Shield bugs are members of the superfamily Pentatomoidea of the bug order (Hemiptera). Pentatomoids are generally larger than other Hemipterans, with most having five segmented antennae. They are predominantly herbivorous and are often brightly coloured (Schaefer, 2009 "Prosorrhyncha: Heteroptera and Coleorrhyncha" in Encyclopedia of Insects pp. 839-855).
Sloe Bug, Dolycoris baccarum