Development of Granary Weevils and Fungi in Columns of Wheat1

Abstract

Wheat at 11 to 12% moisture content was stored in cylinders 6 inches in diameter and 36 inches tall, was inoculated with weevils, and samples removed at intervals and tested for moisture content, storage fungi, and number of weevils. When the weevils were introduced at the bottom of the column and were not confined, they gradually moved to the top. In the portion of grain where they increased, moisture content and storage fungi also increased. When the weevils were confined in grain of 15% moisture in dacron doth bags at the bottom of the columns, and the columns filled with grain at 11 to 12% moisture content, moisture content and storage fungi increased greatly in the grain where the insects were confined, increased appreciably in the grain 6 inches above, and slightly in the grain 12 inches above the portion where the insects were confined. It seems probable, therefore, that under conditions that prevail in bulk stored grain, a localized infestation by weevils may initiate and promote deterioration by storage fungi in a volume of grain considerably larger than that in which the insects are developing.