Male red milkweed beetles are often smaller than the females. Click image to enlarge.
These long-horned beetles are unique in several ways. Each compound eye is bisected by an antennae, forming a dorsal and ventral compound eye next to each antenna. In fact, their species name literally means “four eyes.”
Red milkweed beetles are one of the few insect species that can safely feed on milkweed (Asclepias). These beetles sequester the milkweed’s toxic chemicals (glycosides), incorporating them into their body tissues. They advertise their resulting toxicity with their distinct red and black coloration.
Are these beetles poisonous to Milkweed plants?
Hi Sue,
No, they are not. You can find a brief introduction to their relationship with milkweeds at http://www.enature.com/fieldguides/detail.asp?recNum=IS0031.