Insecticidal Efficacy of Raw Diatomaceous Earth, and Jatropha curcas Seed Powder Alone, and in Combination against Callosobruchus subinnotatus (Pic) [Coleptera: Chrysomelidae) in Stored Bambara Nut (Vigna subterranea L. Verdc.) Seeds


  1. Department of Agricultural Technology, Ramat Polytechnic, Maiduguri, Nigeria.
  2. 2.Department of Biochemistry, Usmanu Danfodiyo University, Sokoto, Nigeria

Nig. J. Entomol. 33: 73-82 (2017)

DOI: 10.36108/NJE/7102/33(0190)

ABSTRACT: Laboratory bioassay were conducted to assess the insecticidal efficacy of raw diatomaceous earth (ROE), Jatropha curcas seed powders (.ISP) alone and in combination against Callosobruchus subinnotatus in stored bambara nut seeds. The study was carried out under ambient laboratory conditions at 30 ± 2 “C and 55 ± 4 % relative humidity using Completely Randomized Design. The seeds were admixed with the RDE, JSP each at tbree dose rates as unitary (RDE: 0.5, 1.0 and 1.5 g/100 g) and (JSP: 0.5, 1.0 and 2.0 gll 00 g) and their binary combination at (0.5+0.5, 1.0+ 1.0, 1.5+2.0 g/100g).Actellic dust at the rate of 2.0 g/kg and untreated control were used as positive and negative controls, respectively. Each glass jar (500 ml) was later infested with 30, 1-2-days old C.
of mixed sexes. Adult mortality was assessed from 24 hours to 96 hours after treatment
(HAT). F1, F2 adult emergence at 32 and 74 days after treatment (OAT) and percentage seed damage and
weight loss were assessed after 90 days. The germination of bambara nut seeds were evaluated at the beginning (before infestation) and after 90 days of treatments and infestation. The results revealed that
binary combination of test powders were most effective than either RDE or JSP as unitary applications.
The highest dose rates 0 [the binary combination resulted in 100% adult mortality at 72 HAT. Similarly,
all treatments demonstrated reduced mean number of F1, F2 adult emergence, seed damage and weight
loss compared to the untreated control. Significantly, higher germination percentage was recorded in
all treatments before infestation. However, after 90 days of treatments and infestation, the germination
capacity of treated seeds decreased, which was significantly different from the untreated control.
Bambara nut seeds treated with binary combination gave the best protection against C. subinnotatus and thus can be incorporated into integrated stored pest management.
Keywords: Raw diatomaceous earth, Jatropha curcas seeds, Callosobruchus subinnotatus. Unitary, Binarv combination.

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