northern corn rootworm beetle

not listed

NNR - Unranked

not listed

Northern corn rootworm beetle is a small skeletonizing leaf beetle.

The body is 3 ⁄16″ to ¼″ long, moderately elongated, and moderately flattened. When viewed from above, the head and most of the legs are clearly visible. Newly emerged adults are cream-colored to light brown, soon turning greenish-yellow.

The mouthparts project from the front of the head. The base of the antennae are close together, about level with the middle of the eyes. The antennae are flexible, and can project in various directions.

The pronotum is pale greenish-yellow and narrower than the elytra. It has a pair of depressions and a distinct lateral margin.

The elytra are pale greenish-yellow and hairless, with distinct, longitudinal, parallel ridges. They do not have stripes or spots.

When viewed from above, the third leg segment (femur) is greenish-yellow, never black or lined with black. The last part of each leg (tarsus), corresponding to the foot, has five segments but the fourth segment is minute, making it appear that there are only four segments.

Total length: 3 ⁄16″ to ¼″

Corn fields and adjacent areas

Mid-July to late September

Adults emerge from mid-July to late August. They are most active at dawn and dusk. The female deposits its eggs in the soil within 6″ of the soil surface at the base of a corn plant. It may live up to 80 days and deposit up to 1,000 eggs.

The eggs overwinter in the soil. They hatch in early to late June. Young larvae feed on fine rootlets, older larvae invade the root core. They pupate in the soil within 4 to 6 weeks, and emerge as adults 5 to 10 days later.

Roots of corn (Zea mays)

Mostly leaves and silk of corn (Zea mays); also plants of the Poaceae (grass), Asteraceae (aster), Fabaceae (pea), and Cucurbitaceae (gourd) families .

Sources

Common. Major pest on corn crops.

Location: Hutchinson, MN

green, on volunteer sunflower

Location: Slinger, Wisconsin

Location: Woodbury, MN