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Photo#462640
L. mactans? - ventral - Latrodectus hesperus - female

L. mactans? - ventral - Latrodectus hesperus - Female
McKinney Roughs Nature Park, Bastrop County, Texas, USA
September 16, 2010
Size: 10mm
Can we say for sure that this is Latrodectus mactans? I'm going on the hourglass being more anvil-like than hour-glass-like. In addition, the Field Guide to the Spiders and Scoripions of Texas reports that the adult female L. mactans sometimes has multiple spots dorsally. She has produced egg sacs for me, so she's definitely an adult.

Images of this individual: tag all
L. mactans? - ventral - Latrodectus hesperus - female L. mactans? - dorsal - Latrodectus hesperus - female L. mactans? - posterior - Latrodectus hesperus - female L. mactans? - portrait - Latrodectus hesperus - female L. mactans? - hourglass - Latrodectus hesperus - female L. mactans? - sling - dorsal - Latrodectus hesperus - female L. mactans? - sling - ventral - Latrodectus hesperus - female

Moved
Moved from Widow Spiders.

 
I'm unable to confirm this mo
I'm unable to confirm this move for myself. I wish we had a definitive way for any party to ID these spiders. I'll hold off on ID'ing her until I raise an adult male offspring.

 
Agreed L. hesperus
I now have an adult male offspring of this female, and can confirm that she was indeed L. hesperus, as already determined. The adult male looks almost identical to the 2nd instars I photographed.

 
Glad
you were able to confirm for yourself, but just keep in mind everything your images show indicate hesperus based on the morphology of the species. Our NA spp. of Latrodectus are often as easy to ID from photos as the NA Argiope spp. are.

 
Easy for whom?
Clearly, I was unable to identify the species from the resources on BugGuide and those to which people directed me. There was some question among those in this discussion until I took pictures of the immatures. If it was easy for you then maybe you could put in the effort necessary to make it easy for others.

If BugGuide wants to be a reliable resource, it's going to need to clearly distinguish specimens ID'd by visual comparison from specimens ID'd by means generally accepted among taxonomists. Only once we have a clearly defined pool of conventionally identified specimens can we start drawing conclusions about visual characters not formally documented. Absent that identification is by people who have learned the hard way, for themselves, or by unverifiable community magic.

New spiderling shots
One of her egg sacs hatched this morning, and I've added photos of two of the spiderlings. Does this get us anywhere? Thanks!

widowman, your web site looks fantastic, but I wish you'd fix picture embedding. The only picture I see is the one of you holding a widow at the top, and that's only because google is hosting that image. I guarantee that *you* are only person who can see the embedded photobucket images, probably because you have a photobucket account, or because your browser is logged into photobucket. I've check on four different browsers, two different computers and a cell phone, over two different internet networks. Nada.

Maybe someone else can confirm for him, so he doesn't think it's just me? Try this hesperus page.

 
i'll try to fix it
the spiderlings look very much like hesperus to me. thanks very much for posting those! helped a lot.

that's really weird. i haven't worked too much with hosting photos before, what would you suggest? can i host them somewhere else that would make it work? i do need to update some pics anyway so that would be good.

 
The males are pretty distinct
The males are pretty distinctive, aren't they? Maybe I just need to raise a male to find out with certainty. I suppose I could eventually sacrifice her too.

 
I played with it a little. I
I played with it a little. I was able to copy the hesperus page exactly and put it up on the web and have all the images display just fine. That means the problem is google-sites specific. I then logged into a google sites account I have access to and posted a photo to one of your photobucket images, and that worked just fine too. I have no clue why it's not working on just your site. If you want to keep troubleshooting with me, you might email arachnojoe@gmail.com, so we're not cluttering this page.

hey---
you said you got eggsacs, what were the slings like???

that might help a little too

 
What's a sling?
What is a sling? I have two egg sacs, but I've removed them from the web.

 
sorry
spiderling. the slings are sometimes a good way to tell the species apart.

 
Spiderling?! That's funny.
Spiderling?! That's funny. I'll get photos when they hatch. Do we have photos of the slings of widows of known ID? It would be good to post those to the Info page if we do. Also, any pointers on raising young widows? I did it once before, but I let them hash it out until they were large enough to track, with very few left alive, before finally separating them.

I spent most of my life doing butterflies, not spiders, and some butterflies, such as swallowtails, make slings for their chrysalids. That may have thrown me.

 
check this out
http://sites.google.com/site/widowman10/widows/comparison-of-the-north-american-widow-species

there is some info about slings about a page-width down from the top.

 
Dude, what an awesome page!
Dude, what an awesome page! Except not a single image is loading in either Chrome or Safari - I get broken image symbols.

 
interesting! they load fine i
interesting! they load fine in firefox and IE.

 
You might email me directly a
You might email me directly at arachnojoe@gmail.com so we're not cluttering up this page.

 
Not working on Firefox either
Not working on Firefox either. I'm using a Mac. However, another friend of mine is using Google Sites, and I just checked that I can see all of her images.

I just looked at the source. You're pulling from photobucket. I can copy an image URL from the source and load it directly that way, but for some reason it's not taking embedded image loads. Do you know that they load embedded at IP addresses other than yours? What happens if you log out of photobucket and try it?

 
haha i have no idea :) i n
haha i have no idea :)

i never really bothered taking pictures of any of my slings because i had the descriptions there. in hindsight, that was probably a bad idea! maybe next season...

Moved
Moved from ID Request.

that would be my guess
looks like it to me

 
This
is actually L. hesperus.

It is typical of adult female hesperus in the southeastern area of their range in the US (AZ, NM, TX, etc) into Mexico to be heavily marked, and they were once described as L. mactans texanus.

 
ah, so this is the one huh? i
ah, so this is the one huh? i guess i was looking at the shape of the glass in the up close shot. i know the dorsal spots more resemble hesperus though...

 
Yes
they are the nicest looking hesperus.
Of course I love any adult female widow that retains the juvenile markings... I think it's nicer than just plain black.

 
Reference?
Thanks Jeff. Can you give me a reference so I can confirm this myself? I'm doing a survey for a park and want to be certain. Thanks!

 
See
Kaston, 1970 - Comparative Biology of Black Widows.

Great images of the spiderlings!

 
Oh, I just noticed this post.
Oh, I just noticed this post. I can't locate this thing on the net. SONA doesn't list this document as being definitive for the species; most of the works cited post-date Kaston's, so I wonder how his findings would hold up. I really think we need a male palp.

 
Sure
no problem, but it is hesperus.

The Kaston paper is still one of the definitive works on our three NA black species, and still referenced in many current publications. The fact that a publication isn't listed in SNA is meaningless.

Also, there is no mistaking the spiderlings. Coloration and pattern are unique to hesperus.