Efficacy of Candlewood <i>Zanthoxylum xanthoxyloides</i> (Lam.) for the control of <i>Sitophilus zeamais</i> (Mots.) (Coleoptera: Curculionidae) and <i>Callosobruchus maculatus</i> F. (Coleoptera: Bruchidae)

Abstract

The bioactivity of dried leaves, bark and root of Zanthoxylum xanthoxyloides (Lam.) was assessed in the laboratory for their ability to protect stored grains from damage by Sitophilus zeamais and Callosobruchus maculatus on maize and cowpea, respectively. One hundred grams of sterilized grains were measured in glass jars and the ground plant materials added as direct admixtures to test for toxicity, progeny production and weight loss. The plant materials tested initially at a concentration of 5% (wt/wt) showed the root and bark inducing 100% mortality and causing significant (P<0.001) reduction in damage and progeny emergence. Further test with dried root and bark at various concentrations demonstrated that 0.5% (wt/wt) gave complete protection of grains against beetle infestation with no observable damage to grains. The potential practical use of Z. xanthoxyloides as grain protectant in farm-stored grains is discussed.

KEY WORDS: Zanthoxylum, Efficacy, Sitophilus, Callosobruchus, stored grains.

Global Journal of Agricultural Sciences Vol.3(1&2) 2004: 19-23