Illinois Field Crop Applicators Practice Test

At what stage does a corn rootworm start to feed on the silks of corn ears?

1. As adults

2. As larvae

3. During the pupa stage

4. As eggs hatch

The correct answer is: As adults

The correct answer is that corn rootworms begin to feed on the silks of corn ears as adults. This is significant because, at the adult stage, rootworms seek out corn plants to feed on the reproductive structures, particularly the silks, which can impact pollination and ultimately yield. The timing of this feeding behavior is critical for understanding the pest's life cycle and the potential impact on corn crops. Feeding starts after the eggs hatch and larvae initially feed on the roots. Although larvae cause major damage to the root system, they do not feed on silks, which becomes a concern only after they mature into adults. The pupae stage and the egg hatch do not involve feeding on the silks, focusing instead on development and transition phases. Understanding the lifecycle stages of corn rootworms helps in implementing effective management strategies to protect corn yields.