Mexican Bean Beetle: Native Range & Global Spread

Origins & Distribution

The Mexican bean beetle (Epilachna varivestis) is native to the southwestern United States (Arizona, New Mexico, Texas) and Mexico, where it co-evolved with native legumes.

Invasive Expansion

Through accidental transport (contaminated seed, produce, vehicles) and natural dispersal, it has established populations across:

• North America: Eastern U.S. (coast to coast), southern Canada.
• Central & South America: Guatemala to Argentina.
• Europe: First detected 1960s; now in France, Italy, Balkans, spreading north.
• Africa: Reported in South Africa, Kenya, Tanzania.
• Asia: Japan, Korea, China, Southeast Asia.

Impact & Management

Larvae and adults skeletonize bean leaves (soy, snap, lima, cowpea), reducing yields. Biological control (Pediobius foveolatus parasitoid wasp) is effective in some regions. Cultural practices: early planting, trap crops, row covers. Insecticides used where thresholds exceeded.

Climate warming may further expand its range northward in Europe and North America. Monitoring via CABI Invasive Species Compendium tracks new detections.