Bean beetle adults are yellow brown, 1/4" long, with 16 black spots; they are frequently mistaken for lady beetles but lady beetles have a varying number of spots. The larvae are yellow orange, spined, 1/3" long. Both adults and larvae prefer beans. They skeletonize leaves and can strip a plant to its stems quickly.
Kaolin clay, which forms a barrier film when sprayed on fruits and vegetables, can be used to deter insect damage. We recommend Surround At Home Crop Protectant.