I found several of these Milkweed Tussock Moth Caterpillars eating my outside Hoya cumingiana today.  It makes total sense as both of these plants are in the Asclepiadaceae family.  I don’t really care about damage to the plant as it is headed to the waste bin anyway, but the caterpillars are extremely interesting.

The Milkweed Tussock Moth Caterpillar obtain cardiac glycosides, a powerful toxin from their food and store it in their bodies.  Birds will try one of these; wretch, immediately vomit it up, and because of the bright colors of the caterpillars will avoid it in the future.