large black bug with brown legs
October 17, 2009
we found this bug last night outside our front door. it has sux legs and two larger feelers on wither side of its body. its body is black and legs are brown. it crawls sideways and very fast. tried catching it but it was too quick for us
Rhiannon
Wickenburg, Arizona
Dear Rhiannon,
Once we turned to BugGuide to substantiate our simple response, that response suddenly became a bit more complicated. We have always referred to this fascinating creature as a Tailless Whipscorpion, but now that we have noticed that BugGuide has taken its identification to the species level, Paraphrynus mexicanus is being commonly called a Tail-less Whip Scorpion, but the order Amblypygi is still being called Tailless Whipscorpions. The species information page on BugGuide states: “Primarily denizens of humid tropics, most North American species are found in Florida and Gulf states, where they occasionally enter houses” but interestingly, all the submissions have been from Arizona. We prefer the non-hyphenated, compound word spelling of Tailless Whipscorpion indicated on the order information page of BugGuide. These are shy, nocturnal, harmless predators that do not have any venom, and despite the frightening appearance, they are perfectly harmless, though foraging cockroaches, if they could contribute to this web page, might disagree. They are capable of rapid, crablike, sideways, scuttling locomotion.
This is actually an arthropod called a false scorpion or a pseudoscorpion. It is not a whip scorpion (tailless or otherwise).
They have the ability to spin webs which are often found under papers and books. They eat the larvae of moths so they are a helpful bug to find in your home. This causes them to also be referred to as “book scorpions”!
We beg to differ, as we do have Pseudoscorpions well represented on our website.
I concur. Pseudoscoprions typically are much smaller over all, or have much longer legs (depending on their habitat). In fact, the largest pseudoscorpion I’ve ever seen, personally, was smaller than my pinky nail.