Subject: ground beetles
Location: Anza, California
September 18, 2012 8:38 pm
Thought you might want to put this up on the Bug Love board, sorry it’s not focused better.
Love this site!
Signature: Mary Ann

Sexual Gathering of Acrobat Beetles

Dear Mary Ann,
We are aghast at this photograph.  We cannot imagine what prompted so much sexual activity in such a confined space.  These are not Ground Beetles.  They are Darkling Beetles.  We are nearly certain they are Desert Stink Beetles or Acrobat Beetles in the genus
Eleodes, which you can verify on BugGuide.  They will stand on their heads, stick their rear ends in the air and release a malodorous smell if disturbed, hence the common names.  We will check with Eric Eaton for confirmation on that identification.  Your photo is both an amazing documentation of natural history as well as a humorous amusement.  We are going to feature it on our homepage banner.

Thank you, that explains a lot.  They act like stink beetles, but I’ve never been able elicit an odor from them (I’ve heard if you squash them you can smell them, but I cant’ bring myself to do it).  I have a theory on the sex, the females are eating and are blocked from going forward, and the males seized the opportunity. <gg>  I am very flattered that the photo is on the homepage banner!!

Eric Eaton makes a correction
Hi, Daniel:
Those look to me to be darkling beetles in the genus Coelocnemis rather than Eleodes.  Coelocnemis tends to like dry forest habitats.  Here’s more:
Thanks for sharing.  I suspect the females are gathered at oozing sap and the males are taking advantage 🙂

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Location: California

2 Responses to Orgiastic Darkling Beetles

  1. John says:

    Definitely Coelocnemis, not Eleodes. These look like C. magna based upon the shape and luster.

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