Western corn rootworm

Definition

A subspecies of chrysomelid beetle (Diabrotica virgifera virgifera) and among the most economically significant corn pests in North America. Larvae feed primarily on corn roots, causing lodging and yield loss, while adults feed on silks and pollen. The species exhibits strong host fidelity to maize and has evolved resistance to multiple management strategies including crop rotation and Bt toxins.

Etymology

From geographic range (western North America), host plant (corn/Zea mays), and larval feeding site (roots).

Example

In Iowa cornfields, heavy infestations of Western corn rootworm larvae can prune roots so extensively that plants topple during summer storms; adult beetles later emerge to clip silks, interfering with pollination.

Synonyms

• Diabrotica virgifera virgifera

Related Terms

• Northern corn rootworm
• corn rootworm
• Diabrotica
• Chrysomelidae
• crop rotation
• Bt resistance
• root herbivory
• Integrated Pest Management

Usage Notes

Often abbreviated WCRW or WCR in agricultural literature. Distinguished from the Northern corn rootworm (D. barberi) by geographic distribution and subtle morphological differences; the two species overlap broadly in range and may hybridize. The name "western" reflects historical distribution patterns rather than current range, which now extends eastward. Management discussions frequently treat "corn rootworm" as a complex including both species.