I have just found what I think I have identified as Milkweed bugs on my Autumn Haze Clematis. Are they harmful to the plant, and if so, how do I get rid of them?

Thanks!

I wonder if they might actually be boxelder bugs....Boxelder bugs (Leptocoris sp.) are brownish black with red or orange stripes on their wings. They are about ½ inch long at maturity. When crushed, the boxelder bug will emit a very strong, unpleasant odor. They are swarmers and can be quite a nuisance when great numbers of them congregate on walls, walkways, or even indoors. Boxelder bugs will not feed on fabrics or furniture, but can cause stains with their excrement. They may find houseplants appetizing if they get inside, and have been known to bite.

Boxelder bugs are most common in areas where there are lots of boxelder trees (Acer negundo) growing. In the spring the females lay their eggs in the bark of boxelder trees (or maples, ash, or fruit trees) the young will feed on stems foliage and seeds during the growing season, and then the adults will congregate on dry, protected locations looking for overwintering sites.

To control boxelder bugs indoors, the best method is to vacuum them up and then discard the bag. Make sure window screens, frames and cracks and crevices are well sealed to prevent entry. Outdoors, boxelder bugs can be sprayed with insecticides labeled for control. Your local garden will have recommendations.

Thanks for your reply, Cindy. I thought at first they were boxelder bugs, but then realized I don't have any boxelder trees! Then I saw a picture of the milkweed bug and googled milkweed and clematis and saw they were related.

A curious thing I noticed, the one day this past week that it was cloudy and cold, the bugs were gone! The next day they were back.