Mole Cricket Larvae and Adult-Clemson University
They also look like bean leaf beetles but they have many more spots. Eggs are laid in clusters (40-50) on undersides of leaves, yellow and are shaped like minature marshmallows. Nymphs are yellow with spines in rows on their backs.
Eggs, Nymphs and Larvae-University of Kentucky
Adults emerge in spring, feed for a week or so and then lay eggs on undersides of leaves. They can lay up to 500 eggs per year! In northern climates they have one generation per year but more in warmer climates.
Severe damage on beans-James Castner University of Florida (see that lady bug there at work)
Diet and Damage
They attack all varieties of beans and cowpeas, vetch and alfalfa. They feed on the undersides of leaves and early detection is critical. The uppersides of the leaves don’t look marred in early stages. Later on leaves will have brown skeleton-like holes, eventually leaves will dry up and drop. They don’t eat the veins of leaves. If there is a severe infestation then they will also attack the bean pods and the stems.
1) Hand Pick
Whenever you see them destroy immediately and destroy any eggs you find.
2) Water Spray
A very hard spray of water will kill the beasts as well as hard rain and extremely hot summers. If there is a very cold winter, most of the beetles will not survive.
3) Remove Plant Debris
Keeping your garden clean and free of debris will help control these guys. Problem with this is you will also destroy a habitat for ladybugs so if your problem is not too severe then leave a spot for those great ladybugs to overwinter.
Parasitic wasps, parasitic flies, lady bugs and soldier bugs.
5) Companion Plants
Potatoes, nasturtium (they do attrack black aphids sometimes) and marigolds.