Huge Tegenaria sp?

SusieBee · #1 (**permalink**) 03-12-2009, 08:00 PM

Could anyone help with id'ing this spider please. It's Huge!

But it's a lovely spider.

I'ts living under a small water bowl bench very well hidden.

Reading The Seagulls thread I see these can be difficult to id anyway, so I'll go out tomorrow if poss to get pics of palps. I'd like to know if it's male/female? In second image on left there looks like a ball of eggs? Also would like to know if it'll survive winter? Be grateful for any help.

Cheers SusieBee

No.9 Spider · #2 (**permalink**) 03-12-2009, 09:49 PM

A nice healthy female. She should be around for next season anyway. Obviously palp shots would be no good for i.d in this instance, though epigyne shots would help but are hard to achieve on a live specimen.

No.9 Spider

SusieBee · #3 (**permalink**) 03-12-2009, 10:38 PM

Thanks No. 9 Spider, so how can you tell it's a female?

Sorry I'm a newbie to spiders. Is that eggs in 2nd image? Had to google epigyne still

would that then confirm type of Tegenaria she is? Or am I totally wrong in species?

Cheers SusieBee

frits_b · #4 (**permalink**) 04-12-2009, 06:14 AM

Considering the size, this is an adult (or nearly adult) spider. Adult males have swollen palps (the short 'limbs' in front of their head). This one does not, so it must be a female. The epigyne is the female genital, and it's situated on the underside of the abdomen. Taking a closer look at the epigyne will reveal the species; sometimes it's necessary to remove the epigyne from the body to see everything clearly.
The species of Tegenaria may sometimes be determined by examination of the sternum (the underside of the 'head part' of the spider). Quite a few species have a distinctive pattern on the sternum.

SusieBee · #5 (**permalink**) 04-12-2009, 12:10 PM

Thank-you very much Fits_b for all that info

Great stuff.

I could try to get closer pics of the epigyne but obviously won't be removing anything.

I may even be able to get pics of the sternum because she's usually upside down in web, well if I'm lucky and it turns out that she does have distinctive markings. At least now I know what I'm meant to be looking closer at.

Long shot but will be fun trying. Just to add I'm always very careful not to disturb anything around her and give it a few short minutes trying taking pics.
Thanks again for taking time to explain.

Cheers SusieBee

No.9 Spider · #6 (**permalink**) 05-12-2009, 03:50 PM

Sternum shots can narrow down the species in Tegenaria according to some publications but it's not a 100% reliable theory. Even epigynes of Tegenaria under the microscope can prove difficult to i.d. at times.
I've never heard of epigynes being removed from the specimen to aid in i.d., as the epigyne would collapse and be totally unidentifiable. The use of clove oil in which the specimen can be immersed is occasionally utilised (and is necessary for some species) as this clears the epigyne allowing you to see the configuration of the ducts.
The removal of a male palp is sometimes necessary to aid in i.d. as they are sometimes awkward to manouever into the required position when still attached to the spider.
I think she's probably had a number of egg-sacs this year hence the slim abdomen (there are possible egg-sac remnants about, though I'm not convinced the object you refer to is an eggsac, it doesn't look right unless it's one that wasn't viable?).

No.9 Spider

frits_b · #7 (**permalink**) 05-12-2009, 10:16 PM

Quote:

Originally Posted by No.9 Spider

I've never heard of epigynes being removed from the specimen to aid in i.d., as the epigyne would collapse and be totally unidentifiable.

I must admit I never did it myself, but apparently it's a regular practice (at least for certain species) to determine spider specimens. An arachnologist who investigated a Xysticus for me once was also forced to remove the epigyne (turned out to be a bifasciatus).
Just google 'epigyne dissection'.

No.9 Spider · #8 (**permalink**) 05-12-2009, 10:24 PM

Crikey! Just had a look

. Certainly not something I've come across and hope not to, I think I'd give it a miss. Thanks frits_b, for the interesting facts on that. I see that it doesn't come without it's problems as I'd expected.

No.9 Spider

dickybird · #9 (**permalink**) 06-12-2009, 01:46 PM

omg!! the idea of removing any part of a spider just to i.d. it is gross

and not just because of handling the thing!! unless its a completely new species-why would anyone want to dothat?? sorry guys-i dont like spiders but that.....?!

anyway,the reason i came here----what has happened to all my cellar spiders? i have been encouraging them to make their homes around my home as i find all other spiders unbearable to look at. these cellar spiders have disappeared. i noticed them on the move about a week ago but now i cant find one and worse still--the other types of spiders are making an appearance once again. have they gone into hibernation? and if so -where?

db

demicav · #10 (**permalink**) 08-12-2009, 06:17 PM

Quote:

Originally Posted by dickybird

omg!! the idea of removing any part of a spider just to i.d. it is gross

and not just because of handling the thing!! unless its a completely new species-why would anyone want to dothat?? sorry guys-i dont like spiders but that.....?!

anyway,the reason i came here----what has happened to all my cellar spiders? i have been encouraging them to make their homes around my home as i find all other spiders unbearable to look at. these cellar spiders have disappeared. i noticed them on the move about a week ago but now i cant find one and worse still--the other types of spiders are making an appearance once again. have they gone into hibernation? and if so -where?

db

We have lots of cellar spiders but in the colder weather we don't see as many. I think they feast on each other more at this time of the year but they soon make up for it in numbers.