The larva has 4 pairs of abdominal prolegs. It attaches a soil-covered, silken tube to the plant just below the soil level and from this tube tunnels into the stem. Seedlings may be killed or damaged to the point that they will lodge later in the season. Damage is most common on sandy soils following periods of drought. There are usually 6 black spots on the wing covers.
Some color phases have but two small black spots at the tip of the wing covers.
This beetle damages soybeans primarily by feeding on the leaves but will sometimes rasp on the outside of the pods. The female moths lay clusters of about ISO whitish eggs, usually on the undersides of leaves. The egg masses are covered with fine scales from the female moth. Larvae may feed on leaves, blooms or pods. Most damage occurs when they eat the beans out of the pod.