Hermetic storage of wheat and maize flour protects against red flour beetle (Tribolium castaneum Herbst).

Yan Yan,Scott B Williams,Dieudonne Baributsa,Larry L Murdock,Richard Mankin

doi:10.1371/journal.pone.0185386

Yan Yan, Scott B Williams + Show 3 more

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https://doi.org/10.1371/journal.pone.0185386

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Abstract

Hermetic storage is used to protect grain against insect pests, but its utility is not limited to whole grains. We evaluated hermetically-sealed, polyethylene terephthalate (PET) bottles for preserving wheat and maize flour against red flour beetle (RFB, Tribolium castaneum, Herbst) population growth. Flours infested with RFB and kept in sealed PET bottles experienced much less weight loss over a three-month storage period than infested flour kept in unsealed bottles. RFB populations in wheat flour kept in sealed bottles did not increase, while populations in unsealed bottles grew about 50-fold during the same three-month period. Flour in sealed bottles had lower levels of oxygen and moisture than flour stored in unsealed bottles. Similar trends were observed for oxygen and moisture levels in maize flour held in hermetically sealed bottles. Hermetically-sealed bottles were effective in preventing RFB population growth and preserving maize and wheat flour. Farmers, consumers and food processors can safely store grain flour in hermetic sealed containers.

Highlights

Red flour beetle (RFB), Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae), is a major economic pest of flour and other processed food products [1,2,3]
Hermetic sealing had a significant effect on internal oxygen levels in the bottles (wheat flour: F(3, 32) = 454.5, P < 0.0001; maize flour: F(3, 32) = 374.3, P < 0.0001) (Fig 1)
In the unsealed bottles containing wheat flour with insects present, the oxygen levels slowly decreased to 17% (v/v) during the first month, and dropped more rapidly to between 8–10% (v/v) by the 50 day mark (Fig 1a)

Summary

Introduction

Red flour beetle (RFB), Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae), is a major economic pest of flour and other processed food products [1,2,3]. Poor storage and handling practices by smallholder farmers make it easier for insects to infest stored grain [4]. Insect infestations cause a reduction in grain weight, lower nutritional and economic value, and reduced seed germination. Fumigants have been routinely used to control insect populations in stored products. The major fumigants used worldwide have been phosphine and methyl bromide. These chemical control methods are becoming less effective due to the development of resistance and are subject to environmental concerns. New management alternatives are needed [8,9,10,11,12,13]

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