Northern Corn Rootworm: How to Control Them Naturally

Northern Corn Rootworm

Diabrotica barberi

Pale to green beetles and slender larvae that feed on corn roots, causing stunted, misshapen plants. There is 1 generation a year.

How to control northern corn rootworm

Use: Scanmask Spray (also works: Scanmask Topdressing, Ecomask Spray, Ecomask Topdressing, Garden Pack)
When: Late May to mid-July, while the larvae are in the soil.
Where: Around crops.

Shop Scanmask Spray

What it looks like

Adult northern corn rootworm beetles are pale or green, depending on their age. The larvae are slender and yellowish white with dark heads.

The eggs spend the winter in the soil and hatch in late spring or early summer. The larvae feed on roots for about 4 to 6 weeks before changing into pupae, and the adults come out about a week later, in mid to late summer. Northern corn rootworms usually have 1 generation per year.

Damage

Northern corn rootworms are a major pest of corn. Both the larvae and the adults can badly damage plants and roots. The larvae do the most harm as they feed on the roots, while the adult beetles attack every part of the corn plant, including the leaves and silks.

The damage can keep plants from taking up nutrients, leaving them stunted and misshapen, and makes them more likely to get diseases.

How nematodes help

The beneficial nematodes in BioLogic's products hunt down and kill corn rootworm larvae in the soil. Killing the rootworms as larvae stops the life cycle, so new adults don't emerge.

How to apply

Treat with Scanmask from late May to mid-July, applying it to the soil around your crops. Ecomask also works. The larvae hatch from late May to mid-June and spend 4 to 6 weeks in the soil, and that is when nematodes can kill them. The Garden Pack includes Scanmask Spray and the Nema-Jet Sprayer.

Also see the southern corn rootworm and western corn rootworm.

See How to apply for step-by-step directions, or use the calculator on the Scanmask Spray page to see how much you need.