Mexican bean beetle

Definition

A leaf-feeding lady beetle (Epilachna varivestis) and major agricultural pest of legumes in North America. Unlike the predatory habits of most Coccinellidae, adults and larvae skeletonize leaves of beans, soybeans, and other Phaseolus species, causing significant yield losses in the eastern United States and irrigated western regions. The species is notable as one of the few herbivorous members of an otherwise entomophagous family.

Etymology

Named for its geographic origin and primary host plant.

Example

In soybean fields of the Mid-Atlantic, Mexican bean beetle populations can defoliate plants so severely that farmers apply targeted insecticides or release the parasitoid wasp Pediobius foveolatus as a biological control agent.

Synonyms

• Epilachna varivestis

Related Terms

• Coccinellidae
• herbivory
• defoliation
• Biological control
• agricultural entomology
• leaf beetle
• Parasitoid
• Integrated Pest Management

Usage Notes

Distinguished from beneficial lady beetles by its herbivorous diet; larvae are yellow, spiny, and feed openly on leaf undersides rather than hunting aphids. Often confused with the spotted cucumber beetle (Diabrotica undecimpunctata howardi), which has a different body shape and feeding pattern. Control strategies differ markedly from those for predatory lady beetles.