Wireworms can quickly weave a destructive path through your cereal stand. Knowing what symptoms to look for can help you identify and take steps to protect your crop from this destructive pest.
You might start off by seeing bare patches that can be small, one or two-metre gaps, or larger areas where you have thin stands with stunted and missing plants.
Wireworms tend to feed along seed rows, and are attracted to germinating seeds, roots and seedlings. Look for stems and roots that have been heavily damaged — even shredded — rather than cut off cleanly.
Other telltale signs of wireworm feeding include: plants that emerge normally and then suddenly die around the one= or two-leaf stage, or seedlings that put out extra tillers in an attempt to survive.
Before seeding, try to get a sense of wireworm pressure by laying out wireworm bait ball traps.
Wireworm bait balls can be prepared by combining oatmeal, honey and water, creating a baseball-sized ball. The traps are designed to produce CO2, which attracts wireworms looking for their next meal.
Pick a few random areas of your field and bury the bait balls about four to six inches below the soil surface. Mark your traps with flags, and then check back in seven to 10 days.
Depending on your wireworm pressure, you might see several holes chewed through the bait balls, or wireworms still actively feeding on them.
Mark Mercier is a seedcare specialist with Syngenta Canada.