Comparative Performance of Prostephanus Truncatus(Horn) (Coleoptera:bostrichidae) on Different Processed Varieties of Cassava (Manihot Esculenta(Crantz)) Chips Treated With Zingiber Officinale and Deltamethin

Abstract

In Africa, Prostephanus truncatus is a destructive pest of economic importance which has deteriorative effects on dry cassava chips in storage. The present study investigates the effects of Zingiber officinale on P.truncatus on dried cassava chips processed in two methods. Deltamethrin was used as the reference insecticide. The plant extract was used at different concentrations (500ul/ml, 250ul/ml, 125ul/ml, 62.5ul/ml, 0ul/ml(control) and 0.05ul/ml(reference)). The cassava varieties used are TME 419 and TMS 98/0581. the cassava varieties were cut into cubes and subjected to two processing methods, parboiling and unparboiling (plain). Percentage emergence was assesed as thus, 100g of cassava chips were put in a plastic plate. 10 unsexed adult of P.truncatus were introduced into each plate and left for 14days to oviposit, after which the insects were removed , the chips were thereafter treated with Z.officinale at (500ul/ml, 250ul/ml, 125ul/ml, 62.5ul/ml, 0ul/ml(control) and 0.05ul/l(Deltamethrin). The plates were covered with muslin cloth held with a rubber band and left to stand for 25 days. Afterwhich the percentage emergence was assessed, by counting. All the data generated were subjected to one-way analysis of variance (ANOVA) in Genstat package 9.2 (9th edition). Difference between mean values were separated using least significant difference (LSD) at P<0.05 (Finney 1971). The result of the experiment showed that Z.officinale conferred greater protection to the chips at higher concentrations of 250ul/ml and 500ul/ml , its effects were similar to the reference insecticide. Processing methods recorded a great significance(P <0.05) .

Effect of Hexane and Methanol Extracts of Piper guineense (Schum and Thonn) Seeds against the Maize Weevil (Sitophilus zeamais) in Stored Maize Grains

“…Control treatment with plane acetone was included. Subsequently, ten unsexed adults of S. zeamais were introduced into each of the petri dishes already treated with the hexane and methanolic extracts respectively (Ejiofor and Okonkwo, 2023). Daily mortality counts were taken for seven days.…”