365 Urban Species. #019: Cellar Spider

[urbpan]

Urban species #019: Cellar spider Pholcus phalangioides

These spiders are almost always found indoors, almost always in cellars (though these photos were taken in a cellar-like bathroom). Perhaps this begs the question: Where were they found before the invention of cellars was introduced to North America? Brief, haphazard research has not revealed a definitive answer, but one can imagine that they must have originally inhabited caves, and perhaps large hollow trees. Thinking about it for a moment, the development of buildings with cellars (nearly all buildings in the northeast have them) must have meant an explosion in the population of cellar spiders. Few animals have benefitted so much from the spread of humans into their territory.

Cellar spiders hang upside down in their tangled cobwebs waiting to prey on insects or other spiders. They are unusual among spiders in that males and females live near one another. Reportedly their venom is powerful, but their fangs are incapable of penetrating human skin. Like nearly all spiders, they are harmless to humans, and helpful consumers of insect pests. (In a nasty kind of irony, the two dangerous kinds of North American spiders--the black widow and the brown recluse--are also urban species that prefer to live near humans.)

Comments

[agelena.livejournal.com]

Personally, I think the spider pictures should be Out There in all their Spidery, Eight-Legged Glory.

[urbpan.livejournal.com]

Your opinion, while welcome, is not surprising. :)

[agelena.livejournal.com]

I'm that predictable?

[urbpan.livejournal.com]

Somewhere between the spider icon and the spider username...

[iheartoothecae.livejournal.com]

Yep. Mo' spida, mo' bedda.

[badnoodles.livejournal.com]

Might be worth pointing out that this is a true spider, unlike a Harvestman/Daddy Long-legs, which is not.

Cellar spiders are also frequently mis-identificed as Brown Recluse spiders, due to people panicking at the pattern on the Cellar Spider's abdomen. The true recluse has a *distinctly* violin shaped marking on the abdomen and six eyes grouped in pairs across the front of the head, like so: .. .. ..

[urbpan.livejournal.com]

Might be worth pointing out that this is a true spider, unlike a Harvestman/Daddy Long-legs, which is not.

...which you have now done, thank you. (I avoided mentioning that daddy long-legs is the common name for three distinctly different animals here, as I've brought it up before, and for space reasons.)

Do you know enough about these species to verify for me that the above pictures are of a female and then a male?

D'ja get my package?

[badnoodles.livejournal.com]

I can't tell from those pictures - the male should have a copulatory organ on the last segment of his pedipalps, and the female should have an epigynum near her spinnerets, and if she's laid eggs, she should carry the egg sac in her chelicerae.

And yes, I got your package yesterday. I'll be baking this weekend. :)

[bunrab.livejournal.com]

Well, and the recluse has more typical spider legs, not the long ones on this spider.

[(Anonymous)]

And I agree - keep the spiders out in the open!

[drocera.livejournal.com]

The above message was from me.

[zipotle.livejournal.com]

I'm shuddering but I tolerate these in the house. I know they catch the freaky creepy things that I REALLY don't like.

[bunrab.livejournal.com]

Spiders are our friends, along with bats!
When we lived in Austin, I used to enjoy watching wolf spiders - one had a good territory staked out in our bathroom right near the toilet, and I could watch him for quite a while, pouncing on small things.

[momomom.livejournal.com]

desensitize those spider phobes ... lose the cut

[wirrrn.livejournal.com]

Hey,

Cellar Spiders venom is actually very weak. The "deadly but non-penetrating fangs" schtick is an Urban Legend.

'Daddy Long Legs' are also confused over here with the *true* Daddy-Long Legs, a Harvestman, and another Daddy Long Legs which isn't even an arachnid but a type of Crane Fly!!

[(Anonymous)]

I love these things-they literally can kill ANY insect or bug that enters your home even though they look harmless and intimidating.

One large critter that was above my bed (my eight-legged pest guardian)managed to take out a huge house spider a couple of pesky woodlouse spiders as well as a moth and some smaller flies.

They are great to have around the house-if you don't like bugs then at least let this one roam-they don't look scary and are very beneficial.

[(Anonymous)]

Are you sure they can't bite humans? I had a spider bite (a pretty nasty one) one afternoon in my apartment in SF and I found a spider (though it only had six legs) that looked really similar to a cellar spider with the same striped knees. I caught it in a clear plastic cup and in the two minutes that it took me to bring the spider outside, it had begun to spin a web in the cup... Two weeks later, I found another one in my room (with only six legs again, so maybe it was the same one or not a spider at all...). I don't know. I'm confused.

[urbpan.livejournal.com]

Spiders very very rarely bite humans--they only do so if they get trapped between clothes and skin. Most "spider bites" are bites from other unseen arthropods, usually biting flies of some kind. Even if a cellar spider had cause to bite you, all the sources I have read say that their fangs are too small and weak to penetrate human skin.