The eggs overwinter and hatching begins in early June. Larger larvae feed on the brace roots, reducing the stability of the plant, causing it to lodge or gooseneck. Scouting for corn rootworm in the spring is extremely difficult as eggs and larvae are almost impossible to find in the soil. Instead, searching for adults in August will enable you to determine what egg populations you will have in your soil the following spring. If in last August you detected a high number adults or experienced extensive goose-necking, consider soil applied insecticide treatments including Force, Counter or Lorsban this spring if corn is to be replanted in that field.
Crop rotation is thus far superior to insecticides for reducing rootworm populations.
If crop rotation is not practical, it may be necessary to treat second-year corn, especially on clay soils. This new variant, now residing in the US but not yet sited in Ontario, lays its eggs in crops other than corn so that its offspring are provided for when you rotate into corn the next year. As a reminder, begin scouting for cutworm damage in your corn fields as soon as the crop emerges. Pay particular attention to those areas of your field that had heavy patches of weeds present this spring before planting. Preventative soil applied treatments at planting time are not as effective as rescue treatments.