These larvae will be found in or about infested roots. NCR and WCR larvae may be observed from June through August. Since SCR larvae do not overwinter in Ohio, SCR larvae are not included in the soil rootworm complex. Field Symptoms Rootworm larvae feed on the corn root system causing corn plants to lodge and a subsequent reduction in grain yield. Severe lodging of corn makes harvest difficult and may contribute to additional loss in yield.
Adults feed on silks disrupting pollination if extensive silk clipping occurs prior to pollen shed.
Adults may also feed extensively on corn foliage and weaken the plants. In general, the northern corn rootworm feeds more on the silk than the western corn rootworm, which tends to feed more heavily on the corn foliage. History Western and northern corn rootworms overwinter in the egg stage in fields where corn was grown the previous season. The eggs hatch from late May through June. Thereafter, the larvae pass through 3 larval stages or instars feeding upon the corn root system.