Pulse School: Scout early, scout often, for pea leaf weevils

Notching on leaves caused by pea leaf weevils.

If you’re a pea grower, you’ve seen it: the notching that almost looks like someone took a hole puncher to your plants as they unfold.

That feeding is characteristic to the pea leaf weevil.

As Lyle Jensen with AgroPlus Inc explains in this Pulse School episode, you’ll see the pea leaf weevil during the day, but they are quite hard to spot as they are often only a couple millimetres in size, and often are similar in colour to the soil — making them practically invisible.

A mild winter — like parts of the Prairies saw this year — could be indicative of higher pressure levels in the 2022 growing season.

“There wasn’t a whole lot of time we were below minus 30. So there’s a good likelihood of heavy pressure this year,” says Jensen.

Damage from the weevil itself can be quite significant, although the visible damage — the above ground damage from the leaf notching — in the grand scheme of things is very minor, says Jensen.

“It’s the eggs that they’re laying, and the larvae themselves that causes the damage underground. And they do that by feeding on the nodules underground, depriving the crop of its source of nitrogen,” he says.

Often once the eggs have been laid, the damage has been done. So when it comes to thresholds, there’s not a ton of control options.

“Spraying at any point is more of a revenge activity to make you feel better,” Jensen explains. “It probably won’t have much of an impact on what’s already happened. You’re much better off to protect yourself with a seed treatment to start with.”

Check out the full episode below: