In other jurisdictions, the insects over winter as eggs that hatch early in the spring. Larvae resemble the larvae of the Colorado potato beetle. Research has shown that both the larvae and adults accumulate hypericin that they ingest from the plants. The amount of hypericin in the larvae is enough to make them photosensitive and feeding habits seem to reflect this accumulation. Very young larvae feed only at night and are concealed in terminal leaf buds during the hours of peak sunlight.
Older larvae feed only in the early dawn.
They burrow into the soil during the day and remain there until dawn the next day. Adults feed heavily until mid-late July. Adults are reluctant to fly from plant to plant. When the elytra are opened during flight, light can penetrate the cuticle, activating the hypericin which becomes toxic to them. Adults move about only when threatened with starvation.