Swamp Milkweed Leaf Beetle


Swamp Milkweed Leaf Beetle (Labidomera clivicollis), quite a large name for a beetle that is just half an inch in length. These beetles with the long name have a defense tactic for warning potential predators to stay away, Aposematism. It’s unusually bright coloration is used as a way to avoid being attacked or eaten. This the same technique that Monarch Butterflies use to warn probable predators.

And like Monarchs, the Swamp Milkweed Leaf Beetle eats the sticky white sap of Milkweed plants which contains toxic chemicals. Some insects are able to consume this sap without being poisoned. The chemicals remain in their bodies to protect them. The larvae of Swamp Milkweed Leaf Beetle are eaten by Damsel Bugs, Stink Bugs, and Hover Fly Larvae. I guess they don’t care about the danger signal that is conveyed with the coloring.

Host plants of this beetle include its favorite, Swamp Milkweed (Asclepias incarnata), along with Common Milkweed (Asclepias syriaca), Swallow-wort (Cynanchum), and Twinevine (Funastrum). All toxic to most animals which provides the protection that these beetles seek.


4 responses to “Swamp Milkweed Leaf Beetle”

  1. wonderful, anytime you can work the word apostomesisismsmsmemm into the sentence it’s a worthwhile effort. So, now, what’s a Damsel but, is that proboscis thing on them similar to the jabby thing on the assassin bug, sure looks it… reminds me of when I was in school, and they gave us orange juice cups with straws we had to jam through the aluminum foil to get at the semi good fluid inside.

  2. Just found these on my swamp milk weed here in northern Ohio… are they harmful to the plant and do I need to worry about them destroying the plant or momarch catapillars thank you!!

    • Hi Sue,

      First I must apologize for taking so long to get back to you.

      Seems the jury is out on whether Swamp Milkweed Beetles are good or bad. There are those that don’t treasure Common Milkweed and consider it an invasive native. So with this attitude the SMB helps keep the Common Milkweed under control.

      On the other hand there are some that cherish the Milkweed for it’s benefits that it provides to the Monarch Butterfly. That would be me, and it sounds like that would be you as well. If that is the case, first avoid using chemical insecticides which will hard the Monarchs as well. And this from the Internet: How do you get rid of swamp milkweed beetles?
      To get rid of existing bugs, try first spraying them with a gush of water from the garden hose. Brush the bugs aside with a detail brush to get rid of them. Use a spray bottle filled with water and a couple tablespoons of mild dish soap to remove the insects. Soapy water usually does the trick quite nicely.

      And something that is mentioned as a last resort, something that I’ve not resorted to, so I’m not really familiar with it is: insecticidal soap. Hopefully the soapy water does the trick!

      Thanks so very much for reading my posts, and let me know how things turn out with your milkweed and your Monarchs!
      Bren