These shiny black beetles are all over our patio plants, outside walls and door facings. Each one is about 3/8 inches long and has a red/orange blotch in the center of the back. The smaller (younger?) ones lack the blotch. They all have orange undersides and legs. They appear to be eating something but don't seem to be doing any damage to the plants they are on.
Maybe a nymph of a bug in the family Largidae -
http://bugguide.net/node/view/259682/bgimage
Thank you!
