With harvest underway and grain going into the bins, it's time to be thinking of insects found in stored grain. According to provinical entomologist John Gavloski, there are two types of pests to be looking for: rusty grain beetle and foreign grain beetle.

"Rusty grain beetle [is] a very tiny grain beetle that feeds directly on the grain itself," he says. "Foreign grain beetle [is] about the same size as rusty grain beetle — really you have to use a microscope to tell the differences between them — but one difference is foreign grain beetle feeds only on mould, it doesn't feed on healthy grain. So if a farmer has it in their bin, usually it means there's damp or wet grain."

He says in the case of foreign grain beetle, producers need aerate or move their grain to get rid of the mould problem.

Stored grain insects aren't picked up from the field during the harvest. Generally they get into stored grain because they're already in the bin or farm equipment.

"In that case, we'd be looking at making sure any remaining grain has been cleaned out and the bin has been thoroughly cleaned before new grain is put in. Aside from the bin itself, the beetles can be in the farm equipment, either in the combines themselves, in augers, grain trucks — anything used to move the grain. So any of these areas that would have grain leftover from a previous year, make sure you get rid of that old grain before you use equipment to move this year's grain," he says.

Gavloski also reccommends checking bins for cracks or holes bugs could get into, and keeping grain below 15 degrees Celsius to prevent beetles from reproducing.

He says stored grain insects prefer cereal grains, and don't do well in oilseeds like canola or flax because there is a higher fat to carbohydrate ratio.