This study assessed the reproduction inhibition effects of Adansonai digitata plant part powders against D. porcellus affecting yam chips. Reproduction of adults D. porcellus were monitored with various doses of Adansonai digitata plant part powders and untreated yam chips as negative control (0 g). The finding of the research indicated that all treatments exhibited anti-reproduction potential and strong inhibition of D. porcellus emergence. The result of analysis of variance showed significant difference between the treated samples and the control (untreated) after 37 days. Adansonai digitata stem bark powders (10 g) was able to achieve no reproduction(0.00) after 37 days exposure. Based on this results, combining yam chips with 10 g of Adansonai digitata stem bark powders could ensure adequate management of D. porcellus destroying yam chips and yam tubers as a whole. Keywords: Adansonai digitata, D. porcellus, yam chips, Stem bark powder, Leaf powder

This study evaluated insecticidal activity of different doses of Adansonia digitata stem bark and leaf powders on yam beetles dinoderus porcellus. Obtained plant parts from Federal colloge of Forestry, Jos were pulverized into powders. Phytochemical constituents of the plant were extracted by Soxhlet extraction and identified using standard procedure. Mortality testing was done by exposing dinoderus porcellus to yam chips mixed with various doses of Adansonia digitata stem bark and leaf powders. Yam chips without treatment served as the control. The experiments were laid out in randomized complete design with three replications. Data obtained were analysed using analysis of variance (P≤ 0.05). The result of the phytochemical examination of ethanolic extract of A. digitata revealed the presence of saponins, phenols, tannins and alkaloids flavonoids. The finding revealed the superiority of yam chips mixed stem bark and leaf powders over the untreated. The effect of plant extracts on percentage mortality showed significant difference (p<0.05) among the treated and control. The sample treated with 15g of A. digitata stem-bark powder gave the highest mortality. The research hence recommends the use of 15 g of A. digitata stem-bark powder in elimination of Dinoderus porcellus infecting yam chips. Keywords: A. digitata, Insecticida, Mortality, flavonoid, Dinoderus porcellus

The study aims at evaluating the efficacy of different doses of powdered stem and leaf parts of Gmelina arborea on Dinoderus porcellus infesting yam chips in Jos metropolis. The experiment was conducted at the Entomology Laboratory of the Federal College of Forestry, Jos. Samples of infested yam chips and Gmelina arborea were collected in Jos metropolis. Newly emerged adult Dinoderus porcellus were exposed to the yam chips which were mixed with different levels of Gmelina arborea parts powder (0, 5, 10, 15 and 20 g). The setup was monitored for 120 hours and mortality recorded. The study was carried out in a randomized complete design with treatments replicated thrice. Data was analysed using analysis of variance at 1 and 5 percent confidence level and Duncan test was used to separate the means. The results obtained reveal significant differences at p value=0.05 and 0.01. The results reveal that in all the doses, an increase in the amount of the powder resulted in increased incidence of D. porcellus mortality. After 120 hours of exposure, 100 % mortality was recorded from either 15 or 20 g stem bark + leaf powder treatment. From the results obtained, the use of 15 g stem bark+leaf powder of Gmelina arborea could be effective in yam chips preservation which could in turn strengthen food security. Keywords: Yam chips; Dioscorea spp; Stem bark; Botanical; Leaf powder