European Corn Borer - Ostrinia nubilalis (Hubner)

Dr. Phillip Roberts, Extension Entomologist, The University of Georgia, Department of Entomology, Tifton, GA 31793
Dr. Paul Guillebeau, Extension Entomologist, The University of Georgia, Department of Entomology, Athens, GA 30602

Order Lepidoptera: Famly Crambidae

Description: Adult: female has robust body with 1 inch wingspan. Outer third of wings crossed with dark zig-zags. Male is smaller; outer third of wings has two zig-zags of pale yellow. May be pale-yellow areas on forewings. Larvae: newly hatched larvae are less than 1/8 inch, with five pair of prolegs and a pale yellow body with several rows of small, dark spots. Mature larva reach about 1 inch. Hosts: Corn is preferred but will infest more than 200 plants, including bean, beet, celery, potato, pepper, and tomato. Damage: Typically begin feeding on leaf surface or in the whorl. Larvae then bore down leaf midribs into the stalk. Look for frass or silk near entrance holes. Stalks and stems are weakened and the movements of plant nutrients is impeded. Entrance holes also allow disease organisms to enter the plant.

European corn borer larva Photo by: James Solomon, USFS

European corn borer larva and damage on sycamore Photo by: James Solomon, USFS

Life Cycle: Overwinter as mature larvae in plant debris and pupate in the spring. Moths emerge in April-May. Females lay up to 600 eggs in small masses of 20-30 eggs on the underside of leaves. Eggs hatch in 3-12 days. Complete life cycle is about 4 weeks. Often arefour generations per year.

Control: This pest has many natural enemies, including parasitic flies, wasps, and various predators. Populations are only susceptible to insecticides during the 2- to 3-day period after larvae hatch and feed on leaf surfaces. After they bore into the stalk, insecticide sprays cannot control them. Pay careful attention to the presence of adults and eggs, eggs hatch, and before larvae bore into stems. Organophosphates, carbamates, pyrethroids, and Bacillusthuringiensis are used to control.

In: Roberts, P. M. and G. K. Douce, Coordinators. 1999. Foliage Feeding Insects. A County Agent's Guide to Insects Important to Agriculture in Georgia. Univ. of GA, Col. Ag. Env. Sci., Coop. Ext. Serv., Tifton, GA USA. Winter School Top Fifty Agricultural Insect Pests and Their Damage Sessions, Rock Eagle 4-H Ctr., Jan. 20, 1999.

Selected References and Suggested Readings