Grain properties and insect distribution trends in silos of wheat

In the current work, we correlate previously reported data for stored-product beetle populations in three silos from Central Greece, with the respective grain moisture content, temperature and bulk density. The insect numbers were obtained by the use of grain trier samples, and grouped in three zones, the central zone, the median zone and the edge zone, corresponding to the areas close to the center of the bulk, the intermediate area and the peripheral area, close to the walls. On each sampling date and location, there were measurements of moisture content, temperature and bulk density. In general, despite variations among silos, the central zone was warmer, drier and had lower bulk density levels than the other zones. Moreover, the previously reported data for beetle populations indicated that more insects were found in the central zone. Moisture content, temperature and bulk density were well correlated, but none of these parameters were correlated well with insect numbers. The results of the present work suggest that there are simultaneous and associated changes with these three parameters during the storage period, but these changes cannot be used accurately as predictors of insect infestation patterns and distribution. Hence, using these factors as insect density predictors is a complex phenomenon with multiple interactions with stored product insect biological and behavioral parameters. (c) 2020 Elsevier Ltd. All rights reserved.