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Penetration of Sitophilus zeamais (Coleoptera: Curculionidae) through diatomaceous earth-treated bulk maize grain

  • B.M. Mvumi (a1), T.E. Stathers (a2), P. Golob (a2) and D.P. Giga (a3)

The penetration of adult Sitophilus zeamais Motschulsky through maize grain bulks (0.75 m deep), treated with Protect-It®, a diatomaceous earth (DE) at 0, 0.05, 0.1 and 0.2% (w/w), was determined 12 weeks after weevils were released at the upper surface of the grain. Maize was stored in columns in polyvinyl chloride (PVC) pipes, under controlled conditions of 26±2°C and 70±10% RH. Grain samples were collected from various pre-determined depths and the numbers of S. zeamais adults counted. Differences in insect numbers between treatments and at different depths from which samples were collected were highly significant (P<0.001). The bottom 2–3 layers (0.65–0.75 m deep) had significantly more insects than the upper layers for all the DE concentrations. No significant differences in total insect numbers (live+dead) were found between the DE concentrations. Dead S. zeamais weevils were found at the bottom of grain treated with Protect-It®, indicating that insects can penetrate through DE-treated grain 0.75 m deep but then subsequently die. There was no strong evidence that DEs admixed with bulk grain restrict S. zeamais movement within the grain.

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Z. Korunic (1998) Diatomaceous earths, a group of natural insecticides. Journal of Stored Products Research 34, 8797.

Z. Korunic , S. Cenkowski and P. G. Fields (1998) Grain bulk density as affected by diatomaceous earth and application method. Postharvest Biology and Technology 13, 8189.

Z. Korunic , P. G. Fields , M. I. P. Kovacs , J. S. Noll , O. M. Lukow , C. J. Demianyk and K. J. Shibley (1996) The effect of diatomaceous earth on grain quality. Postharvest Biology and Technology 9, 373387.

S. Navarro , T. G. Amos and P. Williams (1981) The effect of oxygen and carbon dioxide gradients on the vertical dispersion of grain insects in wheat. Journal of Stored Products Research 17, 101107.

M. Rigaux , E. Haubruge and P. G. Fields (2001) Mechanisms for tolerance to diatomaceous earth between strains of Tribolium castaneum. Entomologia Experimentalis et Applicata 101, 3339.

T. E. Stathers , B. M. Mvumi and P. Golob (2002) Field assessment of the efficacy and persistence of diatomaceous earths in protecting stored grain on small-scale farms in Zimbabwe. Crop Protection 21, 10331048.

G. Surtees (1964) Laboratory studies on dispersion behaviour of adult beetles in grain. VI. Three-dimensional analysis of dispersion of five species in a uniform bulk. Bulletin of Entomological Research 55, 723725.

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International Journal of Tropical Insect Science
  • ISSN: 1742-7584
  • EISSN: 1742-7592
  • URL: /core/journals/international-journal-of-tropical-insect-science
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