Location: Stored Product Insect Research Unit
Title: Seasonal Distribution of Psocids in Stored Wheat Authors
Submitted to: Meeting Abstract
Publication Type: Other
Publication Acceptance Date: June 6, 2006
Publication Date: October 15, 2006
Citation: Throne, J.E., Opit, G.P., Flinn, P.W. 2006. Seasonal distribution of psocids in stored wheat. Meeting Abstract. 9th International Working Conference on Stored Product Protection, Campinas, Brazil, 15-18 October, 2006. Technical Abstract: Psocids are an emerging problem in grain stored in the U.S. and in grain processing facilities. We conducted preliminary studies to determine which species of psocids were present in a feed mill, a grain elevator, and in wheat stored in steel bins. We then conducted a more extensive study in steel bins containing wheat to determine temporal and spatial distribution of psocids in the wheat. We also compared several sampling methods for the psocids – cardboard refuges, grain trier samples, and automated sampling using the StorMax Insector system. The predominant psocid species found in all locations was Liposcelis entomophila. In the study on temperospatial distribution, infestation levels before the bins were filled with wheat were low, but some psocids were present in the empty bins. Numbers of psocids caught on sticky traps on the outside of bins dropped quickly as ambient temperatures dropped. Number of psocids in cardboard refuges on the wheat surface were low immediately after bins were filled in July, peaked in October, dropped to almost zero in December as temperatures dropped during winter, and then remained at low levels until the study was ended in April. Number of psocids in cardboard refuges within bins did not vary with location on the surface of the grain. Number of psocids in cardboard refuges was indicative of number of psocids in grain samples. The results indicate that cardboard refuges may provide an efficient method for sampling psocids in bins of wheat, and that psocid populations can increase quickly to high levels during storage even though they are low early in the storage period.