Protect Cereals from Wireworm Pressure

Cereal pest management plans can make or break plant stands and emergence, especially if wireworms are present in the soil. Wireworms are known to cause up to 100% yield loss, making them one of the most damaging pests in cereal crops in the Pacific Northwest and Northern Plains regions.

To successfully manage wireworms, it’s important to understand the species, how they damage crops and how to prevent infestations.

What Are Wireworms and Why Are They a Problem?

Wireworms are copper-colored, hard-bodied larvae with three pairs of legs near their heads. As they mature, they grow into click beetles, which are typically black or dark brown with unusually long bodies. Click beetles get their name from the distinctive sound they produce when flipped onto their backs.

Wireworms overwinter and begin feeding on seedlings early in the spring when the ground is wet and cool (50-60 degrees Fahrenheit). This is especially common in regions like the Pacific Northwest, where wireworms can start damaging young plants during emergence and stand establishment.

In the Northern Plains, wireworms feed on cereal crops through June and July when soil temperatures reach 75-80 degrees F. Depending on the species and environmental conditions, wireworms can persist in the soil for as long as 2 to 10 years to complete their lifecycle.

Wireworm Damage In Action

Wireworms move up through the soil profile because they are attracted to carbon dioxide (CO2) released by developing seeds and seedlings. Once the wireworms move into the developing crop, they feed linearly, moving from plant to plant to spread damage across the field.

Some indications that your crop has wireworm damage are bare or tan-brown patches where wireworm feeding has interrupted normal crop establishment. Emerged crops often have stunted, wilted stands and be at higher risk for disease infection.¹

Wireworm populations can increase rapidly if left uncontrolled, potentially exceeding one million per acre resulting in significant crop damage.

A few factors that increase the potential for wireworm damage include:

• Poorly managed field margins can provide ideal conditions for click beetles.
• Not knowing wireworms are present can lead to unexpected losses.
• Not rotating between crops can increase wireworm pressure in dryland cereals.

Preventing Wireworm Damage

Practicing crop rotation and scouting your fields can help set your cereal crops up for a strong start.

Planting treated seed is another method for managing wireworms. Seed treatments can protect developing seedlings so they can emerge evenly and have strong stands.

When to Use a Seed Treatment for Wireworms

You can determine the risk of economic damage to your crop by scouting for wireworms prior to planting. Start in fields with a history of excessive weed pressure, bare patches, or low grain yields. The shovel or modified bait trap methods are two options to scout wireworms.

Bait trap results can help inform your seed treatment decisions using the chart below.

A new wireworm management solution is coming soon to cereal and pulse crops and will feature the active ingredient isocycloseram. Isocycloseram will be an Insecticide Resistance Action Committee (IRAC) Group 30 active ingredient that, upon registration, will act by contact and ingestion and has no known cross resistance to other insecticides.

Be the first to learn more about this upcoming product.

PLINAZOLIN is not yet registered for sale or use in the U.S. and is not being offered for sale.

¹ Foliar symptoms of wireworm damage can appear similar to other early-season pests and diseases and should be confirmed by soil sampling.