365 Urban species. #323: Devil's Coach Horse

[urbpan]

Photo by cottonmanifesto. Location: Olmsted Park.

Urban species #323: Devil's coach horse Staphylinus olens

First, I must confess to another tentative and perhaps dubious identification. In my defense, there are more named species of insects than any other life form, more species of beetles than any other insect, and in North America, more species of rove beetles than any other beetle family. That being said, this creature looks very much to me like a devil's coach horse, a European rove beetle widely introduced to gardens and yards around the world.

You might think that underneath a log is nice safe place for detritus-feeding animals, peacefully grazing on rot-softened organic matter. But the maggots, earthworms, and woodlice are preyed upon by the devil's coach horse. With powerful mandibles that can deliver a painful bite to a human finger, they chop up their invertebrate prey into chunks. The devil's coach horse is among the largest of the rove beetles, and even feed on other predatory animals, such as the woodlouse spider.

Rove beetles are distinguished by their very short wings, which make them look rather un-beetlelike. Rove beetles' incomplete wing covers (called "elytra") don't cover their abdomens, causing them to be sometimes confused with earwigs. Devil's coach horse beetles bend their abdomens when disturbed, much as earwigs do, but they also emit a foul-smelling fluid. This behavior has earned them the alternate common name "cocktail." I think "devil's coach horse" sounds cooler.

Comments

[spocks-girl.livejournal.com]

In all my childhood years of rooting around in the muck, I've never seen one of these creatures before. Thanks for the profile.

>>I think "devil's coach horse" sounds cooler<<

Absolutely!

[drocera.livejournal.com]

Ha! My dyslexic mind read that as "Devil's cockroach." Just as good as coach horse, in my opinion!

[wirrrn.livejournal.com]

Hey,

That's definitely a Devil's Coach Horse. Like all of the Staphylinids, they're a primary predator of maggots, which means they're found in large numbers on human corpses at the scenes of homicides. I'm prolly going to be up to my elbows in them when I start my Forensic Entomology course in February!

The most common Devil's Coach Horse over here is this one, The Orange-Headed Rove Beetle:
http://agspsrv34.agric.wa.gov.au/ento/_fpclass/forensic7.jpg

-I've raised several generations of the little dudes in a terrarium with MacNuggets as a food base/maggot attractant!

[urbpan.livejournal.com]

Thanks so much! Usually I run unsure I.D.s past my panel of scientists (you and the other lj friends) but I decided to take a chance with this one.

[wirrrn.livejournal.com]

Rove Beetles are pretty distinctive. Kind of like harder, pincer-less earwigs!!

[ankhanu.livejournal.com]

Careful in the qualifiers; staphylinids cover pretty much all trophic roles, from fungivore to predator. Most are predators, however.

[urbpan.livejournal.com]

Good catch!
Thanks for that.

[urbpan.livejournal.com]

Oh, wait, I thought you were correcting me! :)
Phew.

[wirrrn.livejournal.com]

Hey,

Yeah, I forgot to add the "most" instead of "all". Whoops!

Identification

[rockbalancer.livejournal.com]

So what field guide did you use for this identification. I really would like to see it. I have had a hard time finding an Eastern Mass insect field guide.

Re: Identification

[urbpan.livejournal.com]

Ah, well, in this case I used a variety of online sources. The insect guide I usually consult is the standard old Peterson's guide. I don't know of an insect guide specific to our region.

Devil's Coach Horse

[(Anonymous)]

We just found one in Sequim. Never seen one before!

[(Anonymous)]

i just found one of these in my resturant here in mount vernon wa. does anyone know if they nest or reproduce quickly?

[urbpan.livejournal.com]

Since this is a predatory insect, they are unlikely to be found in large numbers indoors--there would need to be an infestation of prey animals (slow-moving things like caterpillars). As a pest control professional, I would classify this as an "occasional invader" and not be worried about finding a single one.