European Corn Borer
Encyclopedia
The European corn borer (Ostrinia nubilalis), also known as the European high-flyer, is a pest of grain, particularly maize
. The insect is native to Europe
, originally infesting varieties of millet, including broom corn. The European corn borer was first reported in North America in 1917 in Massachusetts
, but was probably introduced from Europe several years earlier. Since its initial discovery in the Americas, the insect has spread into Canada
and westward across the United States
to the Rocky Mountains
.
European corn borer caterpillars damage the ears of corn, as well as the stalks, by chewing tunnels, which cause the plants to fall over. Biological control agents of corn borers include the hymenopteran parasitoid Trichogramma
spp., the fungus Beauveria bassiana
and the protoza Nosema pyrausta.
Bt corn, a variety of transgenic maize
, has had its genome modified to include a gene from the Bacillus thuringiensis
ssp. kurstaki. As a result, the corn variety produces a toxin which affects the corn borer, and as critics have pointed out, beneficial predatory insects as well.
Immature maize shoots accumulate a powerful antibiotic substance, DIMBOA
that serve as a natural defense against a wide range of pests and is also responsible for the relative resistance of immature maize to the European corn borer.
Female corn borer moths lay clusters of eggs on corn leaves, usually on the underside. The egg masses, or clusters, are laid in an overlapping configuration and are whitish-yellow in color. As the larvae develop inside their eggs, the eggs become more and more transparent and the immature caterpillar black heads are eventually visible. The caterpillars hatch by chewing their way out of the eggs.
Maize
Maize known in many English-speaking countries as corn or mielie/mealie, is a grain domesticated by indigenous peoples in Mesoamerica in prehistoric times. The leafy stalk produces ears which contain seeds called kernels. Though technically a grain, maize kernels are used in cooking as a vegetable...
. The insect is native to Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
, originally infesting varieties of millet, including broom corn. The European corn borer was first reported in North America in 1917 in Massachusetts
Massachusetts
The Commonwealth of Massachusetts is a state in the New England region of the northeastern United States of America. It is bordered by Rhode Island and Connecticut to the south, New York to the west, and Vermont and New Hampshire to the north; at its east lies the Atlantic Ocean. As of the 2010...
, but was probably introduced from Europe several years earlier. Since its initial discovery in the Americas, the insect has spread into Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
and westward across the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
to the Rocky Mountains
Rocky Mountains
The Rocky Mountains are a major mountain range in western North America. The Rocky Mountains stretch more than from the northernmost part of British Columbia, in western Canada, to New Mexico, in the southwestern United States...
.
Trichogramma
The wasps of genus Trichogramma, commonly known as "stingless wasps", are some of the most widely-studied agents of biological control in the field of entomology. Trichogramma wasps are tiny Hymenopteran insects, measuring 1 millimeter in length or less, that parasitize the eggs of many types of...
spp., the fungus Beauveria bassiana
Beauveria bassiana
Beauveria bassiana is a fungus that grows naturally in soils throughout the world and acts as a parasite on various arthropod species, causing white muscardine disease; it thus belongs to the entomopathogenic fungi. It is being used as a biological insecticide to control a number of pests such as...
and the protoza Nosema pyrausta.
Bt corn, a variety of transgenic maize
Transgenic maize
Genetically modified maize has been deliberately genetically modified to have agronomically desirable traits. Traits that have been engineered into corn include resistance to herbicides and resistance to insect pests, the latter being achieved by incorporation of a gene that codes for the...
, has had its genome modified to include a gene from the Bacillus thuringiensis
Bacillus thuringiensis
Bacillus thuringiensis is a Gram-positive, soil-dwelling bacterium, commonly used as a biological pesticide; alternatively, the Cry toxin may be extracted and used as a pesticide. B...
ssp. kurstaki. As a result, the corn variety produces a toxin which affects the corn borer, and as critics have pointed out, beneficial predatory insects as well.
Immature maize shoots accumulate a powerful antibiotic substance, DIMBOA
DIMBOA
DIMBOA is a naturally occurring hydroxamic acid, a benzoxazinoid. DIMBOA is a powerful antibiotic present in maize and related grasses, particularly wheat and serves as a natural defense against a wide range of pests including insects, pathogenic fungi and bacteria.In maize DIMBOA functions as...
that serve as a natural defense against a wide range of pests and is also responsible for the relative resistance of immature maize to the European corn borer.
Description
The corn borer moth is about one inch long with a one inch wingspan. The female moth is light yellowish-brown with dark, irregular, wavy bands across the wings. The male is slightly smaller and darker in coloration. The tip of its abdomen protrudes beyond its closed wings. The fully-grown larva is three-quarters to one inch in length. This borer is usually flesh-colored, but may range from light gray to faint pink, with conspicuous small, round, brown spots on each segment.Female corn borer moths lay clusters of eggs on corn leaves, usually on the underside. The egg masses, or clusters, are laid in an overlapping configuration and are whitish-yellow in color. As the larvae develop inside their eggs, the eggs become more and more transparent and the immature caterpillar black heads are eventually visible. The caterpillars hatch by chewing their way out of the eggs.
External links
- European corn borer on the UFUniversity of FloridaThe University of Florida is an American public land-grant, sea-grant, and space-grant research university located on a campus in Gainesville, Florida. The university traces its historical origins to 1853, and has operated continuously on its present Gainesville campus since September 1906...
/ IFASInstitute of Food and Agricultural SciencesThe University of Florida’s Institute of Food and Agricultural Sciences is a federal-state-county partnership dedicated to developing knowledge in agriculture, human and natural resources, and the life sciences, and enhancing and sustaining the quality of human life by making that information...
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