Small spider on Argiope aurantia web.

Moved

Moved from Spiders.

… john and jane balaban, 29 October, 2010 - 7:29pm

Moved

… John F. Carr, 21 October, 2010 - 6:00pm

Texas Argyrodes

So I took Levi's paper from 1962 and listed out all the spiders that were found in TX on this page. Of course that's a long time ago, but if we look at the species in your area it would leave Rhomphaea fictilium, Neospintharus furcatus, Argyrodes elevatus, Faiditus cancellatus and Faiditus subdolus & just to be safe I think we should include Argyrodes pluto and Neospintharus trigonum. Now all we have to do is read the descriptions for all of these. Of course the obvious choice would be a variation of elevatus, so I read that one first. On page 136 of the article it explains that coloration is variable, young females difficult to separate from A. nephilae, but since nephilae isn't in TX we don't have to worry about that. With inreasing maturity there is an increase in pigmentation. It goes on to talk about a female from Alabama having sides partially black with reddish streaks and the rest silvery and another female with abdomen entirely silvery. Two specimens have sides of abdomens obliquely streaked with brown.

I think it is very likely these are all variations of elevatus. I'd have to read all the other species descriptions to be sure though. (I see that fictilium is ruled out based on abdomen shape.)

… Lynette Elliott, 7 October, 2010 - 8:59pm

I'm assuming that you mean all three image sets - perhaps the earlier ones too. It wouldn't surprise me if they all turned out to be elevatus, but it's funny that the orange ones are much more active than the silver with cross or silver with pattern but no cross. And at least some seemed to have rounded abdomen.)

Also I have a Gulf Publishing Field Guide Series "A Field Guide to the Spiders and Scorpions of Texas" 1997 John A. Jackman (TAMU). It is by no means a complete treatment. In fact it includes only one Argyrodes species description, A. trigonum. But that description sounds quite close to these images. He has only one mid-quality plate but it wouldn't rule these out. Also in an appendix he has a checklist (credited to A. Dean at TAMU) for Spiders in Texas that lists twelve Argyrodes species.

I scanned the trigonum description and the species list. The scan is located here.

http://users.htcomp.net/chalkmountain/bugguide/spider.pdf

I will try to look up some of the references he lists.

… Gregg Lee, 8 October, 2010 - 11:26am

Good info

It appears the only one I didn't have on my list was Faiditus davisi, which Levi shows at the very southern tip of Texas. (I've added it now)

I'll read over trigonum in Levi and let you know what I think. We have a comparison image for trigonum here.

… Lynette Elliott, 8 October, 2010 - 11:45am

Trigonum

You all have been doing some awesome work here!
I've just started my thesis work with the subfamily Argyrodes, and specifically N. trigonum.
I don't know exactly which species this spider is, but I do know it doesn't fit with my gestalt idea of what trigonum looks like. While the comparison image you have could be one based on body type, the picture doesn't really do their most common color variation justice. This image is actually a better one, and based of location I can be certain of its linage to ~90% accuracy. http://bugguide.net/node/view/471124

Hope this helps.
I'll be doing some more field work this summer and hopefully coming up with some voucher species, so I'll check back in then.

… Meghan, 29 March, 2011 - 11:16pm

Argyrodes

Hi Meghan. Thank you so much for your comments. We welcome as much help as you have time to provide. I've moved the other images based on your comments, and we're looking forward to having your expert help.

… Lynette Elliott, 30 March, 2011 - 10:55am