Shower Spiders

Just when you thought it was safe to take a bath….You throw open the shower curtain and are suddenly confronted with an eight-legged freak. Over the years I have answered many an AllExperts.com question about strange arachnids that people have found in the tub or stall, as well as finding my own specimens now and then.

Recently, I was myself taken aback upon entering the shower and spying a particularly fine specimen of a Philodromus running crab spider on the wall behind my wife. I was startled, which in turn startled her, and we spent the remainder of the time with one eye on the spider. Naturally, Ms. Phyllis Dromus dropped lower and lower, eventually settling by the place where the shower head comes out of the wall.

I know what you are thinking. How can a manly-man like me, equipped with knowledge that allows him to identify most spiders, and who knows this one is not dangerous, still be uneasy? That isn’t what you’re thinking? Why are you laughing? Please, this is a family show. Get your mind out of the gutter.

I think there are simply some places where we don’t expect to find spiders, and where we would prefer not to find them even if we normally appreciate and respect arachnids. No doubt the spiders feel the same way: “Gee, where do I have to go to get away from these monsters?! Uh-oh, it’s getting slippery!”

More recently, while attending the Mothapalooza event in Ohio, I prepared to step into the shower after a hot, sweaty field trip. Apparently, the tub had not seen much activity recently because there guarding the drain was a mature male Barn Funnel Weaver, Tegenaria domestica. I managed to snap one shot before trying to coax him into better viewing. That only drove him down the drain and though I was patient he never re-emerged.

I still wanted to wash off before dinner, so I ran a light stream of water out of the faucet. Sure enough, Mr. Barn Funnel Weaver shot out of the drain with lightning speed. He was at the other end of the tub before I blinked. A few more pictures and then I corralled him in a plastic container to show off to folks later. Now, now, no jokes about which of us is better endowed. What are you, twelve?

It is always a little easier for me to address someone else’s spider-in-the-shower experience than it is to chronicle my own, and I’m sure there will be plenty more such episodes crossing my e-mail or AllExperts.com account. I hope I am successful in calming people’s anxiety, allaying their fears, and otherwise turning fright into fascination. I always offer to accompany my female correspondents into the shower the next time, just in case….Funny, no one has ever taken me up on that.

Spider Sunday: Slender Crab Spiders (and their look-a-likes)

Many spiders are “built” to fit their habitat and lifestyle, and perhaps none are better examples than the slender crab spiders of the genus Tibellus, family Philodromidae. They hunt by lying in ambush on grasses or foliage. Their distinctive long body and vertical striped pattern camouflage them almost perfectly. They are not alone, however, as several other spiders share similar coloration and it is easy to confuse them all.

Pictured above is a Tibellus I found in North Cheyenne Cañon, Colorado Springs, Colorado, earlier this week. Had it not been on a green leaf, I probably would have overlooked it easily. Note that this is not a particularly large spider. There are seven species of Tibellus in North America north of Mexico, and adult females collectively range from 6-11 millimeters in body length. Males are slightly smaller, 5-8 millimeters. Pictured below is a juvenile nursery web spider, Pisaurina mira. It will eventually become much larger, as adult females are 12.5 to 16.5 millimeters, males 10.5-15 millimeters. These spiders prowl the same habitats as Tibellus, and adopt a similar resting posture. Pisaurina are more robust in their overall appearance, however, a bit hairier, and have a different eye arrangement.

Another genus that may be confused with slender crab spiders is Thanatus, also in the family Philodromidae. The first two images in my ”Spring Spiders” post are of a specimen of Thanatus. Note the more robust appearance and the difference in the pattern of stripes compared to Tibellus. Both spiders are of similar size, but Thanatus hunts mostly on the ground amid grasses and weeds, whereas Tibellus is almost always found on stems, stalks, grassblades, or leaves.

Lastly, the Striped Lynx Spider, Oxyopes salticus, can sometimes be mistaken for Tibellus. Below is an example I found near Chicago, Illinois. Note the very long spines on the legs, and the more scrunched-up posture as it waits in ambush on a grass stem. Lynx spiders have a longer “face,” too, whereas slender crab spiders have an overall more flattened appearance.

Female slender crab spiders are good mothers. They spin a flattened egg case which they guard religiously until the spiderlings emerge. Here is one I found in Tucson, Arizona. I maneuvered the grassblade several times for better light exposure and she never even flinched.

Do keep an eye out for these amazing grass-mimics. You may find still other spiders, even orb weavers, with nearly identical shapes and patterns in the process of looking for Tibellus. Try using a sweep net if you can’t find one otherwise. You’d be astonished at the diversity of arthropods in a “disturbed habitat” like a vacant lot.

Sources: Balaban, John and Jane, et al. 2004. “Genus Tibellus - Slender Crab Spiders,” BugGuide.net
Kaston, B. J. 1978. How to Know the Spiders (3rd ed.). Dubuque, Iowa: Wm. C. Brown Company Publishers. 272 pp.
Ubick, D., P. Paquin, P. E. Cushing, and V. Roth, eds. 2005. Spiders of North America: an identification manual. American Arachnological Society. 377 pp.

Spider Sunday: Ebo Time

Sorry, in the wake of the popular mania over Tim Tebow, quarterback of the Denver Broncos NFL team, I could not resist the play on words. The spiders of the genus Ebo, members of the “running crab spider” family Philodromidae, are not known for their ability to score touchdowns or inspire a nation. That does not make them any less interesting as a topic of conversation, though.

Philodromids are identified rather easily by the fact that their second pair of legs is longest. The genus Ebo takes this to an extreme, as that second leg is at least twice as long as all the others. Their “wingspan” must be the greatest for their size of any spider in North America. Their body size is small, averaging between two and six millimeters depending on the species, and skewing towards the lower end of that spectrum.

There were 22 recognized species of Ebo found in North America, but some species have recently been reassigned to the genus Titanebo, leaving just seven North American species in Ebo sensu stricto. Their collective distribution is throughout the U.S. and extreme southern Canada. Other species occur in Mexico, Argentina, India, and Russia. They reach their greatest diversity in the southwest U.S., which is where I found the specimen shown in the images below. It was on the edge of the bathtub in my Tucson, Arizona apartment. I guess I cannot say for certain now whether this is an Ebo or Titanebo.

I originally posted these images on Bugguide.net, a bit reluctantly since they also showed a fair amount of lint on the bathtub. Fellow contributor Carol Davis put me immediately at ease with her own comment: “Cleanliness leads to buglessness and then what have you got? No photos!” Fair point, and I replied that I am not a messy housekeeper, I’m promoting biodiversity!

Like most running crab spiders, Ebo prowls for prey among grasses and foliage. At least two species frequent pecan groves in Texas, affording natural pest control to at least a minor degree (Calixto, et al. 2004).

What about the origin of the name, you ask? Well, the German arachnologist Eugen von Keyserling who created the genus gives no indication of its derivation. Ebo was apparently a common name in medieval Germany, a diminutive of “Ebur,” meaning “prince” or “lord.” Hm-m-m, seems that both Ebo and Tebow could qualify for that definition.

Do keep an eye out for these unique spiders, which should be easy to recognize. You could say that Ebo is all elbows.

Sources: Calixto, Alejandro, Allen Dean and Marvin Harris. 2004. Spiders in Pecans. College Station: Texas A & M University.
Kaston, B. J. 1978. How to Know the Spiders 3rd Edition. Dubuque, Iowa: Wm. C. Brown Company Publishers. 272 pp.
Platnick, Norman I. 2012. The World Spider Catalog, Version 12.5
Ubick, D., P. Paquin, P. E. Cushing, and V. Roth (eds.) 2005. Spiders of North America: an identification manual. American Arachnological Society. 377 pp.