Odd looking little flat beetles in the same subfamily (Cassidinae) as the also unusual looking tortoise beetles. Both these and the tortoise beetles are in the Chrysomelidae family which has some of the most beautifully coloured and patterned beetles. This pair more than likely belong to the species B. nervosus as this is, I think, the only species that lives this far north. It is native to the area, but the group as a whole is more neotropical in distribution with only three species native to North America.