Rare Sighting: Female Rain Beetle arrives with rain in California

Subject: What’s this beetle?
Location: City limits of Atascadero, California, 93422
December 16, 2014 12:23 am
I have never seen a beetle like this in all my life living in California.
My cat found it on our porch during a rain storm in the early evening today (12/15/14).
It looked about 1 inch x 1.5 inch in size and had a reddish shiny color to it’s back.
It wasn’t “aggressive” but acted rather sluggish when the cat was playing with it. It did not try to fly off.
Can you identify this beetle?
Signature: Maria

Rain Beetle
Female Rain Beetle

Our Automated Response:  Thank you for submitting your identification request.
Please understand that we have a very small staff that does this as a labor of love. We cannot answer all submissions (not by a long shot). But we’ll do the best we can!

I have since identified the beetle in the pictures that I submitted to your website.  It is a female Rain Beetle (Pleocoma).
Thanks for all you do.
Maria Smith

Rain Beetle
Female Rain Beetle

Dear Maria,
We are happy that you identified your Rain Beetle in the family Pleocomidae.  This fascinating family is limited to the western parts of North America and they have a marvelous life cycle.  Your individual is a male.  The females are flightless and they do not leave their burrows, spending their entire lives many feet underground.  Males appear with the rains.

Correction:  Female Rain Beetle
Based on a new comment, we have learned that this is in fact a female Rain Beetle.

Hi Daniel,
Wow!  Thanks so much for letting me know.  I feel even more special now that I witnessed a Female above ground!  Very cool. 🙂  I posted to the Bug Guide site, as you suggested.  Thanks again! 🙂

Hi again Maria,
We apologize for not confirming the sex of this female Rain Beetle when you first submitted the image, but females so rarely leave their burrows, we didn’t look too closely at the image when we posted it just prior to running out of the house to head for work.

4 thoughts on “Rare Sighting: Female Rain Beetle arrives with rain in California”

  1. Maria Smith is correct, this is a female rain beetle. The large size, reddish color and most importantly, the structure of the tarsi and antennae will separate the females from the males. Sometimes the females will leave their burrows and walk around. Female rain beetles are always a great find. Males are much easier to find, generally, as they fly and are attracted to lights. Based on the locality, I strongly suspect this to be the species Pleocoma badia. Please consider posting a photo on BugGuide.net. I’ve been running a rain beetle thread over there and this would be an interesting sighting.

    • Thanks so much for the correction. We will write to Maria and suggest that she post to BugGuide. Meanwhile, feel free to link to our posting.


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