Tortoise beetles overwinter in the adult stage, hiding themselves in dry sheltered places under bark or trash. The adults emerge somewhat later in the spring, usually in the last half of May or early June. They are first noticed occasionally by their feeding, but more often by their brilliant colors during mating. Upon hatching, the larvae begin to feed. At first glance, they appear to be a speck of moving dirt or excrement.
Adults emerge in a week or so and feed before finding shelter for the winter.
There is one generation per year, possibly two with some species. It is doubtful that you will find an insecticide registered for tortoise beetles because of their low economic importance except on soybeans. In Vermont, tortoise beetles occur mostly on weeds and are thus beneficial. Larvae carry excrement. Also feeds on milkweed.