Currently viewing the category: "Running Crab Spiders"
What's That Bug? does not endorse extermination

Subject: Spider in Hydrangea
Location: Texas
May 14, 2016 9:06 pm
What kind of spider is this? is it venomous or harmful?
Signature: Jacob Chapman

Running Crab Spider, we believe

Running Crab Spider, we believe

Dear Jacob,
We believe this is a Running Crab Spider in the family Philodromidae, and possibly in the genus
Philodromus which is well represented on BugGuide.  According to BugGuide, the family members can be recognized because they:  “tend to have the second pair of legs significantly longer than the first pair, which distinguishes them from the similar Thomisid crab spiders. In addition, thomisids have third and fourth legs that are shorter and more slender than the first two pairs of legs, while philodromid legs are subequal in length.”  While Running Crab Spiders do have venom that they use to incapacitate prey, they are not considered dangerous to humans.  The long first appendages, known as pedipalps, indicate your individual is a male.

What's That Bug? does not endorse extermination

Subject: ID: Happy face Ebo species?
Location: San Mateo County, CA
April 15, 2015 4:54 pm
I’m wondering if you might be able to identify this Ebo to species – I found it a few days ago in San Mateo, California. There are very few Ebo photos online and barely any keys, but there are only eight species to choose from in North America. I am not an expert, just the finder/photographer, but I’d love to know if possible.
Here’s the photo link on BugGuide: And my original post of this spider on iNaturalist, which includes better geodata and an alternate/enhanced photo:
Thank you so much for doing this – !
Signature: – Robin Agarwal

Running Crab Spider

Running Crab Spider

Hi Robin,
Now that the contributors of BugGuide have determined that your image is a Running Crab Spider in the genus
Ebo, you may get additional assistance there as well as on our site.  We are posting your image and we hope our readership can contribute to your request.

Hi Daniel,
As of yesterday, it was identified as Ebo evansae by Darrell Ubick, Arachnologist at the Cal Academy of Science.
Thanks for your help on this!
– Robin

Thanks for letting us know Robin.  We are updating our posting.

What's That Bug? does not endorse extermination

Subject: brown spider IN MY TOILET PAPER ROLL.
Location: Western PA
March 27, 2013 12:13 pm
Ok. So this brown nightmare spider fell out of the toilet paper roll this morning, probably because mother nature wants me dead. Can you identify this spider before I do something rash, like call a priest, or perhaps burn the house down? It was brown – it looks darker in the picture because I put it on Instagram (as proof that my house is out to kill me, and to explain to my friends and family why the next time they use my bathroom there will be a bidet in place of toilet paper). Also of note, while there SHOULD NOT be Brown Recluse in our area, there are. My son was bitten in 2009, my neighbor was bitten within days of my son, and my cousin was bitten in May 2012. Please help!
Signature: Cassie

Deadly Bathroom Spider

Deadly Robotic Bathroom Spider

Dear Cassie,
We have just learned about an elaborate terrorist plot that involves robotic spiders that hide in bathrooms among the toilet paper.  When the toilet paper is used and the spider comes into contact with areas of tender flesh, it bites the hapless human and injects a mind control substance much like the zombie venom the Emerald Cockroach Wasp uses on Cockroaches.  The human then does the bidding of the terrorist cell which uses the radio receiver in the robotic spider to set into motion a plan that involves the placing of additional robotic spiders in the homes of friends and relatives.  This will create a veriable army of zombies expected to bring about the downfall of the capitalist and consumer culture we have enjoyed for many years.  It seems western Pennsylvania is ground zero for the attack.  Consider yourself lucky to have avoided this evil plot to take over the world, at least for now.

Update:  April Fools
Eric Eaton provides and ID
The spider in the image is an adult male running crab spider in the family Philodromidae, probably genus Philodromus though I’d need to examine the specimen to be absolutely positive.
Are you sure you want to potentially start another viral spider hoax?  The arachnological community battles enough of those already.  Just sayin’.

Ed. Note:  April Fools’ Day Joke
While the original letter is true and unadulterated, we found it so amusing we thought we would have a bit of fun with the response.  We did clue Cassie in on our intentions to run this as a prank on our readership and we sincerely hope we haven’t offended anyone.

Here is our original response to Cassie:  “Hi Cassie,  We are working on getting your spider identified, but we got such a chuckle out of your letter that we are planning it to be our April Fools’ Day joke.  We hope to get back to you really soon with an accurate ID as well as a hoax response.”  For the record, male spiders are not considered dangerous and Running Crab Spiders are considered harmless.

hahaha!! thank you! 😀 that’s awesome!
you guys rock!

What's That Bug? does not endorse extermination

Subject: I can’t find this guy in any books!
Location: Wichita, KS
October 17, 2012 6:34 pm
Dear Bugman,
Originally I thought this was a crab spider but it doesn’t match any of the pictures I’ve seen. Also, it lays incredibly flat when resting and appears to have feathery, white hairs on it’s back legs. I’m stumped! Thanks for your help!
Signature: Matt

Running Crab Spider or Flattie???

Hi Matt,
Looking at your photos and reading your description, we believe this is a Flattie in the genus Selenops.  See this photo on BugGuide which reports the genus from Texas, Arizona and Florida and notes:  “This genus is found throughout the tropics and subtropics worldwide and can be found in southern parts of the U.S.”
  Since Wichita is in southern Kansas, this is a possibility.  We cannot see any examples on BugGuide with the hairy legs, but this Australian relative on the Brisbane Insect website looks very similar to your spider.  We wish we could make out the eye pattern on your spider.  We would love to substantiate our identification with others.

Running Crab Spider or Flattie???

Correction Courtesy of Eric Eaton:  Running Crab Spider
I believe this is actually a specimen of a Philodromus sp. (“running crab spider,” family Philodromidae).  I think flatties are restricted to the southern U.S. and the tropics.

I appreciate all of the information! I’m not an expert but after reviewing both pictures, I think it resembles a Flattie more. The biggest difference appears to be size and the coloration on the abdomen. Also, the feathery appendages are different than what I’ve seen online as well. I need to get a better series if pictures and perhaps use a macro lens to photograph the eyes.
Certified Coloring Book Professional

Thanks for the update Matt.  We would tend to trust Eric Eaton’s opinion, but the photos you submitted are lacking in detail.  A good photograph of the eye arrangement would be helpful.  After Daniel’s book came out, he had a wild idea to do a children’s coloring book.  What do you think?


What's That Bug? does not endorse extermination

anatus formicinus eating unidentified caterpillar
Location: Toledo, OH
March 21, 2012 11:13 am
Afternoon, Bugman.
Ran in to this guy while chasing snakes (to photograph, not to harm) and didn’t have the heart to lift the wood he was on to follow my snake friend. Pretty sure it is anatus formicinus, but after half an hour of digging around I can not identify my caterpillar. Ah well, it was still a wonderful sight!
Signature: Katy

Running Crab Spider eats Caterpillar

Hi Katy,
We believe you have correctly identified this Running Crab Spider, though we are correcting the spelling of the genus name which is
Thanatus.  There are some photos of Thanatus formicinus on BugGuide that look very similar.  We believe the caterpillar is most likely a Cutworm or Noctuid Caterpillar, or possibly a relative of the Tent Caterpillars, but we haven’t the time this morning to do that research.  This is a thrilling spring Food Chain image.

What's That Bug? does not endorse extermination

Green spider captured
Wed, Jul 8, 2009 at 2:16 PM
I captured this spider at my wife’s request, it was sitting inside the carport.
Haven’t seen a green one before but have seen brown ones.
Kearns, utah

Nursery Web Spider???

probably Running Crab Spider

Hi Steve,
We believe this is a Nursery Web Spider in the family Pisauridae, which includes the Fishing Spiders. These are large spiders and your photo does not indicate scale, nor does your letter provide any indication of the size. We are uncertain of the exact identification, but we do believe the family is correct. Perhaps one of our readers will be able to provide more specific information.

Update from Eric Eaton
Hard to tell, especially without a size being given, but I would suspect this is actually a running crab spider in the genus Tibellus, family Philodromidae.  A close-up of the eye arrangement would also be telling…..


What's That Bug? does not endorse extermination