If you didn't look at the pictures I posted, you need to. The picture of the bugs that I posted do do a load of damage. Regular ladybugs do not eat milkweed. These do eat the milkweed in the adult and larvae stage. They are not ladybugs. They are Labidomera clivicollis - Swamp Milkweed Leaf Beetle.
http://bugguide.net/node/view/2970
Swamp Milkweed Leaf Beetle
Food
Foliage, flowers, of milkweed, esp. Swamp Milkeed, Asclepias incarnata, but also found on Common Milkeed, Asclepias syriaca. Also on Cynanchum and Sarcostemma.