European Corn Borer on Wheat

Ostrinia nubialis (Hubner)

Description: European corn borer moths hold their wings back at an angle when resting and are characterized by having two wavy or zigzag lines across the wings. The wingspan is about 1 inch. Eggs are laid in masses, with the individual eggs overlapping each other. The larva gets about 1" long, with a pale body and characteristic pairs of dark spots running its length. Damage is first noticed on wheat when heads blanch prematurely. European corn borer damage can be diagnosed by the hole in the stem, usually at a node. There is often fecal material exuding from the hole. Split the stem to find the larva inside.

Biology: European corn borer overwinters as a larva in corn stubble or other hosts. After pupating in the residue in the spring, the moths emerge, mate, and each female lays about 500 eggs in small masses on the underside of host plant leaves. This first spring generation can attack wheat. Eggs hatch in 3-12 days and the small larvae feed on leaves. Larger larvae tunnel into the wheat stem. There are four generations per year.

Management: European corn borer is only an incidental pest of wheat in South Carolina. It occurs sporadically and in low enough numbers that no cultural controls are recommended other than maximizing crop compensation ability through good agronomic practices. Even if an infestation caused economic injury, the damage would be done before it could be detected and chemical control would not be feasible.

Reference: Hunt, T. N. and J. R. Baker. 1982. Insect and related pests of field crops. AG-271. North Carolina Agricultural Extension Service. 214 pp.

Prepared by Jay W. Chapin, Extension Entomologist/Professor,  Department of Entomology, Soils, and Plant Sciences, Clemson University, Edisto Research & Education Center

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