Page Banner

United States Department of Agriculture

Agricultural Research Service

Research Project: ECOLOGY, SAMPLING, AND MODELING OF INSECT PESTS OF STORED GRAIN, PROCESSING FACILITIES, AND WAREHOUSES

Location: Stored Product Insect Research Unit

Title: Temperospatial distribution of the psocids Liposcelis entomophila and L. decolor in steel bins containing wheat

Authors
item Opit, George
item Throne, James
item Flinn, Paul

Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 2, 2009
Publication Date: June 1, 2009
Citation: Opit, G.P., Throne, J.E., Flinn, P.W. 2009. Temporospatial Distribution of the Psocids Liposcelis entomophila and L. decolor in Steel Bins Containing Wheat. Journal of Economic Entomology 102: 1369-1376.

Interpretive Summary: Psocids are an emerging problem in stored grain and in grain processing facilities in the U.S. We investigated seasonal distribution of psocids in wheat stored in steel bins and compared several methods for sampling psocids in the wheat – cardboard refuges on the surface of the grain and on the underside of the bin hatch, grain samples, and automated sampling using the StorMax Insector™ system. Two species of psocids were found - Liposcelis entomophila in 2005 and L. decolor in 2006. Numbers of psocids in cardboard refuges on the wheat surface were low immediately after bins were filled in July 2005, peaked in October, dropped to almost zero in December, and then remained at low levels until the study was ended in April. The results indicate that cardboard refuges or Insectors™ may provide an efficient method for sampling psocids in bins of wheat, and the results could be used to time pest management during the peak infestation period.

Technical Abstract: We investigated the temperospatial distribution of psocids in steel bins containing 32.6 metric tonnes of wheat. Psocids were sampled using a grain trier, cardboard refuges on the surface of the grain and near the bin hatch, and automated sampling using the StorMax Insector™ system. The psocid species found were Liposcelis entomophila in 2005 and L. decolor in 2006. Generally, seasonal abundance was similar using the different sampling methods. Numbers of psocids in cardboard refuges on the wheat surface were low immediately after bins were filled in July 2005, peaked in October, dropped to almost zero in December as temperatures decreased during winter, and then remained at low levels until the study was ended in April. In 2006, the number of psocids in surface refuges increased gradually from August to mid-October, and then declined until the study was ended in early November. Numbers of psocids in cardboard refuges and in Insector™ probes were indicative of numbers of psocids in grain samples in both years. Psocids were more abundant at the center of the bin in the fall than around the periphery. At the center of the bin, psocids were more abundant at depths of 0.85-1.96 m than depths of 0-0.84 m. The results indicate that cardboard refuges or Insectors™ 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.

Last Modified: 7/28/2014
Footer Content Back to Top of Page