Seasonal patterns of stored-product insect activity in head spaces of grain bins

Stored product insect and their dispersal throughout the headspaces of grain bins were correlated with seasonal patterns of temperature. Migration of pests into wheat and rice bins was studied at two locations. Effects of pressure and suction aeration was also investigated. Temperature monitoring was done using Hobo® Data Loggers and insect activity was monitored using 5 38.1 cm x 30.5 cm x 4.3 cm wood frame square screen traps coated with Tangle-Trap® that were placed in the north, east, south, west and center quadrants on the grain surface for the purpose of monitoring insect movement in and out of the grain for a period of 5 months in Beaumont, Texas in rice and 8 months in Manhattan, Kansas in wheat. Temperature was highly correlated with insect activity within grain silos and even more so in pressure aeration due to air being pushed up through warmer grain and into the bin headspace. Other methods of dispersal were also investigated. Rhyzopertha dominica climbing ability inside the grain silo headspace on soiled surfaces was confirmed, but needs more investigation. A laboratory study using Rhyzopertha dominica in differing grain and headspace temperatures, and how these correlate with flight activity, is also being investigated.