# Possible for a Redback spider to be in the US?



## WiseWarrior

I live in the US, Oregon to be specific. When I was a kid I loved collecting spiders, and remember seeing one that looked EXACTLY like a Redback spider. I tried catching it but it ran under a bush, which, while making me very disappointed back then, was definitely a good thing if it somehow was a Redback. Is it possible for a spider ingenious to Australia to be found in the US? Or are there similar-looking spiders that reside in the US? And if so, what are they called? Thanks!


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## pperrotta03

I think maybe it could have been a black widow. Their "hourglass" shape on the abdomen is almost never the case. Maybe it was born with a red line on its back?


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## The Snark

Yes there are versions that look like Hasselti in the US. Latrodectus has exported itself almost everywhere in the world. They were found in packing crates on scientific expeditions to the north and south poles. However, just because they turn up somewhere doesn't mean they can survive the A, climate, B, the habitat and C, the local competition. So far Hasselti has not been able to overcome C in the rare instances they have turned up in North America. IE, the climate and environment are suitably similar but when they turn up near shipping ports it's rare and they have never been found spreading out and establishing themselves. Most likely that is because we have a lot of predators as the steatoda they haven't encountered and adapted to live among in their native habitats.

Reactions: Like 4 | Informative 1


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## VictorHernandez

Most likely lacrodectus spp.


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## The Snark

For ID of Hasseltii the Wiki page is excellent. https://en.wikipedia.org/wiki/Redback_spider
For the N. A. versions, Widowman's site : https://sites.google.com/site/widowman10/widows/comparison-of-the-north-american-widow-species


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## Smokehound714

Latrodectus variolus and hesperus sub-adults resemble redbacks sometimes.  Adults rarely also have a red stripe on the back.

  Definitely possible if produce from australia came here. (LOL)   ..The heck does australia export to the USA, anyway?   I wanna make a crude stereotype and say eucalyptus Hahaha..

Reactions: Funny 1


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## pitbulllady

Was the spider in question in a web when you found it, or just running around "free range"?  There are some species of Salticids and _Castianieras_ that have a red stripe running down the top of their abdomens, and the _Castianieras_ are FAST, so if one wanted to run under a bush, that would be pretty much a lost cause of catching it.  _Latrodactus_ are pretty clumsy running around on the ground, and most of the time, when disturbed in their webs, will just ball up and drop to the floor or ground and "play dead" instead of running.  I have seen both _L. mactans & L. variolas_ with a stripe, though it was not as uniform as that of a _L. hassalti_, and I assume that _L. hesperus_  would occasionally exhibit this pattern, as well.  Now, I have also seen, and bought, _L. hassalti_ at reptile shows, so they ARE being imported, but the most likely case is something native to the US, either something that's not a Widow at all, or one of our native Widows.

pitbulllady

Reactions: Like 2


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## SleazyDutcham

I once again live in the eastern panhandle of WV, where I grew up. Over the years here and my parents and I have spotted a few _L. mactans_ or southern black widows. I recently came across a mud dauber wasp nest for the first time, not knowing what it was and thinking it was an abandoned insect nest of some kind. It was located in a door frame that is a primary entry way into my home, so it needed to be destroyed. I was *VERY *surprised to see the spiders inside when I started breaking it apart. One of the first spiders I saw had a remarkable color pattern on the back. A quick google search made me think it was simply _L. mactans_, but after a few days of researching creepy crawlies and looking at pictures, I am convinced it is actually _L. hasseltii.
_
I know this post is old, but if anyone is able to identify this spider (image and link below) I would _very_ thankful. It would be nice to know if these are possibly in and around my home.

http://imgur.com/a/nWb4R


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## The Snark

The white bands and broken stripe on the back are typical of juvenile Hasseltii. If you keep it and the white disappears while the red joins into a single stripe, it be Hasseltii. That would definitely be worth taking to a local university. Head scratching time how it got there.
Recent reports have them turning up in Europe and Japan.


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## Toxoderidae

The Snark said:


> The white bands and broken stripe on the back are typical of juvenile Hasseltii. If you keep it and the white disappears while the red joins into a single stripe, it be Hasseltii. That would definitely be worth taking to a local university. Head scratching time how it got there.
> Recent reports have them turning up in Europe and Japan.


He killed the spider, as most people do

Reactions: Sad 1


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## The Snark

Well nuts. Thought he just did in the wasps. Oh well. 
Seems to be almost certainly a Hasseltii too. Wondering what it was doing so far away from a shipping port. Only alternative would be Variolus which it isn't.

Just rescued a Katydid from the cat. Largest I've ever seen. About 5 inches head to wing tips.


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## Python

L. mactans juices and males look like that and I'd bet that's what it is. I've raised widows for years, mactans mostly, and that is a typical juvenile. I've had many mactans retain so.e or all their juvenile coloration into adulthood. I even tried breeding for a particular pattern that was pretty cool but I only got 4 offspring from the female that had it before she died of old age and those produced many aberrant patterns but none like the original. I found that red spots were common on the back and sometimes they blended together to make a stripe. In fact, almost every sac I had produced a percentage that had the spots or stripes so I don't think it's as uncommon as might be believed.
One other thing, if the spider was pulled out of the mud nest, it was already doomed. I find those all the time in Alabama and they are paralyzed for the wasp larvae to eat while they grow. I've heard of people being able to care for T's that have been paralyzed by pepsis wasps until the T came around but nothing reliable. This spider was already dead essentially

Reactions: Agree 3 | Informative 1


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## TwitchingShark

Researching what kind of spider was on my front door led me here. Maybe you guys can help me figure it out. I looked at a lot of pictures and can't seem to decide on what I think it is. What do you guys think?  I live in Oklahoma by the way.


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## Python

Definitely a widow, looks like a juvenile female. Maybe Hesperus but could be mactans. I've had many mactans that looked like this even into adulthood. Awesome little girls and insane eaters. They will eat anything that will stick in their web, anything!

Reactions: Helpful 1


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## TwitchingShark

I don't know much about spiders, except to avoid the dangerous ones. This is the 2nd widow I have found in the past week. Do I need to be worried or just a coincidence? I have two girls (5 and 6 years old) and one of them loves to play with bugs. I don't want her to accidentally pick one of these guys up.


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## Python

If you have one you have a lot. They are quite prolific. I wouldn't worry too much though. They are quite reclusive and you may only see a very few. I would definitely educate your girls about the possible dangers of picking up any spiders. They are great to watch but they do not like human contact at all. If they become a problem, just send them all to me and I'll take care of them for you lol

Reactions: Agree 2


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## TwitchingShark

haha. You can have all you want. 

I try to teach them the dangers of things I know about, and research what I don't know. 

Thanks for your input!


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## The Snark

Educate educate educate

This little lady built her web in the wrong location. It was taken apart by the humans very carefully and her coaxed onto the human in a gentle way she did not take as a threat. She was then moved to a more suitable area. In the pic the human is not handling the spider, she is handling the human.

Reactions: Like 1


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## darkness975

Python said:


> If you have one you have a lot. They are quite prolific.


Hopefully the influx of non native _Latrodectus geometricus _does not continue to spread and destroy the environment but as with other similar events it does not look good.

People that are not in the know usually will say "oh it's great because they aren't as dangerous" or whatever but the potential ecological disaster is not worth it.
_Latrodectus _might be famous for having stronger venom than many other spiders but the fear mongering media makes it seem like there are billions of them waiting for you to turn out the light so they can swarm you.   

They are not as commonly encountered as people think but the few cases of bite occurrences are always splashed everywhere.

Reactions: Agree 1


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## Python

That is true. They are not as commonly encountered as people are led to believe, although around here they are in just about every nook and cranny. They are quite common if one is looking for them though. I just wish people would learn as quickly as they fear


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## darkness975

Python said:


> I just wish people would learn as quickly as they fear


Good luck with that I am afraid ...

Speaking of this situation with the_ L_._ geometricus , _does anyone know if they are continuing to spread and if there are any current papers on the subject or current studies being done?


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## Python

I'm sure they are spreading. A couple years ago I found one in my yard. I had never heard of one being anywhere near us till I found her and she was gravid so there were many more that I didn't see.


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## myrmecophile

darkness975 said:


> Hopefully the influx of non native _Latrodectus geometricus _does not continue to spread and destroy the environment but as with other similar events it does not look good.
> 
> People that are not in the know usually will say "oh it's great because they aren't as dangerous" or whatever but the potential ecological disaster is not worth it.
> _Latrodectus _might be famous for having stronger venom than many other spiders but the fear mongering media makes it seem like there are billions of them waiting for you to turn out the light so they can swarm you.
> 
> They are not as commonly encountered as people think but the few cases of bite occurrences are always splashed everywhere.



A while back someone PMed me asking if I would sell them brown widows, I told them no, I killed them when I found them. the following is the response I got them. Ants in general are hardly pest insects. Some people just don't get it. I have no doubt they are continuing to spread, they will continue to wreak ecological havoc where ever the environment is favorable.

"
The spider is a beneficial organism to farmers. What you are doing is counter productive. You'd be better served doing this to ants. I have several organic methods of killing them from use of parasites to specialized viruses. I hope to find even more effective vectors in the new year. The brown widow's success as a beneficial predator is a bar that has been set. We must responsibly eliminate pest insects like ants that damage food crops. Here's to a productive New Year."


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## Fishman

Female Redback Spider
The Business end:-







The Stripe which is so distinguishing











A smaller one, less mature version showing crenelated stripe common to younger ones





Typical mess of web with egg sacs on dark tight space.






Enjoy, they're everywhere here. Nothing to really worry about, just don't put your pants on without shaking them out in the morning.

Reactions: Like 2 | Love 1


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## Widow lover

The Snark said:


> The white bands and broken stripe on the back are typical of juvenile Hasseltii. If you keep it and the white disappears while the red joins into a single stripe, it be Hasseltii. That would definitely be worth taking to a local university. Head scratching time how it got there.
> Recent reports have them turning up in Europe and Japan.





SleazyDutcham said:


> I once again live in the eastern panhandle of WV, where I grew up. Over the years here and my parents and I have spotted a few _L. mactans_ or southern black widows. I recently came across a mud dauber wasp nest for the first time, not knowing what it was and thinking it was an abandoned insect nest of some kind. It was located in a door frame that is a primary entry way into my home, so it needed to be destroyed. I was *VERY *surprised to see the spiders inside when I started breaking it apart. One of the first spiders I saw had a remarkable color pattern on the back. A quick google search made me think it was simply _L. mactans_, but after a few days of researching creepy crawlies and looking at pictures, I am convinced it is actually _L. hasseltii.
> _
> I know this post is old, but if anyone is able to identify this spider (image and link below) I would _very_ thankful. It would be nice to know if these are possibly in and around my home.
> 
> http://imgur.com/a/nWb4R



That's latrodectus variolus.....
   Hasselti juveniles don't look anything like that.


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## Widow lover

TwitchingShark said:


> Researching what kind of spider was on my front door led me here. Maybe you guys can help me figure it out. I looked at a lot of pictures and can't seem to decide on what I think it is. What do you guys think?  I live in Oklahoma by the way.
> 
> View attachment 220981


Juvenile mactans


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## USMuscle9403

I guess it's not entirely impossible for a hasselti to take up residence here, but if it was mature, it may have just been variolus. I've seen L. variolus carry the dorsal stripe well into adulthood.


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## Dustinzor

I live in Colorado and just found this specimen in my bathroom. When I did some internet searching, it looked like a female Redback, but that searching also led me here. What do you guys think?


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## pannaking22

Nope, not a redback. Lots of other markings on the abdomen, whereas _hasselti_ have just the single giant band. My guess would be _hesperus_ but I'm not an expert on widow ID like @Widow lover is.

Reactions: Like 1 | Agree 2


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## Biollantefan54

I agree with L. hesperus

Reactions: Agree 1


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## Widow lover

L


Dustinzor said:


> I live in Colorado and just found this specimen in my bathroom. When I did some internet searching, it looked like a female Redback, but that searching also led me here. What do you guys think?
> View attachment 224697


. Hesperus

Reactions: Agree 1


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## JAFUENTES

Hesperus indeed


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## The Snark

Hasseltti juvenile






(Young Australian redback spider. Taken December 2010 in Sydney, by Phil Bentley (www.localoptimum.com))


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## Malmignatte

Iread some time ago that red backs were in Houston Texas.but so what,usa has plenty of widow spiders and  their all roughly the same in the venom.


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## pannaking22

Malmignatte said:


> Iread some time ago that red backs were in Houston Texas.but so what,usa has plenty of widow spiders and  their all roughly the same in the venom.


Where did you find that? I'd be interested to read it. There shouldn't be any _hasselti_ in Houston, but some of the subspecies of _hesperus _look quite a bit like _hasselti_


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## Ungoliant

pannaking22 said:


> Where did you find that? I'd be interested to read it. There shouldn't be any _hasselti_ in Houston, but some of the subspecies of _hesperus _look quite a bit like _hasselti_


People often mistake juvenile black widows (or even adult _Latrodectus variolus_) with redbacks, because they have red markings on the dorsal side of the abdomen.

Reactions: Agree 1


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## Hanaleblanc

Ok...first time I have ever seen one of these. I'm familiar with a black widow and brown widow and recluse. I'm in Louisiana so weather is good for them here. I know this isn't a great pic but I wasn't getting any closer. Help...bc I will probably loose sleep over this.


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## Ungoliant

Hanaleblanc said:


> I know this isn't a great pic but I wasn't getting any closer. Help...bc I will probably loose sleep over this.


This one is not even a widow spider. It's a harmless antmimic in the genus _Castianeira_, specifically _C. crocata_ or _C. descripta_.

BugGuide does not currently have any submissions of your species from Louisiana, so I'd encourage you to submit it there.


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## Malmignatte

pannaking22 said:


> Where did you find that? I'd be interested to read it. There shouldn't be any _hasselti_ in Houston, but some of the subspecies of _hesperus _look quite a bit like _hasselti_


Iread this some yrs ago right here in this forum and head line read Houston we have a problem.lol


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## OkWyatt

Can someone help me to identify this spider? It was inside a toy outside and brought inside by my kiddo. It was guarding an egg sac.


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## Smokehound714

there are a few people that have them in the USA.  from a small introduced population i believe


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## Ungoliant

OkWyatt said:


> Can someone help me to identify this spider? It was inside a toy outside and brought inside by my kiddo. It was guarding an egg sac.


In immature black widow spider (family Theridiidae, genus _Latrodectus_). Do you have a photo of the egg sac? That can help identify the species.

All three of our native species of black widow can be found in Oklahoma:

southern black widow (_Latrodectus mactans_)
northern black widow (_Latrodectus variolus_)
western black widow (_Latrodectus hesperus_)

While all widow spiders should be considered medically significant, bites from these spiders are rare. They generally occur when a person unwittingly sticks a bare hand into a spider's web, pressing it against the skin.


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## The Snark

Leaving myself wide open to @Ungoliant bellowing 'hair splitting pedant!' at me... five species in NA.

Reactions: Funny 1


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## Ungoliant

The Snark said:


> Leaving myself wide open to @Ungoliant bellowing 'hair splitting pedant!' at me... five species in NA.


I was only listing the species of _black_ widow that one would expect to find in Oklahoma.


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## The Snark

All (T)hree of our native species can be found in Oklahoma.
I'll be under the floorboards if you want me.

Reactions: Funny 1


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## kjmeredith901

Hi All, 

I live in Memphis, TN and found this lady in my garage. A google search led me here. Can you help me identify her? Thanks in advance for your help!


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## kjmeredith901

It has since been suggested to me that this may be a male black widow, so now i feel dumb for calling it "lady". Can anyone confirm this?


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## Ungoliant

kjmeredith901 said:


> It has since been suggested to me that this may be a male black widow, so now i feel dumb for calling it "lady". Can anyone confirm this?


Likely a juvenile black widow. The female _Latrodectus mactans_ will lose these extra markings as she matures. The female _Latrodectus variolus_ has them even as adults. (Males of both species also have extra markings, but this does not look like a mature male.)


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## kjmeredith901

@Ungoliant, Thanks for your help, I very much appreciate the information!

Reactions: Like 1


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## AshleyB

TwitchingShark said:


> Researching what kind of spider was on my front door led me here. Maybe you guys can help me figure it out. I looked at a lot of pictures and can't seem to decide on what I think it is. What do you guys think?  I live in Oklahoma by the way.
> 
> View attachment 220981


I am in Oklahoma City. I have found 2 of these spiders in my house on base. They look a lot like the Redback Spider, but they aren't even "supposed" to be found in the United States. I really have no idea exactly what it is - I HATE spiders... Do you think it is a widow of some sort or a redback given the fairly straight line down the back of the spider?


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## The Snark

AshleyB said:


> Do you think it is a widow of some sort or a redback given the fairly straight line down the back of the spider?


As @Ungoliant has said. And Redbacks are Widows, L. Hasselti.
PS Good luck with your spider phobia. Consider avoiding playful kittens. They cause about 1,000,000 injuries bearing a potential infection for each significant spider bite.

Reactions: Funny 1


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## AshleyB

The Snark said:


> As @Ungoliant has said. And Redbacks are Widows, L. Hasselti.
> PS Good luck with your spider phobia. Consider avoiding playful kittens. They cause about 1,000,000 injuries bearing a potential infection for each significant spider bite.


I appreciate your quick response. My concern is that in the research that I did, the redbacks may require an anti-venom unlike the black widows that are more commonly found in the United States. I have two small children and would prefer to know what I am dealing with if they did ever get bitten for any reason.

PS. I'm not a cat person either, but thanks for the advice.

Reactions: Funny 1


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## The Snark

AshleyB said:


> I appreciate your quick response. My concern is that in the research that I did, the redbacks may require an anti-venom unlike the black widows that are more commonly found in the United States.


The most powerful (LD50-mice) venom in Latros is in a North American species, L Geometricus. However, this is not the determining factor in the (very rare) need for anti-venin.
The determining factor is always the MMO, Means, Method and Opportunity. The most anti-venin ever prescribed for a patient was in fact an Australian man and a Hasselti was involved. The spider was trapped between his body and the bed and bit effectively multiple times. This is extraordinary and extraordinarily rare. The average Latro bite is usually trivial, described by one expert as a warning nip a dog would give. They will always run and hide if at all possible.

Two Latro bites. The red, recent - L Hasselti, and the bump on my knuckle - L Hesperus, 30 years old. Neither was medically significant.






*LD50 values for some of the N.A. Latrodectus species:

Latrodectus geometricus = .43 mg/kg (IV) & .223 mg/kg (IP)
Latrodectus hesperus = .84 mg/kg (IV)
Latrodectus mactans = 1.39 mg/kg (IV) & .90 mg/kg (SC)
Latrodectus bishopi = 2.2 mg/kg (could be IP)
Latrodectus variolus = 1.8 mg/kg (IP)*
(Data from @Widowman10 web site: https://sites.google.com/site/widowman10/)

A report I read from the Museum and Art Gallery, Northern Territory, http://www.magnt.net.au/ had the LD-50 of Hasselti at .60-.85 mg/kg. Equivalent to Hesperus.

Reactions: Informative 1


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## AshleyB

Would the location of the bite look similar on a dog? This looks really comparable to a spot on my dog a few weeks ago. My initial thought is that it must have been a spider that bit him.
Again thanks for your response!


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## The Snark

AshleyB said:


> Would the location of the bite look similar on a dog?


It certainly could, as any similar bite that infused an irritant substance. Examining the skin of the animal, specifically profusion, redness in the skin color normally and how the redness returns after pinching the skin then comparing it to your own skin, would be the best way to determine this.


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## Ungoliant

AshleyB said:


> Would the location of the bite look similar on a dog? This looks really comparable to a spot on my dog a few weeks ago. My initial thought is that it must have been a spider that bit him.


It isn't possible to diagnose a spider bite from the wound alone, even for a physician or veterinarian. (Many more common conditions are mistaken for spider bites.)

Reactions: Like 1 | Agree 5


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## JljenkinsII

The Snark said:


> The white bands and broken stripe on the back are typical of juvenile Hasseltii. If you keep it and the white disappears while the red joins into a single stripe, it be Hasseltii. That would definitely be worth taking to a local university. Head scratching time how it got there.
> Recent reports have them turning up in Europe and Japan.


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## JljenkinsII

This was found at my cabin at Pickwick State Park in Counce Tn.


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## dangerforceidle

Tennessee is in range of _Latrodectus mactans_ and _L. variolus_.  I would suspect a sub-adult of one of these species, as both can have red dorsal markings (as Ungoliant stated above).

Redback spider specifically refers to the Australian _Latrodectus hasselti_, but other widows can have red markings as juveniles or as adults.  Check out _L. tredecimguttatus _for example:

Reactions: Like 3 | Informative 1


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## pannaking22

JljenkinsII said:


> This was found at my cabin at Pickwick State Park in Counce Tn.


Looks like variolus, though it still could be mactans. Definitely not L. hasselti.

Love me some treds, @dangerforceidle, always happy to see pics of them

Reactions: Like 1 | Agree 2


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## dangerforceidle

pannaking22 said:


> Love me some treds, @dangerforceidle, always happy to see pics of them


I find widows in general to be a very alluring and beautiful genus, but there is something else about the more interestingly marked species.  I would put _L. variolus_ up there, too, with their occasional white and red stripes.

Reactions: Agree 1


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## Georeynolds

This guy sure looks like pictures on the web of a redback. She was found on the plateau in east Tennessee and has a solid red stripe on her back. Thoughts?


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## myrmecophile

Just a nicely marked eastern.


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## dangerforceidle

All "black widow" species can retain the red stripe on their dorsal side, it's just less common in US species than it is for _L. hasselti_ in Australia.  Australia's red back is also a "black widow" species.

In Tennessee you will find _L. mactans_ and _L. variolus_.

Reactions: Agree 1


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## Veigar

If someone were to theoretically go to Australia, take like 5 Redback eggsacs, and then let them hatch in the wild, say, in the western US, what would happen? (I understand it'd be not good, but it'd be pretty interesting to see how they'd cope with their North American counterparts)


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## myrmecophile

My hope is that every single one of the hatchlings would die horrible gruesome deaths.


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## NYAN

Veigar said:


> If someone were to theoretically go to Australia, take like 5 Redback eggsacs, and then let them hatch in the wild, say, in the western US, what would happen? (I understand it'd be not good, but it'd be pretty interesting to see how they'd cope with their North American counterparts)


In southern California, it is a medeterranian climate just like southwestern Australia. If redbacks were to somehow hatch there it would be likely they would be outcompete by the native and non native animals first off, but the conditions, especially in urban areas might offer a  favorable environment and a few could survive. Luckily the chances of this happening are very unlikely, not a ton of people have redbacks as they are somewhat rare still in the USA, and those who do have them are responsible I would hope and wouldn’t allow any escapes.


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## The Snark

Veigar said:


> (I understand it'd be not good, but it'd be pretty interesting to see how they'd cope with their North American counterparts)


I'd agree there. I've often wondered about the bridge between new world, old world, and the Lemurian and how, when and where Latro crossed it.


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## Dradicus

Hello, much like others here, I have been brought here for research. I am visiting family in south western VA this week and happened to walk out to grab something from my truck after dark. I think spiders are awesome and I’d hate to kill them but I want to error on the safe side just in case. As I was walking out I noticed a very large web with a pretty decent sized spider in it. I went to grab a flashlight and my phone and it had retreated to a round web a little smaller than a tennis ball. They are black with red stripes on their backs. There are three different webs with three spiders and once I took the pictures I noticed the little ones. Anyone help me out here? Might have to zoom in a little.


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## NYAN

Dradicus said:


> Hello, much like others here, I have been brought here for research. I am visiting family in south western VA this week and happened to walk out to grab something from my truck after dark. I think spiders are awesome and I’d hate to kill them but I want to error on the safe side just in case. As I was walking out I noticed a very large web with a pretty decent sized spider in it. I went to grab a flashlight and my phone and it had retreated to a round web a little smaller than a tennis ball. They are black with red stripes on their backs. There are three different webs with three spiders and once I took the pictures I noticed the little ones. Anyone help me out here? Might have to zoom in a little.


It’s a latrodectus sp. could be mactans or variolus. Quite a beautiful female, and a little bit higher up than I usually see widows. She won’t bother anyone as long as no one sticks their hands in her web. As with all widows they are shy in nature and do have a powerful venom but would rather use it on food. The ‘little spiders’ are actually old molts by the looks of it. If there are other questions or concerns please feel free to post more.

Reactions: Agree 1


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## NYAN

Latrodectus hasselti enjoying her weekly dinner



__ NYAN
__ Jun 23, 2018
__ 4
__
hasselti
latrodectus
latrodectus hasselti
redback spider
theridiidae




						This female has developed far quicker than the other 11. It’s interesting because they are the...
					




Here’s a pic of what the dorsal pattern looks like on latrodectus hasselti aka the redback. This is a subadult female of mine.


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## Quetzalcoatl Nyarlathotep

The Snark said:


> The most powerful (LD50-mice) venom in Latros is in a North American species, L Geometricus. However, this is not the determining factor in the (very rare) need for anti-venin.
> The determining factor is always the MMO, Means, Method and Opportunity. The most anti-venin ever prescribed for a patient was in fact an Australian man and a Hasselti was involved. The spider was trapped between his body and the bed and bit effectively multiple times. This is extraordinary and extraordinarily rare. The average Latro bite is usually trivial, described by one expert as a warning nip a dog would give. They will always run and hide if at all possible.
> 
> Two Latro bites. The red, recent - L Hasselti, and the bump on my knuckle - L Hesperus, 30 years old. Neither was medically significant.
> 
> 
> 
> 
> 
> 
> 
> *LD50 values for some of the N.A. Latrodectus species:
> 
> Latrodectus geometricus = .43 mg/kg (IV) & .223 mg/kg (IP)
> Latrodectus hesperus = .84 mg/kg (IV)
> Latrodectus mactans = 1.39 mg/kg (IV) & .90 mg/kg (SC)
> Latrodectus bishopi = 2.2 mg/kg (could be IP)
> Latrodectus variolus = 1.8 mg/kg (IP)*
> (Data from @Widowman10 web site: https://sites.google.com/site/widowman10/)
> 
> A report I read from the Museum and Art Gallery, Northern Territory, http://www.magnt.net.au/ had the LD-50 of Hasselti at .60-.85 mg/kg. Equivalent to Hesperus.




L. Geometricus is an African species of Latrodectus. L. Hesperus actually has the lowest LD-50 out of all north American widows, southerns being right in the middle, and norterns being more toxic than both, yet, not as aggressive as a southern widow. As well, L. Geometricus should be viewed as an invasive species, as it kills of native black widows. The worship of non-native species ends. Revere that which is within your back-yard, and do not envy the foliage of your neighbors.


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## NYAN

Geb Arachnia Whitney said:


> L. Geometricus is an African species of Latrodectus. L. Hesperus actually has the lowest LD-50 out of all north American widows, southerns being right in the middle, and norterns being more toxic than both, yet, not as aggressive as a southern widow. As well, L. Geometricus should be viewed as an invasive species, as it kills of native black widows. The worship of non-native species ends. Revere that which is within your back-yard, and do not envy the foliage of your neighbors.


My understanding is that mactans is the most potent of the North American species and bishopi/geometricus is the least. I’ve heard about geometricus being the most toxic, but they aren’t considered medically significant.


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## Quetzalcoatl Nyarlathotep

L. Variolus

"The LD-50 has been measured in mice as 1.20–2.70 mg (0.019–0.042 gr); each spider contains about 0.254 mg (0.0039 gr) of venom.[4]

Unlike for the related _Latrodectus mactans_, as of 2015 no antivenom was available"

L. Mactans


The LD-50 of _L. mactans_ venom has been measured in mice as 1.39 mg/kg,[25] and separately as 1.30 mg/kg (with a confidence interval of 1.20–2.70).[26]

L. Hesperus & L. Mactans


"The mouse LD50 values for L. hesperus and L. mactans venoms were 1.64 mg/kg and 1.26 mg/kg, respectively. In the efficacy trial, all mice in group 3 (L. hesperus or L. mactans venom and protein control) died. In both experiments, all mice in group 4 (L. hesperus or L. mactans venom + antivenom) survived (p < 0.0001)."


Venom potency has a great deal to do with how often the widow eats, for if she is malnourished her venom will be much more toxic. It is harder than all hell to find any decent articles on the LD50 of L. Hesperus without reading a bunch of fluff.


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## NYAN

Geb Arachnia Whitney said:


> L. Variolus
> 
> "The LD-50 has been measured in mice as 1.20–2.70 mg (0.019–0.042 gr); each spider contains about 0.254 mg (0.0039 gr) of venom.[4]
> 
> Unlike for the related _Latrodectus mactans_, as of 2015 no antivenom was available"
> 
> L. Mactans
> 
> 
> The LD-50 of _L. mactans_ venom has been measured in mice as 1.39 mg/kg,[25] and separately as 1.30 mg/kg (with a confidence interval of 1.20–2.70).[26]
> 
> L. Hesperus & L. Mactans
> 
> 
> "The mouse LD50 values for L. hesperus and L. mactans venoms were 1.64 mg/kg and 1.26 mg/kg, respectively. In the efficacy trial, all mice in group 3 (L. hesperus or L. mactans venom and protein control) died. In both experiments, all mice in group 4 (L. hesperus or L. mactans venom + antivenom) survived (p < 0.0001)."
> 
> 
> Venom potency has a great deal to do with how often the widow eats, for if she is malnourished her venom will be much more toxic. It is harder than all hell to find any decent articles on the LD50 of L. Hesperus without reading a bunch of fluff.



Are you copying a wikipedia article? Ive Found contradicting information from several different sources, both listing mactans to be more potent. The study you’re referencing is also around 90 years old. Do you have a source on the venom potency fluctuating with how well fed the spider is? I could see it being true. If it is, then these tests can’t be certain. 

https://www.ncbi.nlm.nih.gov/m/pubmed/11407496/

The university of New Mexico lists mactans as being 0.55 also.


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## Quetzalcoatl Nyarlathotep

NYAN said:


> Are you copying a wikipedia article? Ive Found contradicting information from several different sources, both listing mactans to be more potent. The study you’re referencing is also around 90 years old. Do you have a source on the venom potency fluctuating with how well fed the spider is? I could see it being true. If it is, then these tests can’t be certain.
> 
> https://www.ncbi.nlm.nih.gov/m/pubmed/11407496/
> 
> The university of New Mexico lists mactans as being 0.55 also.




The fluctuation of venom potency makes sense with the varied results on the LD50. I read through as many articles I could find then I averaged the numbers accordingly to that which I found. I did source the first two from Wikipedia, the third, I sourced from https://www.ncbi.nlm.nih.gov/pubmed/11407496 

Furthermore, I find that many scientists provide rushed data, whereas a "hobbyist" actually studies the data in action. For instance, When I would feed my L. Variolus, I would never keep a set schedule, but I did keep the prey a constant species. On days which she had fed previously the night before, her prey would struggle for a good 15 minutes or so before paralysis kicked in. However, on days that I had not fed her a week prior, or when she had an egg sac in her web, the same adult female black field crickets would be paralyzed 5-7 minutes tops. And this occurred on multiple occasions during my experiments with her.


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## The Snark

Venom potency: https://sites.google.com/site/widowman10/venom

Gee thanks, globalization. We now have Hasseltii, Mactans, Hesperus and Dahli in Thailand. Meanwhile, Hesperus, apparently fed up competing with Geometricus has moved to Israel.

Reactions: Award 1


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## Smokehound714

nobody even knows where brown widows originate from because they're cosmopolitan in range.   they're commensals with humans and fail to thrive away from houses and irrigation.  

 Some believe they're african, others believe they're australasian or south-american.  

 The claim that they have the strongest venom is also bunk, I used to force them to bite me to prove to people they arent dangerous.  the venom seems no more potent than a steatoda bite IMO.  Well at least for me.


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## Quetzalcoatl Nyarlathotep

The Snark said:


> Venom potency: https://sites.google.com/site/widowman10/venom
> 
> Gee thanks, globalization. We now have Hasseltii, Mactans, Hesperus and Dahli in Thailand. Meanwhile, Hesperus, apparently fed up competing with Geometricus has moved to Israel.



Finally, an actual report! Thank you kindly Mr. Snark... Now I can begin the real studying!


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## Quetzalcoatl Nyarlathotep

Latrodectus hesperus = .84 mg/kg(IV)
Latrodectus mactans = 1.39 mg/kg (IV) & .90 mg/kg (SC)
Latrodectus bishopi = 2.2 mg/kg (could be IP)
Latrodectus variolus = 1.8 mg/kg (IP)

I can agree with these. Fascinating that L. Variolus has the potential to be the largest of the American widows! You gave me a gold mine Mr. Snark. You get an award.


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## The Snark

Smokehound714 said:


> they're commensals with humans and fail to thrive away from houses and irrigation.


Can you direct us to a white paper on that? Feels a lot like a typical invasive finding niches in ecosystems, but extremely hyper.



Smokehound714 said:


> Some believe they're african, others believe they're australasian or south-american.


True cosmopolitan opportunists. Give globalization, human stupidity, and a few more decades I suspect the African bee will show very similar omnipresence.

Reactions: Like 1


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## Quetzalcoatl Nyarlathotep

Damn Brown widows... Damn them to the mantle of earths layers... Soon they will kill off all native widow species if we don't eradicate them first...


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## The Snark

Geb Arachnia Whitney said:


> Damn Brown widows... Damn them to the mantle of earths layers... Soon they will kill off all native widow species if we don't eradicate them first...


If it's like @Smokehound714 says all over I suspect it will be like the Himalayan blackberry invasion in the pacific northwest. Essentially, obvious plans to take over the planet. However, environmental limiting factors came into play. So Geos prefer human habitation and are displacing Hesperus. But Hesperus has a huge range and widely differing environments. From the cold and constantly damp pacific northwest to the alkali flats on borders of death valley and south past the Salton Seat into Mexico. Opportunity invasives rarely are able to tolerate all the niches that the local animal populations have adapted to.

Reactions: Informative 1


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## NYAN

The Snark said:


> Venom potency: https://sites.google.com/site/widowman10/venom
> 
> Gee thanks, globalization. We now have Hasseltii, Mactans, Hesperus and Dahli in Thailand. Meanwhile, Hesperus, apparently fed up competing with Geometricus has moved to Israel.


Are you sure abour Hesperus and mactans being in Asia? I know of geometricus and hasselti being invasive, but not those two. I would be interested in reading more about this if so.


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## The Snark

NYAN said:


> Are you sure abour Hesperus and mactans being in Asia?


A friend brought a foreigner  associate to my house two weeks ago and asked if I could ID a spider. Across the river from me about 3-4 hundred meters off. Several holes under a shipping container with that tell tale web. They had their workers dig out the area and unearthed a typical Hesperus. Asking where the container came from: Sat in San Pedro for a couple of months before coming here.
Similar incidents are popping up everywhere. Down in Phitsanulok they had several widows turn up. Containers nearby came from Jacksonville, Florida.
Just a question of if they establish themselves.
I mentioned a probable widow to Rod Crawford a few years back. He wasn't surprised at all. Said it was only a matter of time considering how metropolitan widows are.

Meanwhile down in Den Chai a man died from a necrotic wound. L Recluse was found and positively identified. We had no dangerous spiders here hence the man ignored the bite.

Reactions: Like 1 | Informative 1


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## NYAN

The Snark said:


> A friend brought a foreigner  associate to my house two weeks ago and asked if I could ID a spider. Across the river from me about 3-4 hundred meters off. Several holes under a shipping container with that tell tale web. They had their workers dig out the area and unearthed a typical Hesperus. Asking where the container came from: Sat in San Pedro for a couple of months before coming here.
> Similar incidents are popping up everywhere. Down in Phitsanulok they had several widows turn up. Containers nearby came from Jacksonville, Florida.
> Just a question of if they establish themselves.
> I mentioned a probable widow to Rod Crawford a few years back. He wasn't surprised at all. Said it was only a matter of time considering how metropolitan widows are.
> 
> Meanwhile down in Den Chai a man died from a necrotic wound. L Recluse was found and positively identified. We had no dangerous spiders here hence the man ignored the bite.


Interesting. Loxosceles recluse doesn’t kill healthy adults usually. That package with Hesperus came from very close to where I live, cool. I suppose it’s possible for them to lay eggs and for them to hatch. I imagine that the populations would be very enclosed at first though. What a time we live in..

Reactions: Optimistic 1


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## The Snark

NYAN said:


> Loxosceles recluse doesn’t kill healthy adults usually.


Take into account how stoic the average farmer is, the fact he knew he got bit by a spider and they are harmless, and most farmers don't go to medical centers but instead to clinics where nurses or techs handle the work load and a doc breezes through now and then. I've been by our neighborhood clinic a couple dozen times and have yet to see a doc. And then to top it off, most of the hospitals here are government operated where Docs get around $3 to $5  per patient seen and let's just say the overall medical quality and capability are lacking. Thai's are also usually one trick ponys. Thinking outside their little boxes is virtually unheard of. So spider bite? Take paracetomol and check back in a few days if it doesn't get better.

By the rough time frame I put together with the envenomed farmer, it went from weeping open sore to systemic in less than 24 hours. Official cause of death, "heart and lung failure" which is nicely vague and meaningless.

Reactions: Funny 1


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## Widowman10

The Snark said:


> Venom potency: https://sites.google.com/site/widowman10/venom


Right on! Thx @The Snark 

I put quite a bit of work into finding those values, but I'm not sure I saved the sources or could recall exactly where I found all of them. I remember reading differing reports of values as well, so I went with the more trusted/recent studies for those values. Some species were not studied very thoroughly either.

Reactions: Like 2


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## Quetzalcoatl Nyarlathotep

Widowman10 said:


> Right on! Thx @The Snark
> 
> I put quite a bit of work into finding those values, but I'm not sure I saved the sources or could recall exactly where I found all of them. I remember reading differing reports of values as well, so I went with the more trusted/recent studies for those values. Some species were not studied very thoroughly either.


There's hope for Variolus yet!


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## KES

I’ve seen several of these in my yard in Oklahoma. Is this typical? I was expecting the markings to be more hour glass shaped due to our location.


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## NYAN

KES said:


> View attachment 313460
> 
> 
> 
> 
> 
> 
> 
> 
> 
> I’ve seen several of these in my yard in Oklahoma. Is this typical? I was expecting the markings to be more hour glass shaped due to our location.


You’re looking at the wrong side if you want to see an hourglass. Contrary to popular belief, (Likely due to people’s tattoos and art) the hourglass is on the ventral side. As for the dorsal pattern it is perfectly normal for the species, Latrodectus mactans. I think this one is a molt or two from maturity so the red may disappear a bit.

Reactions: Agree 3


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## HippyMom121518

Just moved to Williamson Rv park in Conway, South Carolina and found this beauty on the power supply hook ups. Can anyone help me identify? I have a 4 year old daughter and a 7 year old son and dont want anyone or anything hurt so id like help with identification and tips on removal or what would be best because either way she's gotta go and will be way too close for comfort! Thanks in advance!


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## NYAN

HippyMom121518 said:


> Just moved to Williamson Rv park in Conway, South Carolina and found this beauty on the power supply hook ups. Can anyone help me identify? I have a 4 year old daughter and a 7 year old son and dont want anyone or anything hurt so id like help with identification and tips on removal or what would be best because either way she's gotta go and will be way too close for comfort! Thanks in advance!


I’d guess it’s Latrodectus mactans, although L. variolus can also be found in your state.


Where is she set up relative to the places that your kids occupy? She has her web set up so she is unlikely to move. What I would advice is just exercising care in that area. The only way someone would get bit is by mistakenly grabbing her. Overall it is a good lesson for your kids. Respect nature and learn to exercise care in places where it inhabits.

Reactions: Agree 2


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## Ungoliant

NYAN said:


> Where is she set up relative to the places that your kids occupy? She has her web set up so she is unlikely to move. What I would advice is just exercising care in that area. The only way someone would get bit is by mistakenly grabbing her. Overall it is a good lesson for your kids. Respect nature and learn to exercise care in places where it inhabits.


With the invasive brown widows having taken over our state, it's nice to see a native black widow.

Reactions: Agree 2


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## TwitchingShark

So, I got bit by a widow about a year ago. It was not an enjoyable experience. By the time the ER doctor got to me all my muscles were seized. They gave me a shot of something and within 30 minutes or so I was back to normal. The next day I felt like I got hit by a train. 

Black Widows are fun to watch, but be cautious of their very strong venom.  I've had kidney stones, broken bones, spinal taps. That little bite was the worst by far!

In Oklahoma by the way. I've been seeing a lot more around my house over the past 3 years.


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## dangerforceidle

TwitchingShark said:


> So, I got bit by a widow about a year ago. It was not an enjoyable experience. By the time the ER doctor got to me all my muscles were seized. They gave me a shot of something and within 30 minutes or so I was back to normal. The next day I felt like I got hit by a train.
> 
> Black Widows are fun to watch, but be cautious of their very strong venom.  I've had kidney stones, broken bones, spinal taps. That little bite was the worst by far!
> 
> In Oklahoma by the way. I've been seeing a lot more around my house over the past 3 years.


Worse than kidney stones!  General consensus is that passing kidney stones is pretty high up on the pain index, so the bite must have been something.


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## chloeeeyo

So I was cleaning and I found a dead spider. At first I thought it was just a black widow so I wasn't freaked out but now I'm thinking it's a Redback and I'm totally freaking out. What do you guys think?
It's pretty small. about the size of a piece of cat food


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## Ferrachi

It could either be a L variolus or L Mactans depending on your location


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## pannaking22

@chloeeeyo not a redback, likely a southern widow, _L. mactans_


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## NYAN

Latrodectus mactans.

I wish people would read the thread before posting the exact same thing as the last person.


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## ReignofInvertebrates

chloeeeyo said:


> So I was cleaning and I found a dead spider. At first I thought it was just a black widow so I wasn't freaked out but now I'm thinking it's a Redback and I'm totally freaking out. What do you guys think?
> It's pretty small. about the size of a piece of cat food


Location helps to distinguish between Latrodectus spp. I don’t think it’s hasselti, but to be fair their toxicity levels are pretty similar so it doesn’t make much of a difference if that’s what you’re concerned about.


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## Stainlesssteelrat

I have noticed multiple examples of widows with red stripes down the back. I’d like to know what is the distinguishing feature that separates the red back from other widows?  Multiple locations. I do pest control around industrial sites and run across many widows in bait boxes meant for mice. The majority of the sites are in eastern Washington which is a widow heaven. I can usually determine spider families by webbing. But I have ran across multiple instances of spiders with red stripes on the back and was wondering what is the distinguishing feature.

Reactions: Sad 1


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## NYAN

Stainlesssteelrat said:


> I have noticed multiple examples of widows with red stripes down the back. I’d like to know what is the distinguishing feature that separates the red back from other widows?  Multiple locations. I do pest control around industrial sites and run across many widows in bait boxes meant for mice. The majority of the sites are in eastern Washington which is a widow heaven. I can usually determine spider families by webbing. But I have ran across multiple instances of spiders with red stripes on the back and was wondering what is the distinguishing feature.


These are all L. hesperus juvenile females. All North American black widow species have red markings besides an hourglass at some point in their life. The distinguishing factor here is range. You will probably never see an exotic widow species outside of its range unless it was transported. The habitat that you are seeing them in is not one where an exotic species would likely appear

Reactions: Agree 1


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## darkness975

The Snark said:


> If it's like @Smokehound714 says all over I suspect it will be like the Himalayan blackberry invasion in the pacific northwest. Essentially, obvious plans to take over the planet. However, environmental limiting factors came into play. So Geos prefer human habitation and are displacing Hesperus. But Hesperus has a huge range and widely differing environments. From the cold and constantly damp pacific northwest to the alkali flats on borders of death valley and south past the Salton Seat into Mexico. Opportunity invasives rarely are able to tolerate all the niches that the local animal populations have adapted to.


I hope that's true.


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## Ungoliant

Stainlesssteelrat said:


> I have noticed multiple examples of widows with red stripes down the back. I’d like to know what is the distinguishing feature that separates the red back from other widows?  Multiple locations. I do pest control around industrial sites and run across many widows in bait boxes meant for mice. The majority of the sites are in eastern Washington which is a widow heaven. I can usually determine spider families by webbing. But I have ran across multiple instances of spiders with red stripes on the back and was wondering what is the distinguishing feature.


It is common for juvenile black widows (of all species) to have red markings on their backs.  Most native species outgrow these markings, although red spots often remain on _Latrodectus variolus_ (the northern black widow).

Though you're unlikely to find them in Washington, _L. variolus_ can be distinguished from _L. hasselti_ (the redback spider) by the fact that _L. variolus_ has a broken hourglass under her abdomen.  (_L. hasselti_ has a solid hourglass.)

Otherwise, range is generally the easiest way to rule out _L. variolus_.  In North America, if you see a black widow with a red stripe, it's almost certainly one of our native widows (_L. hesperus_ in your state).  With global commerce, it's always _possible_ for a species to be introduced from another continent, but as far as I know, we have no documented redback populations in the U.S.


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## SolarArachnophobia

So I live in South TX and lately I’ve found two spiders that I’ve never really seen before in my house. (Two separate occasions) At first I thought they were black widows, but I’ve seen an one before and this one looks different from a black widow. So can someone help identify it? I wouldn’t want my siblings or dogs to get bitten and it be venomous. (ps i found the spider next to an also already dead scorpion recently)


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## Albireo Wulfbooper

SolarArachnophobia said:


> So I live in South TX and lately I’ve found two spiders that I’ve never really seen before in my house. (Two separate occasions) At first I thought they were black widows, but I’ve seen an one before and this one looks different from a black widow. So can someone help identify it? I wouldn’t want my siblings or dogs to get bitten and it be venomous. (ps i found the spider next to an also already dead scorpion recently)


This is definitely not a redback. It happens to have red on its back, but it's certainly not in the same family as redbacks. I'm nowhere near an expert on spiders in your area, but it appears to be a species in the _Castianeira _genus - these are harmless ground spiders. you can see a similar one here: https://www.whatsthatbug.com/2015/10/06/ground-spider-5/

Reactions: Agree 2


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## MarkB

Is this a red back and black widow hybrid?   On back porch in central Oklahoma.


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## Albireo Wulfbooper

MarkB said:


> Is this a red back and black widow hybrid?


That’s not a thing. Many of the native North American widow species have red markings on their dorsal side. I’ll let someone more versed in the US Latrodectus species give you an ID, but I am certain it will turn out to be a very normal local species.


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## MarkB

Albireo Wulfbooper said:


> That’s not a thing. Many of the native North American widow species have red markings on their dorsal side. I’ll let someone more versed in the US Latrodectus species give you an ID, but I am certain it will turn out to be a very normal local species.


OK thank you for the information.   I’m definitely not an expert.


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## MarkB

i thought the NA Black widow doesn’t have the orange stripe On the upper abdomen.


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## Albireo Wulfbooper

MarkB said:


> OK thank you for the information.   I’m definitely not an expert.


hey, me neither  thankfully we do have experts here and they’re generous with their knowledge!



MarkB said:


> i thought the NA Black widow doesn’t have the orange stripe On the upper abdomen.


There are several different species in North America that can have a variety of red or orange markings at different times in their lives - juveniles can look quite different from adults, for instance, and even within a given species there can be a range of different markings. I’ve seen a bunch of North American black widows that have similar markings to what’s in your photos, but I’m not familiar enough with them to hazard an ID.


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## dangerforceidle

In Oklahoma, all three native black widow species can be found: _Latrodectus hesperus_, _L. mactans_, and _L. variolus.  _As others have noted, all three native species can exhibit red markings along their dorsal side all the way through adulthood.

Reactions: Agree 1


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## Ungoliant

dangerforceidle said:


> In Oklahoma, all three native black widow species can be found: _Latrodectus hesperus_, _L. mactans_, and _L. variolus.  _As others have noted, all three native species can exhibit red markings along their dorsal side all the way through adulthood.


_L. variolus_ can likely be ruled out, as they typically have a broken hourglass.


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## JOinWV

Hi everyone, this is my first time on this forum. I found it while searching for information about the spider pictured here. I am a home inspector living in the eastern panhandle of WV. Found this one under the porch of a house in the woods. I'm finding a lot of confusing information about redback vs. widows, juveniles...etc. Anyone have a guess at this one?


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## Albireo Wulfbooper

JOinWV said:


> Hi everyone, this is my first time on this forum. I found it while searching for information about the spider pictured here. I am a home inspector living in the eastern panhandle of WV. Found this one under the porch of a house in the woods. I'm finding a lot of confusing information about redback vs. widows, juveniles...etc. Anyone have a guess at this one?
> View attachment 398652


In that region it’s most likely to be the northern widow, _Latrodectus variolus_.


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## t2jbird

Eh?


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## Albireo Wulfbooper

t2jbird said:


> Eh?
> View attachment 406116


Found in Kentucky? This could be either _L. mactans _(the southern black widow), or _L. variolus_ (the northern black widow). Both are native to that state, and I’m not good enough to tell the difference.


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## t2jbird

Albireo Wulfbooper said:


> Found in Kentucky? This could be either _L. mactans _(the southern black widow), or _L. variolus_ (the northern black widow). Both are native to that state, and I’m not good enough to tell the difference.


Yep. Google Lens told me Red Back and here I am lol


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## Albireo Wulfbooper

t2jbird said:


> Yep. Google Lens told me Red Back and here I am lol
> 
> 
> 
> 
> 
> 
> 
> 
> 
> View attachment 406122


Many Latrodectus species’ dorsal markings are highly variable, which makes them a poor candidate for identification by artificial intelligence. For some specimens, even experts would need to examine microscopic details to definitively discern between species. AI image interpretation is pretty good these days, but it’s very far from perfect, and it’s strongly limited by past input and by photo quality, angle, zoom level, lighting, etc. I like iNaturalist because it takes your location into account (which is a huge deal for arthropod identification), and because actual experts will provide corrections to identifications, often within days of uploading an image. Again, their AI is imperfect, but the experts on the platform make it so much better.

At any rate, you can rest assured that this  is certainly a native species and not a redback.

Reactions: Like 1


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## dangerforceidle

t2jbird said:


> Yep. Google Lens told me Red Back and here I am lol
> 
> 
> 
> 
> 
> 
> 
> 
> 
> View attachment 406122


Important to note, redbacks _are _widow spiders.  They belong to the same genus.  They just happen to have a different local common name than what they were called in North America.

_Latrodectus hasselti - _Australian redback
_Latrodectus mactans - _Southern black widow
_Latrodectus variolus _- Northern black widow

They are all cousins.  As @Albireo Wulfbooper pointed out, the North American species can retain their red dorsal stripe well into adulthood as well, redbacks just seem to keep it longer and more consistently.

The spider you found is certainly one of the two local species.

Reactions: Like 1


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## Bushidoren

I
I have seen these around here for 15 years. I finally  caught on to look at closely. This is in southern colorado in a hot arid area.


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## Widowman10

Hello fellow Coloradan! Classic hesperus!

Reactions: Like 1 | Agree 1


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## The Snark

How often does Hesperus retain the dorsal stripe into maturity?


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## Widowman10

The Snark said:


> How often does Hesperus retain the dorsal stripe into maturity?


Very rarely, it is variable by location/population, and it’s never nearly as pronounced as the hasselti. Whenever I’ve seen posts like these over the years it’s nearly always a picture of an immature female… I have seen some tiny hints of white carry into the adult stage of hesperus too, but again it’s rare and not pronounced.

Reactions: Agree 1 | Informative 1


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## darkness975

L mactans seems to be more prone to retaining some (or all) of the dorsal stripe.  At least in parts of its range.

Reactions: Informative 1


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