Currently viewing the category: "Rain Beetles"
What's That Bug? does not endorse extermination

Subject: What’s this beetle?
Location: City limits of Atascadero, California, 93422
December 16, 2014 12:23 am
Hello,
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?
Thanks!
Signature: Maria

Rain Beetle

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!

Hello,
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

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.

Jenine Plunkett, Andrea Leonard Drummond liked this post
What's That Bug? does not endorse extermination

Beetle
Location: East San Diego County, CA
December 13, 2011 10:54 am
We found this bug on Sunday. He was hitting the windows and the door in the evening hours. We’ve seen these kind of bugs before, but only when it rains. It was damp and raining that day and 47 degrees. We are at an elevation of 4,000 ft., near the border of Mexico and California. We found it dead on a bucket the next morning.
Signature: Mark

Rain Beetle

Dear Mark,
While this is not a rare sighting, it is a somewhat unique sighting.  Your beetle is a Rain Beetle, a member of the family Pleocomidae and the genus
Pleocoma.  This is a small family that is limited to coastal regions of the west coast of North America from Washington to Baja.  This family is not known from any other parts of the world.  There is work needed on the taxonomy of the genus and it would be nearly impossible for us to provide you an exact species identification.  According to BugGuide, there are approximately 30 species identified.  Many species have very limited ranges, due in large part to the morphology of the flightless female.  One can only begin to ponder what conditions once existed that allowed the range expansion and genetic diversity that contributed to the evolution of distinct species where the female of the species is flightless and immobile.  The grubs live underground, often at great depths, feeding on the roots of oaks and conifers according to BugGuide.  You may find this May 18, 2009 Los Angeles Times article interesting.

What's That Bug? does not endorse extermination

Found a bug
Location: Northern Ca foothills near Auburn CA
November 13, 2011 1:58 pm
Hi, I found this bug on my doorstep this morning. It is about 2 inches long. Not sure what kind it is and if I should be concerned about the trees or house. We live in a heavily wooded area, many pines and oaks in the Sierra Nevada foothills near Auburn CA.
Can you tell us what bug this is?
Signature: Duke

Rain Beetle

Hi Duke,
Congratulations on your wonderful sighting.  This is a male Rain Beetle in the family Pleocomidae (see BugGuide), a family with a range that is limited to the west coast of North America.  Rain Beetles are a very unusual family of beetles.  Larvae live underground and feed on the roots of oaks and conifers and they can remain underground for as long as ten years.  Mating activity is triggered by rain.  Only male Rain Beetles have wings, and they will circle the ground until they locate the burrows of a flightless female.  There are many species of Rain Beetles and many have very limited ranges.  An expert is required to distinguish one species from another.  There was an excellent article in the LA Times several years ago on the Rain Beetles. 

What's That Bug? does not endorse extermination

Is this a Rain Beetle?
November 18, 2009
Just found in the pool flailing around on top of the water — it looks like the other Rain Beetle pictures on your site and thought I’d ask if that’s what this is to confirm. One picture is on top of the net I got it out of the pool with. The other is on the ground. We had rain last night and everything is still sort of wet around here today. Thanks!
Elaine
Rural Windsor, California (North of Santa Rosa)

Rain Beetle

Rain Beetle

Dear Elaine,
You are absolutely correct.  We are happy that our website was helpful with your Rain Beetle identification.  This is the second submission of Rain Beetles we are posting from yesterday.

Rain Beetle

Rain Beetle

What's That Bug? does not endorse extermination

rain beetle photos
November 18, 2009
I came to your site to find out what these are. and now i know, thanks! Here’s the photos i was going to use, enjoy!
dr
northern ca. foothills

Rain Beetle

Rain Beetle

Hi dr,
Thanks so much for the Rain Beetle photos.  We also believe the LA Time article we read this past May is once again live on the website.  It is a wonderful account of an encounter with Rain Beetles.  One of the chapters in our book has to do with insects and weather, and we are going to be writing about the Rain Beetles of the California Sierras.  Since we only have twelve days to finish the manuscript, we may write that chapter next.

Rain Beetle

Rain Beetle

What's That Bug? does not endorse extermination

Looks and acts like a “Junebug”, but comes in the Fall around here
November 12, 2009
Two people have told me these bugs, which are large, clumsy and hit the window at night, are “pine beetles” or “pine borers”, which I have a hard time believing. We do live amongst a lot of oaks, cedars, yews, spruce, etc., but these guys act and look like June bugs and will not be around long.
Rhoni Lawrence
Sierra Nevada foothills, N. California, 2400 ft.

Rain Beetle

Rain Beetle

Hi Rhoni,
These are most definitely Rain Beetles in the family Pleocomidae, an unusual group of beetles with fascinating life histories.  Only the males are able to fly, and female Rain Beetles live many feet underground.  Males emerge from the ground after a rain and fly off in search of a mate.  There are many species of Rain Beetles, but their individual ranges are quite limited, and an expert is required to distinguish one species from another.  There are some nice images on BugGuide.  We read an awesome article about Rain Beetles in the LA Times this spring, but alas, the link online indicates that there is scheduled maintenance on the site and we are uncertain when it will be available.  In lieu of not being able to link to the LA Times article, we are linking to a Bay Nature website with some information.

Rain Beetles

Rain Beetles

What's That Bug? does not endorse extermination