Do You Have Wireworms? Here’s How to Find Out Before They Cause a Problem

Bare patches in cereal crops are one of the more frustrating things to discover mid-season — and wireworms are a common culprit. The good news is there’s a simple, low-tech scouting method that can help you get ahead of the problem before seeding even begins.

What Are Wireworms?

Wireworms are the larval stage of click beetles. They live in the soil and feed on seeds and seedling roots, causing thin, patchy stands — especially in cereal crops. Because they’re underground, damage often shows up before you ever see the pest itself.

Scouting with Bait Traps

Bait traps — sometimes called baitballs — are an effective way to assess wireworm populations before or during the growing season. By concentrating an attractive food source in one spot, they draw wireworms in from the surrounding soil, giving you a much clearer picture of what’s present in a field.

The basic approach involves mixing rolled oats with a small amount of honey to create an attractant, forming it into a ball roughly the size of a baseball, and burying it several inches into the soil. After about 10–14 days, you dig up the trap and check for wireworms. The number of worms you find helps indicate the level of risk in that area of the field.

As a general guide, finding a small number of wireworms suggests moderate pressure worth monitoring, while higher counts indicate a more significant population that may warrant a management response.

Why It Matters

Scouting before seeding gives you time to make informed decisions — whether that’s adjusting seed treatment choices, targeting higher-risk areas, or simply knowing what to watch for once the crop is in the ground.

If you’re seeing unexplained bare patches year after year in the same areas, it’s worth investigating wireworms as a potential cause. Talk to your agronomist about whether bait trap scouting makes sense for your fields this season.

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Ag Grow Consulting provides independent agronomy services across Saskatchewan. Our agronomists work directly with growers through every stage of the season.