Harvesting and Storing
Wheat--Good News, and Bad
By Linda McGraw
October 11, 2000
Newly harvested wheat is generally
not infested with insects, an Agricultural
Research Service scientist reports. Now for the bad news: Insects immigrate
into grain bins within 30 days after harvest. Thats the word from
Manhattan, Kan., where the researcher is counting insects immigrating into
grain bins from the outside.
Entomologist David W. Hagstrum used traps to monitor 34 grain bins on 12
different Kansas farms. The traps allowed him to check the numbers of insects
entering through openings between the roof and bin cap and under the eves,
between the roof and the bin wall. Bin sizes ranged from 1,000 to 8,000
bushels. On a average, 14 rusty grain beetles, six lesser grain borers, six
foreign grain beetles, and 22 hairy fungus beetles immigrated into these bins
each day during the first month of storage.
Hagstrum and ARS entomologist Paul W. Flinn will use this information to
strengthen the accuracy of Stored Grain Advisor (SGA), a personal computer
model developed to help grain managers select the best timing for control
methods. Such guidance can help reduce the cost of insect pest management. A
special form of SGA developed for use in large grain elevators--SGA Pro--is
being released in beta version for use by grain elevators in the
Kansas-Oklahoma area-wide IPM project this fall. The public can obtain a copy
of SPA Pro from Flinn in the spring of 2001.
Each year, more than 2 billion bushels of wheat are produced in the United
States, with most of it stored in a grain elevator at some point. Some is
stored before milling. Much stored grain is awaiting export to other countries.
In either case, stored grain insect pests such as the lesser grain borer, rice
weevil, red flour beetle and rusty grain beetle cost the U.S. wheat industry
about $500 million annually.
ARS is the chief scientific research agency of the
U.S. Department of Agriculture.
Scientific contact: David Hagstrum, ARS
Grain Marketing and Production Research
Center, Manhattan, Kan., phone (785) 776-2718, fax (785) 776-0962,