Ostrinia nubilalis

Hübner, 1796

European corn borer, European corn worm, European high-flyer

The is a non-native pest of corn and other crops in North America, Europe, and North Africa. Larvae bore into corn plants, causing damage to stems, ears, and leaves. Two strains exist: the Z strain (prevalent in the midwestern U.S.) and the E strain (more abundant in the eastern U.S. and Europe). Widespread adoption of Bt corn since 1996 has dramatically reduced in North America, with over 90% suppression reported in some regions.

Ostrinia nubilalis by the Smithsonian. Used under a CC0 license.

Ostrinia nubilalis01 by wikipedia. Used under a Attribution license.

Pronunciation

How to pronounce Ostrinia nubilalis: /ɒˈstrɪniə njuːbɪˈlɑːlɪs/

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Identification

can be distinguished from similar Crambidae (such as Anania hortulata, Sitochroa verticalis, and Pleuroptya ruralis) by geometric morphometric analysis of wing venation patterns. Nine landmarks at junctions in the forewing central region provide 97% in identification. The two strains (Z and E) differ in female pheromone genes and can be distinguished by pheromone analysis.

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Habitat

Agricultural environments, primarily corn (maize) fields. Larvae overwinter in lower stems and plant remains. occur in fields and surrounding areas during periods.

Distribution

Native to Europe; introduced to North America (first reported Massachusetts 1917). Present in: Europe (widespread including UK, France, Germany, Italy, Poland, Spain, and others), North Africa (Algeria, Egypt, Libya, Morocco, Tunisia), Asia (Iran, Israel, Lebanon, Syria), and North America (Canada: Alberta, Manitoba, New Brunswick, Newfoundland, Nova Scotia, Ontario, Prince Edward Island, Quebec, Saskatchewan; USA: Alabama, Colorado, Connecticut, Delaware, Georgia, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maryland, Massachusetts, Michigan, Minnesota, Mississippi, Missouri, Nebraska, New Hampshire, New Jersey, New York, North Carolina, North Dakota, Ohio, Oklahoma, Pennsylvania, Rhode Island, South Carolina, South Dakota, Tennessee, Vermont, Virginia, West Virginia, Wisconsin).

Seasonality

emerge in May and June. One to three per season occur, with the second generation generally causing the most damage. hatch within approximately one week. Larval development takes three to four weeks before .

Diet

Larvae feed on maize (Zea mays) plants, boring into stems, ears, and leaves. Also feeds on millet, sorghum, Indian hemp, hops, and Artemisia. Gut (Firmicutes and Proteobacteria in the ) contribute to cellulose degradation of lignocellulose-rich maize tissues.

Host Associations

Zea mays - primary Maize; main agricultural causing significant economic damage
Panicum miliaceum - Millet; original native in Europe, including broom corn
Sorghum bicolor - Sorghum
Cannabis sativa - Indian hemp
Humulus lupulus - Hops
Artemisia - Artemisia

Life Cycle

Fully grown larvae overwinter in lower stems and plant remains. occurs in spring. emerge May-June. Females lay in clumps on undersides of lower leaves. Larvae bore into plants, feed for 3-4 weeks, then pupate within ears or stems. Second adults emerge in early summer; one to three generations per year depending on region.

Behavior

Females show oviposition preference for corn plants grown in conventionally managed soil over organically managed soil in whole-plant choice tests. This preference appears linked to lower magnesium and calcium concentrations in conventionally grown plants. E-strain show stronger preference for conventional fields than Z-strain moths. are attracted to light.

Ecological Role

Major agricultural pest. Subject to by , particularly Trichogramma , which parasitize . Part of complex agroecosystem interactions involving soil management, plant health, and pest . Gut enable lignocellulose degradation, potentially facilitating nutrient acquisition from plant tissues.

Human Relevance

Causes up to $2 billion in damage in the United States alone. Major pest of corn and over 200 other crops. Management relies on Bt corn, , and . Bt corn adoption has reduced by over 90% in some regions and provided spillover benefits to non-Bt crops (pepper, green beans, sweet corn) through area-wide pest suppression. Resistance to Bt proteins has evolved in some populations, requiring resistance management strategies including crops.

Similar Taxa

Helicoverpa zeaCorn earworm; similar pest of corn but belongs to Noctuidae, has different damage patterns (ear feeding rather than stem boring), and different seasonal activity.
Anania hortulataSmall magpie ; similar Crambidae member with yellowish-brown wing coloration, found in corn fields simultaneously, distinguished by wing venation patterns.
Sitochroa verticalisCrambidae member with similar coloration and markings, found in corn fields, distinguished by geometric morphometric analysis of wing venation.
Pleuroptya ruralisMother of pearl moth; Crambidae member with somewhat similar appearance, distinguished by wing venation landmark analysis.

More Details

Pheromone strains

Two distinct strains differ in female genes: Z strain (Z11-14:Ac pheromone component) prevalent in midwestern U.S., and E strain (E11-14:Ac) more abundant in eastern U.S. and Europe. Strains show differential responses to soil management in field trapping studies.

Unintentional attract-and-kill mechanism

Research demonstrates that preferentially lay on corn grown in conventionally managed soil, which often contains Bt corn. This creates an unintentional attract-and-kill system where pests are drawn to toxic crops, potentially enhancing control.

Gut microbiota function

Larval gut bacteria (primarily Firmicutes and Proteobacteria in ) possess -active enabling cellulose degradation. Diet dramatically affects composition: larvae fed artificial diets versus maize plants show distinct bacterial .

Resistance management

Evolution of resistance to Bt proteins (including Cry1Fa) has been documented. strategies (separate non-Bt fields or seed blends) are employed to maintain susceptibility in . Effectiveness varies by larval movement and mating patterns.