Field Identification
A small leaf beetle that punches round holes in soybean and bean foliage and can scar pods; color morphs range from red to yellow to tan with a black triangle behind the head—same pest, different paint jobs.
Adults chew round holes; larvae feed underground on roots and nodules. Overwinters as adults in leaf litter; colonizes early beans in spring.
How to Deal With It
Organic Control Methods
Neem and pyrethrin provide short residual knockdown on adults; kaolin can deter feeding on seedling beans when applied thoroughly.
Ground beetles, crickets, and spiders reduce adults; conserve residue management that supports predators without boosting slugs unduly.
Avoid very early ultra-isolated bean rows; plant perimeter trap rows; rotate with non-legumes.
Row covers on garden beans until flowering; shake adults into water trays.
Scout cotyledons for shot-hole feeding; watch first trifoliates for thresholds.
Let Nature Handle It
Natural Enemies
- Ground beetles
- Crickets
- Spiders
Threat Map