csl57's picture

Steatoda grossa / nobilis?

Observed: 11th March 2007 By: csl57csl57’s reputation in Invertebrates
IMG_7953
Description:

Took this photo several years ago, before false widows were headline news! I noticed this spider on account of its glossy, dark legs and thorax.
With all the recent excitement about the Steatoda spiders I thought I'd dig out the photo. Initially I was sure it was S. noblis. However, when I looked on Wikipedia this is a dead ringer for what they have as Steatoda grossa. I think they are wrong but thought I'd get a second opinion. Also, I'm currently working on a website dedicated to these critters: False widow spiders and am interested in sightings and anything else Steatoda related.

Identifications
Species interactions

No interactions present.

Comments

Jonathan's picture

Interesting website. You

Interesting website. You might want to include this link to the iSpot species page for S. nobilis http://www.ispotnature.org/species_dictionary/Steatoda%20nobilis

Please correct the spelling to Steatoda nobilis (not noblis). Why not use the 'Get recommended' button and that will ensure that the spelling is right and matches the UK species dictionary. Then your observation can be displayed with all the others of the same species.

Jonathan
University of Edinburgh and Biodiversity Observatory (OU)

csl57's picture

Hi Jonathan, Website is still

Hi Jonathan,

Website is still a work in progress but should be complete soon. Apologies about the spelling - should get that right if I'm building a website about them!

So, do you agree it is S. nobilis. As I mentioned it is very similar to the image of S. grossa on Wikipedia - http://en.wikipedia.org/wiki/Steatoda_grossa

The Cornwall Guide - www.cornwalls.co.uk

mattprince1969's picture

Nice website.. could do with some pictures of confusion sp.

So far the number one false false widow is poor old zygiella x-notata, with nuctenea umbratica and metellina sp in shared second place. Quite why people think araneus or tegenaria look like falsies I don't really understand...

As for the s.nobilis vs s.grossa, nobilis if well marked looks like a white ink blot test, grossa looks like a set of regular fat chevrons decreasing in size towards the rear end. There is much individual variation including all black (mostly female s.grossa) but the general pattern is usually present for both. A very narrow front mark and thin markings reaching the band around the abdomen = s.nobilis as in your case. Broader chevrons which don't reach the band = s.grossa. Simples ;)