Seasonal changes in mite (Acari) and fungal populations in aerated and unaerated wheat stored for three years

Abstract

In experiments at Slough, southern England, one hundred tonnes of wheat at about 14% moisture content were divided between six similar metal bins, three of which were aerated during the winter. Observations were made on the mite and fungal populations and physical conditions for an uninterrupted storage period of three years. During the winter, the wheat in the aerated bins was 2–4°C cooler than that in the unaerated bins and it always had a moisture content 0·5–1% higher, except at the surface where it was usually drier. Aeration appeared to delay the increase of Acarus siro L. and Lepidoglyphus destructor (Schr.) for 4–6 months after harvest, but few individuals survived into the second year of storage in any bin. Cheyletus eruditus (Schr.) and Tydeus interruptus Thor were present after one year and were most numerous in the aerated bins. The distribution within the bins of the different species of mites varied with season. A greater increase in storage fungi occurred in the aerated bins than the unaerated. Members of the Aspergillus glaucus and A. restrictus groups, Penicillium spp. and Wallemia sebi were the commonest fungi.