If a farmer passes his grain bins one night and hears some rustling, it probably won’t be the headless horseman hanging around after Halloween.
But it could be another nightmare haunting farms well after its time is supposed to be past.
Entomologists and grain buyers say rusty grain beetles are running rank across the Prairies, thriving in warm fall temperatures that have given them many weeks more to chew through grain.
“It’s a big problem,” said Brandon Agpro elevator manager Vance Heubner. “There’s a lot of grain that needs to be cooled down.”
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Rusty grain beetles are always a problem with stored grain, especially after harvest.
But usually the bugs don’t get a chance to launch massive assaults because stored grain cools quickly below the temperature they need to breed and be active. Cold temperatures kill the bugs and their larvae.
Farmers who have problems generally auger their infected grain in and out of a bin on a cold night to break up the hot spots and cool the grain down.
But this fall it has been too warm for the grain to cool. Augering isn’t effective when outside temperatures aren’t well below zero.
Grain needs to fall below 18 C for the bugs to stop breeding, and below 15 C for the bugs to stop feeding.
Saskatchewan Wheat Pool Assiniboia elevator manager Vic Wall said a lot of cereals in his area are being brought to the elevator at 25 or 26 C, close to the temperature at which they were harvested.
He said it’s been a particularly bad problem with grain stored in huge bins.
“They just don’t cool down,” he said of bins with more than a 5,000 bushel capacity.
In his area, a lot of grain has been stored on the ground since harvest. A lot of it is being brought to the elevator with high rusty grain beetle larvae counts.
When that happens, farmers have to haul the grain home, treat it and then pay to truck it back to the elevator.
Canadian Grain Commission rules don’t allow any infestation.
Heubner said many local farmers are praying for cold weather so they can catch up to the beetles.
“It’s one of the worst falls I’ve ever seen,” he said. “It’s twice as bad as last year.”
Manitoba Agriculture entomologist John Gavloski said this year’s situation is particularly challenging because common control methods will be more difficult.
A chemical treatment called Phostoxin can be used, but new regulations mean farmers must have an applicator’s licence if they want to use it themselves. Otherwise, they must hire an exterminator. Both options cost time and money.
Agriculture Canada stored grain specialist Paul Fields said controlling reproduction is essential, because the rusty grain beetle can increase by 60 times in one month.
Gavloski said grain vacs tend to be more effective than augering, because the bugs are killed while being moved around.
If augering or using a grain vac, Gavloski suggested mixing in diatomaceous earth or powdered malathion.
Rusty grain beetles are hardy and can survive the cold if they cool slowly. Generally, they will die if the temperature drops to Ð5 C for six weeks. At -10 C it takes four weeks to kill them. At -15 C it takes two weeks.
Identifying the bug can also be a problem.
It looks similar to the foreign grain beetle that doesn’t eat stored grain but is often found in bins.
Fields said farmers can tell the difference by putting bugs in a glass jar. They aren’t rusty grain beetles if they can climb the sides.
For information on pests in stored grain, visit the Western Producer’s website at www.
producer.com.
