Cobweb Spider
Jeremiah insists that he is a terrible arachnophobe, yet he continues to send in great spider photos. I don’t know if you’re actually a terrible arachnophobe, Jeremiah, but it is indeed clear that you are quite bad at it. As a former expert arachnophobe, I remind you that the point of arachnophobia is to stay as far away as possible from all spiders. (As a recovering arachnophobe, however, your efforts are commendable. Keep it up!)
Jer says this spider is about 4mm long, which puts it in the same weight class and armaments classification as my beloved Steatodae, though this is not a member of that genus. The abdomen is taller than it is wide, which is a hallmark of Family Theridiidae, the cobweb spiders. Yes, that means this spider is a (distant) cousin to black widow spiders, but that doesn’t mean you should be afraid of it. Quite the opposite, in fact: this spider occupies the same ecological niche as black widows. Remember, kids: a thriving colony of harmless spiders is the best way to prevent harmful spiders from gaining a toehold.
About names: the suffix -idae is now generally used to indicate Family level in the taxa, and theridi is Greek for “small animal”. So it is that Theridiidae loosely translates to “Family of Wee Beasties”, which I think is kind of sweet. The Family is not monophyletic, which is a fancy-schmancy word that means “all evolved from a common ancestor”. A lot of the taxonomic tree was populated before we had the ability to study genetics, and so Theridiidae consists of the descendants of different ancestor spiders, who adapted to similar environments in similar ways. And so the name, albeit accidentally, fits quite nicely: what these critters have in common is that they are all wee beasties.
This spider is from Delaware, USA, and since this photo was taken last week it is is active indoors during the winter. Can anyone get us closer to a proper ID?
Slowly getting the site back onto an even keel. It's nice to get back into the old posting rhythm.
JFargo said,
March 21, 2008 @ 11:32 am
2 quick points:
~While it’s technically Winter, the weather has been above freezing for the most part, and Spring-like.
~It was in the doorway to my workroom, which is outside, so while it may have had some indoor heat leaking out, it was outside, making its existence that much more strange.
Okay, one last point:
~With camera in hand, I have no problem approaching scary things, because it’s “For the photo!” Without a camera, I’m having problems getting into that room as it’s currently flanked by two of the wee beasties!
tceisele said,
March 21, 2008 @ 12:29 pm
“Can anyone get us closer to a proper ID?”
Probably not, at least not from a photo. I just got a copy of Spiders of North America - An Identification Guide, and while it is fascinating and detailed, it does make it abundantly clear that identifying spiders to below the family level from a photograph is a mug’s game. Most of the features that even identify spiders down to the genus are things like the exact shape of the male pedipalps, or the structure of the female gonopore, and neither of those show up very well on the average photograph.
And this book, which was essentially written by experts for use by other experts, pretty much admits that most of the time you just can’t make a species identification, so they just didn’t try (it only classifies spiders down to the genus level).
tceisele said,
March 21, 2008 @ 12:45 pm
Of course, having said that, if somebody wanted to tell me it was an American House Spider, Achaearanea tepidariorum, I wouldn’t argue the point.
JFargo said,
March 21, 2008 @ 1:56 pm
Of course, the story David doesn’t tell is about the email he sent back, starting with something along the lines of “GET OUT OF THE HOUSE AND CALL AN EXTERMINATOR RIGHT AWAY!
just kidding.”
I’ll tell you, my heart stopped beating for just a moment. My brain went “Kill it with fire!” and my eyes widened to the size of kettle drums.
Thankfully I kept reading before I ran out of the house screaming.
Earl said,
March 22, 2008 @ 9:50 pm
I think a shot of it’s gonopore is order. It will ensure a proper I.D. and it will help you overcome your arachnophobia completely! Remember if it bites you, it was all for science. Good luck Miah!
JFargo said,
March 23, 2008 @ 3:59 pm
I have no idea what a gonopore is. Why don’t you come back up to DE from TX and point it out? You can even take the picture, if you want!
If it bites me, and I die from it, I’m blaming you, Earl.
Insect Picture of the Day » Golden Orb Weaver said,
July 25, 2008 @ 7:00 am
[...] afraid of spiders. Anyone who has seen my comments on Spider Friday knows this is true. The smallest little eight-legged beast can send me skittering across the room in fear, except for when I have a camera in hand. The [...]
tceisele said,
August 30, 2008 @ 5:55 am
You know, sometimes I think the taxonomists are just jerking us around. When I linked to the entry for the American House Spider in a comment above, I swear that Bug Guide gave the genus name as Achaearanea. But now, if you follow the link, they give it as Parasteatoda. No explanation, no note that it used to be different, just “hey, let’s do a quick name change, nobody will notice!” We have always been at war with Eastasia.