# hourglass patterns in N.A. Latrodectus species



## Widowman10 (Apr 1, 2009)

now, before i get started, these are *GENERALIZATIONS* about the patterns found on the north american widow species. these are by no means foolproof, or a good way to identify species- as will be shown at the end. these are merely observations coupled with pictures. they hold true in most instances. i know this information can probably be found elsewhere on the web too. anyway, hopefully this is somewhat informative or even entertaining for those who know much more than me and can provide better information and pictures  




let's start out with my favorite black, Latrodectus hesperus, the western black widow. this species is the posterboy for black widows. jet black all over, no dorsal markings or patterns, and a great looking glass. the glass is fairly symmetrical, though sometimes just a line. the top half of the glass is solid in almost all cases. and many times, the bottom half of the glass is a mirror image. either way, whether it be a perfect glass, or a line, or whatever, the two parts are connected- no gaps. here are a few images to demonstrate:

a good looking, connected glass:






the line/bar:






faded bottom half of glass, still very characteristic of hesperus:







let's now move on to my favorite widow species of all time, Latrodectus bishopi, the red widow. this species is heavily dorsally patterned, with beautiful ringed spots on the back of the abdomen. anyway, glasses are being discussed here! this species has only the top half of the glass, and it is somewhat squished. the bottom half is absent. here is a couple pics to demonstrate:














next up is the characteristic Latrodectus geometricus, the brown widow- found worldwide. this species is different because the glass is orange, not red. it also has a good looking glass that is connected. the top half of the glass is very good, and the bottom half is an exact mirror image, only enlarged a bit. the bottom is just a little bigger than the top, but looks the same. also, the species can be distinguished by the yellow dots surrounding the spinnerets. here's some examples:














moving on, we have Latrodectus mactans, the southern black widow. mactans sometimes have light dorsal patterning, mostly just a solid red dot near the spinnerets. for the glass, again, it is usually connected. the top half of the glass is normal, but the bottom makes it different. the bottom half is typically 'chunky,' or blocklike. it does not look like a triangle, but a block. here is what i mean:

showing the block, or squished:






another, reminds me of the symbol for the university of tennessee:







lastly, we come to Latrodectus variolus, the northern black widow. this species has dorsal markings, much more so than mactans, usually a stripe or series of dots. the glass is separated, different from the other blacks. the top half of the glass is a nice triangle. a good space is between the two pieces, the bottom piece being like a triangle that had the pointy part chopped off. don't know how quite to describe it better. here are a couple of pics:














and just to show that hourglasses CANNOT be used to identify a species 100%, here are a couple of pics:

weird glass, actually from a mactans:






and no glass at all, from a hesperus:









well, i hope somebody learned something from this. again, these are rough generalizations about patterns found on our N.A. species. oh- and all these pics are mine btw. 

and a BIG THANK YOU to a certain member (you know who you are) for providing me with so many widows, you've been so generous to me, i won't forget it :clap:


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## kalvaer (Apr 1, 2009)

Lovely pics, but Holy smoke.. I hope those were dead specimens you were holding.

I think you have just proved to me though, that I am actually no were near over my arachnophobia and I have shivers all my body from just looking.


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## clearlysaid (Apr 1, 2009)

Haha, that's awesome, Brian!  I didn't realize you amassed such a collection of widows!  That brown widow of yours, the one that tricked us at the last meeting, is actually looking more brown now.  I swore it was black.    Nice write-up and great pics, though.  It's super informative/helpful.  :clap: 



kalvaer said:


> Lovely pics, but Holy smoke.. I hope those were dead specimens you were holding.


Hehe, Brian holds them live.  He IS the Widowman, after all.


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## Widowman10 (Apr 1, 2009)

clearlysaid said:


> That brown widow of yours, the one that tricked us at the last meeting, is actually looking more brown now.


actually, it's still completely black  i just didn't take pics of that one (or a lot of the others!).


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## Irks (Apr 1, 2009)

Widowman10 said:


> let's start out with my favorite black, Latrodectus hesperus, the western black widow. this species is the posterboy for black widows. jet black all over, no dorsal markings or patterns, and a great looking glass. the glass is fairly symmetrical, though sometimes just a line. the top half of the glass is solid in almost all cases. and many times, the bottom half of the glass is a mirror image. either way, whether it be a perfect glass, or a line, or whatever, the two parts are connected- no gaps.


I've seen widows here in California that have either orange, green, or yellow "wings" just above the eyes if you're looking at them head on, on the abdomen. Sometimes they're shaped like two boomerang triangles (^ but flatter), one just above the other, and sometimes only parts are there. Yellow is common, orange is less common, and green I've only seen at specific locations. I thought they were hesperus, since I thought that's all we get here... but if you have a better guess, let me know.
Here's an old pic of one with the yellow markings, mostly there, but part of the second "wing" is missing.





This one was collected very close to stinson beach, california.


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## jsloan (Apr 1, 2009)

Nice pictures and presentation.  Have you got any pics of some of the different dorsal markings on _L. variolus_?  I'd be interested in seeing those.  Have you ever seen white-rimmed, roundish circle markings on the dorsal abdomens of any of _variolus_ or _mactans_?

Are you using epigynes and palps to utlimately differentiate between _mactans_, _herperus_ and _variolus_?  I need to find diagrams for these.

Thanks for the post!


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## jsloan (Apr 1, 2009)

Irks said:


> and green I've only seen at specific locations.


Sounds interesting.  Do you have any pictures?


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## Irks (Apr 1, 2009)

I don't have pictures of the green or orange, I'll have to go collect some. Hopefully I can do that soon. I know where they are though, so if I get some free time I'll try to get pics this weekend.


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## Widowman10 (Apr 1, 2009)

jsloan said:


> Nice pictures and presentation.  Have you got any pics of some of the different dorsal markings on _L. variolus_?  I'd be interested in seeing those.  Have you ever seen white-rimmed, roundish circle markings on the dorsal abdomens of any of _variolus_ or _mactans_?
> 
> Are you using epigynes and palps to utlimately differentiate between _mactans_, _herperus_ and _variolus_?  I need to find diagrams for these.
> 
> Thanks for the post!


jsloan, i can get some pics of the dorsal markings on the variolus if you'd like. they vary quite a bit from what i see. 

and yes, there are some patterns (thin white lines) on the abdomens of some mactans, for example:














and no, i don't have any diagrams for differentiating between epigynum structures of the different species. yet.  maybe i'll make that my next research project...


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## Widowman10 (Apr 1, 2009)

irks, again, as i mentioned, patterns and shapes and markings are only clues and general observations. they cannot be used to ID a species with a good degree of certainty. location is _usually_ the best way, but sometimes pockets (or freeloaders) of an outside species can occur. for instance, i received a mactans awhile back that had traveled on the inside of a speaker from the east coast. a little eggsac and some spiderlings later, a population of mactans would have been established in a den of hesperus.

all that to say that if you live in CA and found it there, my guess off location alone would be hesperus. barring of course it was a freeloader from somewhere else.


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## Pacmaster (Apr 2, 2009)

Awesome thread here, thanks widowman!

Ill keep an eye out for anything unusual for ya!


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## buthus (Apr 2, 2009)

Glassic man!  :} 










This one was collected from Rialto/Rancho Cucamonga CA.  Intense light revealed small chunks of the top and bottom of the glass, but all in all it was a glassless widow.


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## jsloan (Apr 2, 2009)

Widowman10 said:


> and yes, there are some patterns (thin white lines) on the abdomens of some mactans, for example:


Yes, that's the pattern I was thinking of.  Thanks.  Where is that particular spider from?


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## davidbarber1 (Apr 2, 2009)

Very interesting and informative. Thanks for the pics and the info.

David


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## Widowman10 (Apr 2, 2009)

jsloan said:


> Yes, that's the pattern I was thinking of.  Thanks.  Where is that particular spider from?


FL. _maybe_ palm beach...

and sorry for the poor quality pics, snapped em on the fly before school. anyway, this particular variolus (since you asked about markings) is from north FL.


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## jsloan (Apr 2, 2009)

Widowman10 said:


> FL. _maybe_ palm beach...


The reason I asked is that Jeff H has also found _L. mactans_ in Palm beach with similar white markings.  I wonder if his are from the same population, as in a local gene pool (just speculating - wondering if anyone has found seen those markings on spiders outside Florida)?  Check out this thread in the "Araneomorphae" forum (also shows some hourglass variations):

http://araneomorphae.org/viewtopic.php?f=39&t=149&start=0



Widowman10 said:


> this particular variolus (since you asked about markings) is from palm beach.


Interesting brown on the legs.  A hybrid or do you see that often in _L. variolus_?  Thanks for the pics.

I hope to get some _Latrodectus_ myself before long.  I'll be travelling to southern Alberta toward the end of May to look for _L. herperus_ (don't have them in the northern parts of the province).  Also, I might be ordering _L. bishopi_, _L. geometricus _and _L. mexicana _from a supplier in the near future as well.  I'll be putting at least one of these in a large aquarium so it can build a *big* web.


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