Pest Status: Mexican bean beetles are the only member of this family that is considered a serious pest.
Appearance: The copper-colored adults resemble large lady beetles. They are 1/4-inch long with eight black spots on each wing.
Life Cycle: Adults overwinter and emerge when temperatures increase, usually mid-summer. After feeding, the females lay their eggs on the undersides of foliage. They hatch within a week during warm weather. The larvae feed for two to five weeks before pupating. When pupating, a larva fastens the tip of its abdomen to a part of the plant and sheds its larval skin. The pupal stage lasts for a week before the adult emerges.
Where to Collect: Adults are most commonly encountered on garden and field beans and cowpeas.
Purdue Extension Entomology, 901 West State Street, West Lafayette, IN 47907 USA, (765) 494-4554