Natural history, ecology, and management of the Mexican bean beetle (Coleoptera: Coccinellidae) in the United States

Abstract

Mexican bean beetle, Epilachna varivestis Mulsant, is an invasive, phytophagous ladybeetle that has occurred in the United States since the late 1800s. In the 1970s, it was a major defoliating pest of soybeans in the eastern United States, before populations mysteriously crashed. Today, the insect remains a devastating pest of Phaseolus species, such as common bean, P. vulgaris, and lima bean, P. lunatus, in geographic locations with moderate summer temperatures and regular rainfall, such as the Mid-Atlantic and southern Appalachian Mountain regions of the United States. Larvae and adults injure plants by consuming leaf tissue, which promotes desiccation and decreases photosynthetic activity. Beetle damage can be successfully mitigated with various insecticides (both conventional and organic), or via augmentative releases of the biological control agent, Pediobius foveolatus (Crawford). Various cultural and mechanical management tactics also exhibit management potential; however, more research is necessary to determine specific criteria for effective implementation of these strategies. This paper will review the general biology of Mexican bean beetle, management options to mitigate crop damage, and its historical timeline as a pest in the United States.