callosobruchusmaculatus mortality at 100% concentration within 3 days of exposure. All rates of plant extracts caused mortality of bruchid and were significantly different compared with the control(P<0.05). There is a need to adapt the use of plant extracts in preventing damages against store pests. It is less toxic, environmental friendly, renewable, cheap and degradable. Protecting stored cowpea using Citrus sinensis peel at small- holder level is a viable storing method.