Subject: Red Beetle with Black Spots
Location: Johnson County Kansas
July 9, 2012 7:57 pm
I found the attached in Johnson County Kansas. The beetle was sitting on milkweed and although there was evidence of damage adjacent to the beetle I did not observe it feeding. The brown caterpillar in the attached photo was one of several that were indeed feeding on Milkweeds in my pasture.
Signature: Mike

Milkweed Longhorn Beetle

Hi Mike,
Normally we like to confine the number of insects in a single posting to one unless they are the same family, but we are making an exception in your case because we have a Milkweed Meadow tag because so many different insects comprise the intricate ecosystem that depends upon milkweed.  Your beetle is a Milkweed Longhorn in the genus
Tetraopes.  If they are disturbed, they create a squeaking sound by Stridulation.  The sound is produced by rubbing body parts together.  The caterpillar was a bit more of a challenge.  We quickly located this Gaia Garden:  The Milkweed Insect Tribe webpage with a photograph identified as the orange-margined dogbane moth, Cycnia tenera.  We always double check identifications if possible, and that name on BugGuide was a different insect.  As luck would have it, additional searching led us to another member of the same genus, Cycnia inopinatus, the Unexpected Cycnia Caterpillar, also on BugGuide.  Many insects that feed on milkweed sport orange or red and black coloration to warn predators that the insects are either poisonous or distasteful due to the toxins in the milkweed.

Unexpected Cycnia Caterpillar

Daniel, thank you very much for the information. FYI I have about 2 acres of Milkweed (many varieties)  in my pasture that is home to a wide variety of insects. This year for the first time I have yet to find any Monarch Butterfly caterpillars in them. Again, thanks for helping out a true neophyte with some good information. _Mike Lewis_

We are very disturbed to learn that two acres of milkweed did not produce any Monarch Caterpillars despite having been a habitat for them in the past.  We wonder if this is a local drop in population or if this is more global.  That is sad news. Perhaps if you happen to see any in the future, you can take some photos and send them to us with the subject line Monarch Caterpillars.

I will be happy to sned you any new photos I get of Monarch Caterpillars. I am not an entomologist nor a botanist but from my layman’s perspective it is most likely a combination of factors that has reduced the population of large Butterflies on my small farm.
A severe drought has increased the local farmers desire to produce additional forage for their livestock. Fields and field edges that used to produce large amounts of nectar producing plants like Ironweed and Red Clover have been treated with herbicide to make way for livestock friendly plants like orchard grass.
The flowering trees in my yard like apple and dogwood produced almost zero flowers this year. I typically plant a patch of approximately 200 square feet of Dill for the Black Swallowtails. I got almost no germination of my dill seeds this year. Even the bee hives I keep on my place have reduced their honey production this year by at least 40% over past years.
Hopefully this is not a complete catastrophe and in time some of my gossamer winged friends will return.

Thank you for that very thorough analysis Mike.


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Location: Kansas

One Response to Milkweed Longhorn Beetle and Unexpected Cycnia Caterpillar

  1. Frederick Nunley says:

    Found the same beetle in my garden on the swamp milkweed mating the other day. Got some good photos with my iPhone camera posted to Instagram .. I came hunting to find out what the beetles name was as I haven’t seen this really red one before. I caught them matting then one took wing and flew away! No Monarch butterflies seen here in Washington, DC yet this summer as of June 21st 2015. Hoping they will appear soon. We are trying to keep our various asclepius growing in our flower gardens.

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