European Corn Borer (Ostrinia nubilalis)

Life stages: eggs, larvae, pupae, adult moths.
The European corn borer is a sporadic pest of potatoes, usually attacking the crop in cool seasons when corn development is delayed. Female moths lay egg masses on the underside of the leaves of potato plants. Larvae emerge after 3–9 days, depending on temperature. They feed on the leaves for a few days and then bore into the stem of the plant, destroying the pith and the vascular tissue. Larvae complete their development in the stem.
Fully grown larvae overwinter in stems left in the field after harvest. In the spring, larvae pupate and later emerge as adults.