Pesticide Potential of Gmelina arborea Stem Bark and Leaf Powder against Infesting Yam Chips

Abstract

Insect pest are a major problem to food security, most especially in developing countries like Nigeria. There is an urgent need towards mitigating the effects of these group of insects, and botanical extracts had played an increasing role as an alternative insecticide. The aim of the present study is to investigate the anti-feeding effect of different dosage of Gmelina arborea stem bark and leaf powder against Dinoderus porcellus infesting yam chips. The study was conducted at the Entomology Laboratory of Federal College of Forestry, Jos. Soxhlet extraction using methanol was used to extract plant part samples. Presence of phytochemicals contained in the plant were examined following standard protocols. The antifeedant effects of different dosage of Gmelina arborea leaf and stem bark powder on Dinoderus porcellus was determined by monitoring yam chips weight loss. Data collected was subjected to analysis of variance (ANOVA) at 1 % level of significance and the means separated using Duncan test. The results revealed presence of tannin, flavoid, saponins, alkaloids, reducing sugar and phenol with absence of steroid. The results also revealed that the various dosages have remarkable antifeedant effect on the development of D. porcellus. The weight loss of treated yam chips was significantly different from those of untreated yam chips. Therefore, the results obtained in this work accounts for the use of G. arborea plant parts powders as bio-preservative for yam chips against D. porcellus.