Which's more venomous...a Black Widow or a Poecilotheria?

[Vayu Son]

><

So what your saying is NW sucks and Australia has it coming?

-V

 

[skadiwolf]

doesn't knowing more about the world's most venomous spiders just help you guys sleep better at night?

(looks around nervously) um, i'm not sure about me...

really though, that's just fascinating stuff. any kind of truly dangerous, 'hot' animal is one that i'd rather not see kept in captivity.

i admire them sure, but from aFAR. they just seem to post such a huge risk to their owners and those around them.

(sigh) i wish it wasn't so easy to own hots. :/

 

[Steve Nunn]

Re: ><

Originally posted by Vayu Son
So what your saying is NW sucks and Australia has it coming?

-V

Nahhh, NW rules in a harmless kind of way

 

[Venom]

How would you rate Loxosceles leata, which has a very high incidence of systemic affects ( viscerocutaneus loxoscelism ), from which deaths are not too uncommon, taking into account its size, aggression, and its abundance in populated areas?

 

[Vayu Son]

><

I think i can field this one. Genera Loxosceles, while certainly dangerous due to its living in close proximity to south american populations, does not come close to being the most venomous. Its danger is also overated, since most if not all recluse bites come from accidentally stepping on or inadvertently crushing the spider. Compare that to the little demons in australia and what we have is the cupcake spider trio

In fact, I recently spoke with Dr.Robert Gale Breene III, who informed me that a 1.0 mg/hr nitro-glycerine patch applied to the surface of the bite should counter Loxosceles venom effectively.

-V

 

[Steve Nunn]

Originally posted by Venom
How would you rate Loxosceles leata, which has a very high incidence of systemic affects ( viscerocutaneus loxoscelism ), from which deaths are not too uncommon, taking into account its size, aggression, and its abundance in populated areas?

Hi Venom,
Loxosceles laeta is reported to be the most venomous of the Loxosceles spp. Loxoscelism is too fancy a word, necrosis says it all, and the fact that many spiders can cause necrosis kind of makes the term 'loxoscelism' irrelevant. Also, the necrosis has recently been found to originate from bacteria found on the fangs, bacteria from certain prey items. The venom has no necrotic components whatsoever. This bacteria can be found in many of the Salticidae, Lycosidae and gnaphosidae spp. who have also been shown to 'spread' necrosis through bites.

No substantiated deaths from this species either as far as I know. The bite can be effectively treated with ease.

All that said, there's a few factors that throw this particular species into the spotlight. They're inhabiting Florida now aren't they? They are obviously hardy spiders who can survive outside their original habitat and may spread further, giving them some serious thought on a most dangerous list, if one is even possible to make. I'd still say, like most of the Loxosceles spp., they are probably overrated in terms of aggression and venom potency. Still, not a spider to get bitten by...

Cheers,
Steve

 

[Steve Nunn]

Re: ><

Oops, my apology VS, you beat me to it.

 

[Venom]

Actually, there have been deaths from L. leata, and what I meant by "systemic loxoscelism" was the affects of the bite other than local necrosis. Loxosceles venom has in fact been analyzed as containing several enzymes that cause the necrosis. You should visit these websites:

http://www.emedicine.com/EMERG/topic547.htm

http://www.maripoisoncenter.com/ctr/9908brspider.html


One is from a medical website, and the other is a toxicological review.

And on the Phoneutria sp. , some venom potency data is available here:

http://www.sciencenet.org.uk/database/Biology/9612/b00686d.html

 

[invertepet]

Although I'm sure Latrodectus has a higher LD50, I'd rather get bitten by a Widow than a Poecilotheria. Much less venom, less chance of a heavy envenomation and just about every Poec bite report I've seen involves severe cramping, nausea, dizziness and general bad things including muscle spasms for days, with the residual spasms and stiffness lasting weeks or more. No thanks.

Many L. mactans and hesperus bites I've heard of go without much in the way of problems because there's antivenom that can be administered. Not so with Poecilotheria. Can you imagine telling the EMT that you were bitten by a rare Indian arboreal tarantula? I had a hard enough time getting the shift nurse to understand that I was stung by C. exilicauda, not one of the local harmless U. mordax.

"But those don't live around here..." she kept saying.



bill

 

[Steve Nunn]

Originally posted by Venom
Actually, there have been deaths from L. leata, and what I meant by "systemic loxoscelism" was the affects of the bite other than local necrosis. Loxosceles venom has in fact been analyzed as containing several enzymes that cause the necrosis. You should visit these websites:

Is this where you sourced your info? I still don't believe there is one single confirmed fatality from any Loxocseles sp. Any other info to back up the fatality thing? The site on the wanderer is interesting, considering not one single spider is "poisonous". Most are venomous, but not poisonous as the site wrongly suggests.

The information on necrotic enzymes found in Loxosceles venom has me intrigued too. I found out from Dr Raven last year that after much research it had been confirmed and published that the necrotic components found in recluse venom (and numerous other species) actually came from bacteria found on the fangs. I'm wondering what is up. Prior to this discovery, it was shown that the venom harboured the necrotic enzymes (due to the way the venom is extracted), which was indeed wrong.
I'm not saying your information is incorrect, just that I've heard otherwise from very reputable sources.

Cheers,
Steve

 

[Venom]

Is this where you sourced your info?

>>I had most of the info kicking around in my head already, I just >>wanted some sites as support for my statements.

I still don't believe there is one single confirmed fatality from any Loxocseles sp. Any other info to back up the fatality thing?

>>I'll see if I can find some reliable death stats on Loxosceles.

The site on the wanderer is interesting, considering not one single spider is "poisonous". Most are venomous, but not poisonous as the site wrongly suggests.


>> ( I think they meant "venomous", but used the term "poisonous" because they didn't know the different there was a difference.)

The information on necrotic enzymes found in Loxosceles venom has me intrigued too....I'm not saying your information is incorrect, just that I've heard otherwise from very reputable sources.

>> Hmm, ok. I don't know then. You'd think whoever analyzed the venom could tell the difference between bacterial enzymes, and arachnid venom. Are you sure you're not thinking about the white-tailed spider ( Lampona sp. )? I read that it's necroses were possibly bacterial in origin- again, from bacteria on the spiders' chelicera. Did you get Loxosceles and Lampona mixed up, or were the analyses of Dr. Raven actually for the recluse spiders? This is an interesting enigma. Again, I'll see what info I can find on this.

 

[Steve Nunn]

Originally posted by Venom
>>I'll see if I can find some reliable death stats on Loxosceles.

Good luck From what I can ascertain, most paperwork on the recluses mentions deaths involved, but not one report is substantiated. If you can find one confirmed death, I know of at least two pro taxonomists who'll want to know.

>> ( I think they meant "venomous", but used the term "poisonous" because they didn't know the different there was a difference.)

And that's why I wouldn't hold any weight to that sites info....It could be called petty, but when dealing with such medical issues the correct terminology is fairly important, no? And if that can be overlooked how correct is their info going to be?

You'd think whoever analyzed the venom could tell the difference between bacterial enzymes, and arachnid venom. Are you sure you're not thinking about the white-tailed spider ( Lampona sp. )? I read that it's necroses were possibly bacterial in origin- again, from bacteria on the spiders' chelicera. Did you get Loxosceles and Lampona mixed up, or were the analyses of Dr. Raven actually for the recluse spiders?

The work was carried out by a few more people then Raven, although he was involved. The study wasn't just on L.cylindrata but coverd the families Clubionidae, Miturgidae,Gnaphosidae, Lycosidae and Salticidae. All members of these families were capable of causing necrotic arachnidism in humans. I KNOW the results for all these families showed that bacteria caused the necrosis, and it was hypothesized that the bacteria came from a particular prey item. Because these spiders are all rovers it's believed the prey item is a ground crawler (no web spinners can cause necrosis). What I will find out is if the family Loxoscelidae was also involved in the study.

Maybe you are correct. I would find it highly unlikely though due to the fact that it was once thought that the necrosis from all these families originated from the venom. Maybe it is a coincidence that Loxosceles actually produces it's own necrotic components while all these other families just as capable of giving the same dermal necrotic arachnidism just happen to possess bacteria that performs the exact same task. It would also then be another coincidence that Loxoscelidae hunt in the exact same fashion as the above mentioned families, giving them access to the same prey items. I would strongly doubt it, but, anything is possible.

Cheers,
Steve

 

[invertepet]

Someone drag Spider Bob in here - he can shed much light on Loxosceles venom toxicity & history.

bill

 

[belewfripp]

Re: Re: ><

Originally posted by Steve Nunn
Nahhh, NW rules in a harmless kind of way

If someone told me that, in truth, koala bears carry sniper rifles and enjoy picking off tourists from a distance, i don't think it'd surprise me in the least.

Adrian

 

[Steve Nunn]

Re: Re: Re: ><

Originally posted by belewfripp
If someone told me that, in truth, koala bears carry sniper rifles and enjoy picking off tourists from a distance, i don't think it'd surprise me in the least.

Adrian

You haven't heard the stories of the Drop Bears, have you??

 

[Vayu Son]

><

I have. What the hell are they, malicious tree kangaroos?

-V

 

[Steve Nunn]

Originally posted by invertepet
Someone drag Spider Bob in here -

Too true Bill, does the hairy old codger post here???

 

[Venom]

Let's say that you are correct, and that Loxoscelidae cause necrotism only as a result of bacteria. How then would you explain the systemic affects of their bite? Also, you say that no webspinning spider can cause necrotism. What about the hobo spider ( Tegeneria agrestis )? It has definitely caused necrotism, and yet it is an Agelenid funnel weaver. The necrotism of this species has been confirmed by an arachnologist, Darwin Vest.

To quote Vest : "The lesion that results is sometimes oblong or multiple, resulting not from more than one spider bite, but rather from gravitational drift, which moves venom components downward, away from the bite site. The process which causes the local phenomenon of necrotic arachnidism involves circulatory disturbances which result in ischemia, or lack of adequate blood flow in the affected tissues. Following venom injection, rapid coagulation of blood occurs in the smaller blood vessels of these tissues. This produces a centralized area which does not receive enough blood, and the area literally dies as a result of oxygen starvation."

To me, that seems inconsistent with a bacterial infection.

 

[SurfinJB]

Just thought this might interest some of you-- I live in Fl and was bitten by a Black Widow at the age of 6. They were very common in my area as I lived in a house bordering the Ocala National Forrest. At the bite site(the joint of my middle finger) a boil started to develop on my hand. It got quite large the size of a quarter. I don't really remember every detail I'm 25 now, but the vein running right by the middle finger joint in my arm turned a bight reddish color and started to work its way up my arm. At this point I was rushed to the family doctor who said it was definetly a Black Widow bite and that was the venom traveling up my arm and if it were to reach my heart I would've been in trouble. I was feeling ok so I didn't recieve any shots, but they started soaking my hand in something and I had to keep a really hot washcloth on it which seemed to stop the red veins at my lower shoulder. The veins reddness slowly receeded over the next few days back to the bite site. I don't remember feeling the actual bite , or maybe I did and assumed it was a deer fly. My 9th grade teacher who was around 24 at the time wasn't so lucky. He didn't feel the bite either- he was ridding a bike throught the woods. He was bitten in the back of the neck and became violently ill. He was in the hospital for a 2 day stay and made a full recovery, but it was a close call for him. ED: forgot to metion I still have the scar.

 

[Steve Nunn]

Venom, I don't have all the answers, I'm just posting what was relayed to me from Raven himself. The hobo has access to the exact same prey that might be encountered by the rovers, it's as simple as that, when I mentioned web spinners, I should have been more specific, so as not to seem tripped up if you will.

Here's Raven's email address, he may respond to your questions and I'm sure he'd do a damn sight better job then me, I just keep tarantulas, what do I know???

Raven: RobertR@qldmus.gov.au

Cheers,
Steve