Biotoxicity of Different Parts of Anacardium Occidentale (Linn.) against Callosobruchus Maculatus (F.) Infestation on Stored Cowpea Seeds

Biotoxicity of different parts of Anacardium occidentale extracted with different methods were tested against Callosobruchus maculatus infesting cowpea seed. The nut, stem bark, root bark and leaf of the plant were pulverized to fine powder. The extracts were made by soaking the powders in ethanol, hot and cold water and concentrations of 1, 2, 3 and 4% were made.  The mortality of the insect was observed at 24, 48, 72 and 96h post treatment. The oviposition and adult emergence of the beetle as well as the damage and weight loss of the seeds were recorded. All the extracts recorded high beetle mortality but only nut ethanolic extract achieved 100% mortality. Probit analysis showed that only little concentration of the extracts was required to achieve high mortality of the insect. The extracts significantly reduced the oviposition of the insect while the nut extracts of the plant prevented the emergence of the beetle and damage and weight loss of the seeds. Regression analysis showed that there was great correlation between adult mortality and oviposition as well as between adult emergence and weight loss. The extracts of the plant had proven insecticidal and can therefore be introduced to management system of the insect.