Canada: Warm December delighted grain beetles; farmers not so much

Unusually warm weather that lasted into early January prompted a Saskatchewan farmer to warn producers about hot spots and insects in grain bins.

“I’m hearing that more and more farmers are finding bugs,” said Michael Reimer, who primarily grows durum wheat near Eston, Sask. “I mean, a year ago, we were at minus 30 C and that would take care of a lot of the problem, but you get plus 12 C and plus 11 and 10 C in around Christmas, that’s not normal.”

The Weather Network said last month was the warmest December on record in many locations, from British Columbia to northwestern Ontario, partly due to a strong El Nino.

An expected polar vortex will likely cause a temperature plunge across the Prairies in January, affecting insects in grain bins, said Brent Elliott, program manager for infestation control and sanitation at the Canadian Grain Commission.

“I hope every aeration fan and every bin across the Prairies is open in the next week or two,” he said in an interview Jan. 5. “And of course, it’s not everyone, but you hope every bin has temperature probes in it and guys are monitoring it and keeping the temperature low because that’s a real good indicator that you may have insect problems, too, if your grain has got hot spots.”

Reimer said rusty grain beetles were recently found in a 4,500-bushel bin on his farm. He has about 30 bins ranging up to 30,000 bushels each.

“I haven’t any trouble with the big bins, but with them, by the time you find you’ve got a problem, it could be too late.”

He noticed a smaller bin lacked a frost line, leading him to suspect insects.

“We took a Super-B load out and I hauled it to town, and yep, they found bugs in it.”

Reimer used phostoxin, a chemical fumigant, to kill the rusty grain beetles, which were caught early enough that they didn’t affect the grade.

“At the elevator, they said they’re hearing of farmers finding them, so I’ve been telling guys in town. I said, ‘check your bins because it’s been too warm’.”

Elliott said the warning is timely.

“We’ve heard a number of reports out of Alberta as well, and I think it’s related as much during the El Nino year as anything else that we’re having.

“A lot of time, I think farmers are able to just rely on the cold weather to help them manage insects to an extent without doing much of anything. But of course, we had a very nice, open fall and not really much of a winter thus far, so I think guys weren’t maybe paying enough attention to their bins, and with the added warm weather, the grain in the bin has stayed fairly warm, and so the insects are doing pretty well this year.”

Grain temperatures should be at least 15 C, and ideally below 10 C, although rusty grain beetles can survive up to -20 C, said Elliott.

“At about 17 or 18 C, you get the insects to stop reproducing and they also stop feeding actively.

“You want to get down to closer to 0 C in the bin if you can, which would have been difficult this year at various times in our fall, but it shouldn’t be too hard in the next couple of weeks, and then you’ll get a lot more mortality there.”

Grain is a good insulator that helps keep the core of the bin warm, said Elliott. The contrast with colder outside temperatures can create drafts of 20 to 25 C even in the middle of January, drawing heat and moisture into the centre of the bin, he said.

“And so, those insects are very, very happy. They’re moving around, they’re reproducing, and they’re feeding.”

Farmers with bins that lack aeration may want to auger the grain into a truck to cool it for a day or two to break up hot spots, he said.

“And if you pop your head in (the bin) and then take a look at the top, you will find that you might see insects roaming around at the top of the bin because that’s the perfect place for them, and you might even see some storage mould starting to form at the top.” doug.ferguson@producer.com

Grain bin monitoring tips from Brent Elliott of the Canadian Grain Commission:

· Monitor bins constantly after harvest; ideally every two weeks. Grain bins are not static environments. Air currents move within the grain due to differences in temperature inside and outside the bin. This tends to create a warm core and can sometimes lead to moisture problems. Storage moulds may occur at the centre top portion.

· Watch for hot spots. Insects thrive in warm grain.

· Ideally, get grain temperature lower than 10 C. Insect feeding and reproduction generally slows or stops at 18 C, and death occurs at 10 C. Getting to 0 C is best because it will kill most insect species. Rusty grain beetles are an exception. They can survive temperatures down to -20 C.

· Aeration is the best tool to cool grain. Ensure the cold air has moved all the way through the grain. If the bin doesn’t have aeration, move the grain into a truck to cool and break up hot spots.

Tags: beetles, grain, Alberta, Эль-Ниньо, British Columbia, durum wheat, insects, warm weather, hot spots, bugs