The Swamp Milkweed Leaf Beetle, Labidomera clivicollis, is one of many colorful insects associated with milkweed. The orange and black coloration is almost universal signs that says "Don't Eat Me" or "I Taste Awful." The Monarch Butterfly, Milkweed Bugs, the Four Eyed Beetle and even the Milkweed Tussock Moth and Caterpillar all use this color pattern. Down South "Queen" and "Soldier" Butterflies are as brilliantly orange and black as the Monarch. There are even species that mimic these to not get eaten, such as the Viceroy which differs from the Monarch in that it's wings are smiling among other things.
Asclepias purpurascens, which is going to flower for the first time in my yard. Worst of all, it has a liking for eating the flower buds instead of the leaves. So I've moved it over to some Asclepias incarnata which is the species the beetle is named after. They also go for Common Milkweed, Asclepias syriaca, and likely others as well.