L.Hesperus

[Nick G]

Hi folks,

I'm a new member and just took 3 per-chance photos of what is likely a female Lactrodectus Herspurus.I say that 'cause I'm in California, and just conversed with an expert in WA who stated to me that L.Mactans isn't that common in the West.There were 2 other individuals in the web, or near the web.I didn't get shots of those.One I believe was the male, being smaller,slender, and totally different looking.The other was likely a more immature female, as it was far less bulbous, smaller, but had the exact black,shiny coloration with a perfect hourglass.

 

[cacoseraph]

cool man

as far as i know we don't have mactans in CA, just hesperus in the wild

 

[Nick G]

.

You're right.The ones I've seen have usually been in and around buildings, under objects, water heaters, etc.This one was in between some shrubbery/foliage in a desnse field.I have heard of Loxosceles Laeta being seen around the Los Angeles area,but never knew if it was confirmed or just a rumour.There seems to be more "mix-ups" with the smaller Loxosceles Reclusa than any spider I can think of as far as geographics.

 

[Rizzolo]

l. Variolus in N. CA

the widows that i have collected in the SF Bay Area and in the Monterey Bay area have all been L. variolus - two distinctly separate black triangles on the ventral abdomen and no other markings that i could see. The one i collected personally were outside in holes in the ground (abandoned burrows).

 

[Nick G]

the widows that i have collected in the SF Bay Area and in the Monterey Bay area have all been L. variolus - two distinctly separate black triangles on the ventral abdomen and no other markings that i could see. The one i collected personally were outside in holes in the ground (abandoned burrows).

Yeah, I've never caught or seen one of those.I have read they occur mostly in woodlands and prefer to inhabit more secluded areas than L.Mactans or L.Hersperus.

 

[cacoseraph]

the widows that i have collected in the SF Bay Area and in the Monterey Bay area have all been L. variolus - two distinctly separate black triangles on the ventral abdomen and no other markings that i could see. The one i collected personally were outside in holes in the ground (abandoned burrows).

i think those are hesperus too, actually. i'm medium sure i read we only have hesperus in CA

hesperus can have virtually no hourglass, a broken hour glass, or a perfect hourglass
they can be almost perfectly black and range into pretty intricate ventral AND dorsal markings in white, orange, and red on the abdomen.

these are all mature females, i'm talking about here, that i personally have seen or collected

edit: let me see if i can find some quick range data
L. hesperus
"Western black widows live in the warmer western regions of the United States. Their range includes extreme southwestern Canada, south into Mexico along the Pacific coast, and east to Texas, Oklahoma and Kansas. This species can be found in all four of the deserts of the American southwest."
http://bugguide.net/node/view/26346

L. mactans
"It ranges as far north as southern New York, as far south as Florida, and as far west as Texas, Oklahoma, and Kansas. (L. mactans has been found in California, possibly indicating that it can be found in any southern state.) The Southern black widow spider also occurs throughout all four deserts of the American southwest.



In addition, Latrodectus mactans has been found in parts of southern Canada."
http://bugguide.net/node/view/26336
i have a tiny problem with the Cali reference there... most of the books and stuff i have read indicate TX is the western edge of it's territory


L. variolus
"The Northern Black Widow is typically considered an "East Coast" spider, it occurs from northern Florida to south-eastern Canada. This species is most common in the northern part of its range."
http://bugguide.net/node/view/26421

and for kicks and grins

L. bishopi
"It has been found primarily in sand-pine scrub habitats in central and southeast Florida, specifically from Marion County to Martin County."
http://bugguide.net/node/view/26290

L. geometricus
"World wide in the tropical zone. It was introduced in Florida and has since been observed moving north through Georgia, and into South Carolina; it has also been officially recorded in California, Alabama, Mississippi, and Texas."
http://bugguide.net/node/view/23403

 

[Nick G]

Hasselti

I think I read that L.Variolus can also be found in Europe.(but my memory could be wrong) I'm sure everyone here has caught & seen False Widows,usually Steatoda Grossa. But I've seen pics of Steatoda Paykulliana,....and its kinda amazing how it superficially resembles the "Red Back" spider, L.Hasselti,the Black Widow in Austrailia and regions in that part of the world.

 

[tom]

loxosceles laeta and Latrodectus hesperus

Loxosceles laeta population , occurs for nearly thirty years in one building in los Angeles, California, that much is verified by R. Vetter.L variolus does not occur in California, it prefers more damp habitats,like northeast or British Columbia,wghere it is common in undisturbed woods.I did find some l. hesperus resembling l. variolus,but this is described earlier in literature by B.J.Kaston:hourglass shape can vary considerably in populations.Also size difference, females of L. hesperus are much larger than L.variolus.L .reclusa is more widespread than before ,but so is L.rufescens even in New York City...Cheers ,Tom

 

[cacoseraph]

Loxosceles laeta population , occurs for nearly thirty years in one building in los Angeles, California, that much is verified by R. Vetter.L variolus does not occur in California, it prefers more damp habitats,like northeast or British Columbia,wghere it is common in undisturbed woods.I did find some l. hesperus resembling l. variolus,but this is described earlier in literature by B.J.Kaston:hourglass shape can vary considerably in populations.Also size difference, females of L. hesperus are much larger than L.variolus.L .reclusa is more widespread than before ,but so is L.rufescens even in New York City...Cheers ,Tom

i ALWAYS keep my eyes open for those laetas (i live by Los Angeles). i would love to have some in my collection

 

[buthus]

the widows that i have collected in the SF Bay Area and in the Monterey Bay area have all been L. variolus - two distinctly separate black triangles on the ventral abdomen and no other markings that i could see. The one i collected personally were outside in holes in the ground (abandoned burrows).

You really can't ID widows using the hour glass. There is far too much variation. Now and then I run into hesperus groups that have seperated hour glass and even single triangles or a single tri with a small dot above it. I had one a few years ago that had a single tri but it was a perfect heart ...I named her valentine. Even dordsal markings can be confusing. But, variolus usually have white stripes ...usually three on each side are visable. Though, some only have upper dorsal dots (actually its thrying to be a stripe, but it gets segmented) They also tend to have thin white circle or horseshoe near the front of the dorsal. But, again using something like the later to ID could steer one wrong ...example: this year many of the hesperus that I have in my yard have this horseshoe.
Eggsacs and males may be the best way to ID widows ...but there can be problems there also. Variolus sacs can look like hesperus sacs, but tend to be a bit greyish in color compared to hesperus. Both hesperus and variolus sacs have a flat edge or nipple at the top.

I or someone needs to start a serious widow ID thread. There seems to be a lot of interest in Latros here and I have a feeling there is probably a couple experts on the subject lurking about. I myself have been VERY confused and intrigued with what I have been occasionally finding in my area (los angeles) ...especially in my yard this year. I do believe Mactan genes has infiltrated the hesperus population in a small amount. I currently have two males that do not look like hesperus males because they have larger/rounder abdomons. I have never seen males out here like this before. Also, for 7 years of collecting in LA, I have only caught a few hesperus fems that retain dorsal markings and this is usually but a dot of red near the spinneret ...the beginning of the dorsal stripe. But, this year I have found several fems that have a much more apparent red dorsal stripe. These also tend to have a more chocolate brown abdomon. I have kept them of course ..hoping to get some sacs for a possible better ID. Only one was gravid when I caught her and her first sac was strange...tan like the usual hesperus sacs, but much more oval. Ive seen this before with hesperus, so not a good clue there. And, her second sac looks like a usual hesperus sac. I have another that I raised from sling that has a nice dorsal line about a third of the dorsal length and she is ready now to be paired off with one of the oddball males I mentioned above. If there is truely mactan blood here, maybe I can bring some more of it out with the brood.

Will try and document some of this with pics and post.

 

[Venom]

i ALWAYS keep my eyes open for those laetas (i live by Los Angeles). i would love to have some in my collection

Eeek, I certainly wouldn't keep one. Too heinous an envenomation if I messed up and got tagged...

I'll keep my eyes peeled for ya though, as I have had a couple L.leatas up for ID requests on other sites.

 

[Nick G]

Loxosceles

Loxosceles laeta population , occurs for nearly thirty years in one building in los Angeles, California, that much is verified by R. Vetter.L variolus does not occur in California, it prefers more damp habitats,like northeast or British Columbia,wghere it is common in undisturbed woods.I did find some l. hesperus resembling l. variolus,but this is described earlier in literature by B.J.Kaston:hourglass shape can vary considerably in populations.Also size difference, females of L. hesperus are much larger than L.variolus.L .reclusa is more widespread than before ,but so is L.rufescens even in New York City...Cheers ,Tom

You're absolutely correct.I talked to Mr.Vetter via email about 3 years ago & he said more spider bites are "incorrectly" blamed on L.Reclusa that possibly any other spider.I think Laeta (Chilean Recluse) has the more virulent toxin of all the Loxosceles spiders.

 

[Nick G]

Black Widows

Late last night I found two more Widows, this time I was intentionally searching for one.It was near my dwelling and they're pretty common in Southern CA., if not everywhere.These had made their webs in and around a telephone pole,with one being an immature female that was larger then her female counterpart/neighbor.If you look around buildings or structures at night at the bottoms of things with a flashight, I think you will eventually discover one or more.I didn't take any shots of these as I want to get the better camera next time around.I may capture one of these individuals,though.My hunch is that one of their favorite haunts has gotta be under the concrete/metal water meter lids in the sidewalk.I'm sure they can be found there pretty regularly.

 

[JPD]

Late last night I found two more Widows, this time I was intentionally searching for one.It was near my dwelling and they're pretty common in Southern CA., if not everywhere.These had made their webs in and around a telephone pole,with one being an immature female that was larger then her female counterpart/neighbor.If you look around buildings or structures at night at the bottoms of things with a flashight, I think you will eventually discover one or more.I didn't take any shots of these as I want to get the better camera next time around.I may capture one of these individuals,though.My hunch is that one of their favorite haunts has gotta be under the concrete/metal water meter lids in the sidewalk.I'm sure they can be found there pretty regularly.

Sad that I have to travel two hours to collect any!

 

[JPD]

You really can't ID widows using the hour glass. There is far too much variation. Now and then I run into hesperus groups that have seperated hour glass and even single triangles or a single tri with a small dot above it. I had one a few years ago that had a single tri but it was a perfect heart ...I named her valentine. Even dordsal markings can be confusing. But, variolus usually have white stripes ...usually three on each side are visable. Though, some only have upper dorsal dots (actually its thrying to be a stripe, but it gets segmented) They also tend to have thin white circle or horseshoe near the front of the dorsal. But, again using something like the later to ID could steer one wrong ...example: this year many of the hesperus that I have in my yard have this horseshoe.
Eggsacs and males may be the best way to ID widows ...but there can be problems there also. Variolus sacs can look like hesperus sacs, but tend to be a bit greyish in color compared to hesperus. Both hesperus and variolus sacs have a flat edge or nipple at the top.

I or someone needs to start a serious widow ID thread. There seems to be a lot of interest in Latros here and I have a feeling there is probably a couple experts on the subject lurking about. I myself have been VERY confused and intrigued with what I have been occasionally finding in my area (los angeles) ...especially in my yard this year. I do believe Mactan genes has infiltrated the hesperus population in a small amount. I currently have two males that do not look like hesperus males because they have larger/rounder abdomons. I have never seen males out here like this before. Also, for 7 years of collecting in LA, I have only caught a few hesperus fems that retain dorsal markings and this is usually but a dot of red near the spinneret ...the beginning of the dorsal stripe. But, this year I have found several fems that have a much more apparent red dorsal stripe. These also tend to have a more chocolate brown abdomon. I have kept them of course ..hoping to get some sacs for a possible better ID. Only one was gravid when I caught her and her first sac was strange...tan like the usual hesperus sacs, but much more oval. Ive seen this before with hesperus, so not a good clue there. And, her second sac looks like a usual hesperus sac. I have another that I raised from sling that has a nice dorsal line about a third of the dorsal length and she is ready now to be paired off with one of the oddball males I mentioned above. If there is truely mactan blood here, maybe I can bring some more of it out with the brood.

Will try and document some of this with pics and post.

It sounds as though the L.hesperus with the posterior mark above the spinnerettes may in fact be L.mactans. The red "dot" is kind of a telltale sign.
It is probably very likely that there has been some sort of hybridization in some sense of the word between L.mactans and L.hesperus. The offspring would be rendered sterile though.

 

[Nick G]

Well tonight I saw the larger of the two widows, with a throng of newly hatched spiderlings out in front of her,not far from a retreat in between a metal railing at the bottom of the telephone pole.A number of years back I caught one that had made her web in an old plastic paint bucket,with her egg sac.They vanish into their "den" at the slightest disturbance.They are very wary.