Striacosta albicosta

Larvae can be distinguished from similar corn ear-feeding pests by specific injury patterns and morphology. Unlike corn earworm (Helicoverpa zea), which typically feeds from the tip of the ear downward, western bean cutworm larvae often enter through the side of the ear and may feed on multiple kernels. Larvae have a tan to pinkish body with distinct dark stripes behind the head and a dark head capsule. Full-grown larvae reach approximately 40 mm. Adults are tan to brown moths with a distinctive white stripe along the costa of the forewing, visible when at rest.

Agricultural landscapes dominated by corn and dry bean production. Prepupal and pupal stages occur in soil. The species thrives in areas with suitable host crop availability and soil conditions for overwintering.

Native range: western Great Plains of the United States (western Nebraska, Kansas, Idaho, eastern Colorado). Expanded range: since early 2000s, eastward through Iowa, Minnesota, Illinois, Missouri, Indiana, Wisconsin, Michigan, Ohio, Texas, New York, and into southern Canada and Mexico. Currently restricted to North America, though climate modeling indicates suitable conditions for establishment exist in Europe, Asia, Oceania, South America, and Africa.

Larvae feed on reproductive parts of corn (Zea mays) and dry beans (Phaseolus vulgaris), including kernels, silks, and developing seeds. Adult feeding habits are not documented in available sources.

• Zea mays - primary hostcorn; major crop host causing up to 40% yield loss
• Phaseolus vulgaris - primary hostdry beans; secondary crop host causing up to 10% yield loss

Prepupal and pupal stages occur in soil. Complete details of egg, larval instars, and adult emergence timing are not documented in available sources.

Larvae are nocturnal feeders on corn ears and bean pods. The species has shown significant range expansion behavior, spreading eastward from its native western range beginning in 1999/early 2000s. Adults are nocturnal and attracted to light.

Agricultural pest causing direct yield losses and facilitating secondary damage. Larval feeding creates entry points for fungal pathogens and other insects, reducing grain quality and marketability. In the Great Lakes region of the U.S. Corn Belt, it serves as a major pest species that Vip3Aa Bt toxin effectively controls.

Significant economic pest of corn and dry bean production. Management relies on Bt transgenic corn, but resistance to Cry1F protein has been documented, reducing efficacy of single-toxin varieties. Vip3Aa toxin remains effective in some regions. Monitoring and proper identification of larval injury are critical for integrated pest management decisions. Range expansion has increased its importance in eastern U.S. corn production areas.

• Helicoverpa zeaBoth feed on corn ears; H. zea typically feeds from ear tip downward while S. albicosta enters from side and may feed on multiple kernels; H. zea has more variable coloration and lacks distinct head stripes
• Spodoptera frugiperdaBoth are noctuid pests of corn; fall armyworm has distinctive inverted Y on head capsule and more gregarious early instar behavior; injury patterns differ in frass characteristics and feeding location

• pest
• agriculture
• corn
• dry beans
• Bt resistance
• range expansion
• Noctuidae
• Lepidoptera

• BugGuide
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• Catalogue of Life
• Whodunit? Solving Corn Pest Mysteries When Suspects Have Fled the Scene
• The Problems Driving Resistance to Bt Crops—and Some Proposed Solutions
• Striacosta albicosta Archives - Entomology Today
• Modeling of suitable geographic areas for Striacosta albicosta in corn and dry bean crops under climate change scenarios.