The challenge of the crop manager is to distinguish when egg laying and larval populations can be tolerated or they need to be controlled. Description Full-grown larvae of the European corn borer vary in color from gray to creamy white. The body is covered with numerous dark spots. The head is black. Adult are straw-colored with a 1 inch wingspread.
Males are slightly smaller and darker.
Females lay eggs on the underside of the leaves, near the midvein. The eggs, when laid, overlap like fish scales. As the eggs develop, they change from white to a creamy color. Cycle European corn borers pass the winter as full-grown larvae in corn stalks, corn cobs, weed stems, or in other cornfield debris. The larvae pupate in late May and June, and moths begin to emerge in June and continue to emerge well into July.