September 29, 2009

Milkweed bug, oncopeltus fasciatus

Did some research and found the following websites and info on this bug at and It is a milkweed bug, oncopeltus fasciatus. Here's some info copied from one of the sites above. "Habitat... Milkweed bugs are usually found in small groups on milkweed plants, often on the underside of the leaves. Milkweed plants sometimes fill entire fields in good years, but usually are found along roadways. The plant produces a milky white sap when a leaf is removed. These plants are large (3-4 feet high) with sprays of small white flowers in the summer. In the fall, seed pods develop which are 4 inches long and 1 1/2 inches wide. When the seeds ripen the seed pods open up releasing the seeds which float on fluffy white parasols. Milkweed bugs can be found on seed pods piercing the wall of the pod to feed on seeds. Predators ... Milkweed bugs have few predators because they concentrate in their bodies bad tasting compounds found in the sap of milkweed plants. The bugs use the bright coloration to advertise their bad taste. Inexperienced birds that taste their first milkweed bug are unlikely to try to eat another orange and black insect! Some insects that do not taste bad use similar color patterns to fool birds. These are known as mimics." HELP - Can anyone tell me what these insects are. They are only on the butterfly weed seedpods. I am assuming they are no problem since they aren't on anything else. I am planning to leave the plant until all the pods have opened and the seeds have floated away on their fluffy parachutes.

1 comment:

lynn'sgarden said...

Wow! I grow asclepias too and have never seen these bugs. They sure are colorful! Pretty butterfly colage in the last post ;)