Evaluation of Mexican Bean Beetle (Coleoptera: Coccinellidae) Host Selection, Survival, and Feeding Injury Among Snap Bean and Lima Bean Cultivars

Abstract

Mexican bean beetle, Epilachna varivestis Mulsant (Coleoptera: Coccinellidae), is a serious pest of snap bean, Phaseolus vulgaris L. (Fabales: Fabaceae), lima bean, Phaseolus lunatus L. (Fabales: Fabaceae), and an occasional pest of soybean, Glycine max (L.) Merr. (Fabales: Fabaceae), in the United States. Past research indicates that some bean cultivars endure greater injury from this pest than others, suggesting that such crops are either more preferred, better hosts, and/or have poorer defenses. This study characterizes injury potential among three snap bean and three lima bean cultivars by measuring ovipositional preference, survival, and feeding injury of E. varivestis in field and greenhouse experiments. Snap beans, as a group, were more preferred and susceptible to injury than lima beans. The purple wax snap bean, Dragon's Tongue, was the most susceptible overall; while the dwarf bush lima bean, Henderson, was the least susceptible. The results of this study will aid in the development of integrated pest management strategies for E. varivestis, while also providing broader biological information for future research on this pest and others.

Keywords: Epilachna; biology; host preference; snap bean; trap crop.