"Aren't tarantulas like, super poisonous?"

[JayDangerVL]

This was the question posed to me by a friend of mine at lunch the other day. I just stared at him, mouth agape for a second--it just blew my mind because this friend is usually so knowledgeable and doesn't ever make judgments without a proper source.

I was like, "Where did you get that from? Arachnophobic Phil?"

It's precisely these sorts of misconceptions that are the reasons why I can't keep a tarantula in a house with other people. I had to sit down with this boy and give him proper links to proper websites so he could determine with sorts of spiders are ACTUALLY dangerous, and which ones are less dangerous than keeping common household pets. He was surprised to find that for the most part, smaller varieties of spiders tend to be more venomous than bigger spiders. Is that at least, a conclusion we can agree on? That's a fact that seems to surprise most of my friends, actually. Even Australia's tiny Atrax robustus is far more aggressive and dangerous than their larger and more commonly intimidating Huntsman spiders.

 

[Stefan2209]

Even Australia's tiny Atrax robustus is far more aggressive and dangerous than their larger and more commonly intimidating Huntsman spiders.

Hi,

something in between...

There are just 5 genera known to be able to inflict potentially life-threatening symptoms in healthy adult humans with a bite:

1. Sicarius
2. Latrodectus
3. Loxosceles

4. Atrax/Hadronyche
5. Phoneutria

While your idea of "small spiders being the most toxic" may seem to fit for the first three mentioned genera, i'm personally rather reluctant to call some species of the latter "small".
While A. robustus is the most infamous species within the family Hexathelidae, its not the most venomous one and especially not the largest. If you dig into information about some of the even more toxic "tree funnel web spiders" from the genus Hadronyche, you will find that those are not only more toxic, but also quite larger.
Phoneutria can in some species (including the infamous and very venomous) attain body-sizes of 2" and leg-spans of something like 6-7" - don't know about your perception, but personally i wouldn't consider this "small" by any objective means.

Things may look different though, if you compare any mentioned genus / species to, for example, T. blondi as a reference - so its really mostly a matter of perception and what you or the person you're speaking to is considering to be "large".

Take care,

Stefan

 

[Beary Strange]

Hi,

something in between...

There are just 5 genera known to be able to inflict potentially life-threatening symptoms in healthy adult humans with a bite:

1. Sicarius
2. Latrodectus
3. Loxosceles

4. Atrax/Hadronyche
5. Phoneutria

While your idea of "small spiders being the most toxic" may seem to fit for the first three mentioned genera, i'm personally rather reluctant to call some species of the latter "small".
While A. robustus is the most infamous species within the family Hexathelidae, its not the most venomous one and especially not the largest. If you dig into information about some of the even more toxic "tree funnel web spiders" from the genus Hadronyche, you will find that those are not only more toxic, but also quite larger.
Phoneutria can in some species (including the infamous and very venomous) attain body-sizes of 2" and leg-spans of something like 6-7" - don't know about your perception, but personally i wouldn't consider this "small" by any objective means.

Things may look different though, if you compare any mentioned genus / species to, for example, T. blondi as a reference - so its really mostly a matter of perception and what you or the person you're speaking to is considering to be "large".

Take care,

Stefan

+1

See, by saying " smaller spiders are more dangerous" you're essentially adding fuel to the fire that is nonsensical spider myths. I had a co-worket today (who is charmingly fascinated by my little ones) ask "Aren't jumpers really poisonous and huge?". I explained that no, they generally don't bite and if they did the bite would be insignificant, and showed her using my thumbnail as a rough estimate of their size. She seemed very surprised.
I always make a point to explain to people who come up to me to ask questions that there are very few spiders capable of causing them any harm and that most of those don't even reside in the US.

 

[JayDangerVL]

Hi,

something in between...

There are just 5 genera known to be able to inflict potentially life-threatening symptoms in healthy adult humans with a bite:

1. Sicarius
2. Latrodectus
3. Loxosceles

4. Atrax/Hadronyche
5. Phoneutria

While your idea of "small spiders being the most toxic" may seem to fit for the first three mentioned genera, i'm personally rather reluctant to call some species of the latter "small".
While A. robustus is the most infamous species within the family Hexathelidae, its not the most venomous one and especially not the largest. If you dig into information about some of the even more toxic "tree funnel web spiders" from the genus Hadronyche, you will find that those are not only more toxic, but also quite larger.
Phoneutria can in some species (including the infamous and very venomous) attain body-sizes of 2" and leg-spans of something like 6-7" - don't know about your perception, but personally i wouldn't consider this "small" by any objective means.

Things may look different though, if you compare any mentioned genus / species to, for example, T. blondi as a reference - so its really mostly a matter of perception and what you or the person you're speaking to is considering to be "large".

Take care,

Stefan

+1

See, by saying " smaller spiders are more dangerous" you're essentially adding fuel to the fire that is nonsensical spider myths. I had a co-worket today (who is charmingly fascinated by my little ones) ask "Aren't jumpers really poisonous and huge?". I explained that no, they generally don't bite and if they did the bite would be insignificant, and showed her using my thumbnail as a rough estimate of their size. She seemed very surprised.
I always make a point to explain to people who come up to me to ask questions that there are very few spiders capable of causing them any harm and that most of those don't even reside in the US.

This is exactly the sort of insight I was looking for from this website. I hope you don't mind if I print this off and give it to my friend for his information.

For discussion's sake, though, would you say that Phoneutria and Atrax/Hadronyche are considered "small" in comparison to the other spiders found in the area? And for the jumpers, would you say that jumpers are larger in comparison to the other spiders found in the immediate area? Of course grass spiders can get larger than jumpers, but their bites aren't terribly fatal either.

 

[Beary Strange]

This is exactly the sort of insight I was looking for from this website. I hope you don't mind if I print this off and give it to my friend for his information.

For discussion's sake, though, would you say that Phoneutria and Atrax/Hadronyche are considered "small" in comparison to the other spiders found in the area? And for the jumpers, would you say that jumpers are larger in comparison to the other spiders found in the immediate area? Of course grass spiders can get larger than jumpers, but their bites aren't terribly fatal either.

I can't answer from experience with Atrax or Phoneutria, as I have not kept either. I can tell you that I have often heard that Phoneutria are commonly mistaken for Theraphosids, and if Stefan's post above is anything to go by, at 6-7" DLS I can see why. And you can probably agree that 6-7" DLS is nothing to scoff at.
As far as jumpers go, there are a variety of species and some are quite teeny, but the common ones the average person will ever come across in the US are larger than the average house spider yes, and thus when a normal person sees one they think this "huge" spider must be super venomous and want their soul. Of course, as anyone with experience with them knows, this is absolute nonsense.
You could try referring your friend to this website:
http://www.burkemuseum.org/spidermyth/index.html
It also makes for an interesting read. I never had any idea some people think things like "All spiders are male". People are bizarre. o.o

 

[The Snark]

Atrax: 1 to 5 cm body length, leg span up to 15 cm. Small, compared to your average horse.

 

[Smokehound714]

Actually, that's pretty impressive for a non theraphosid myg. Most do not reach a 5 cm body length, even the generally larger species like bothriocyrtum, aptostichus, and ummidia, 5 cm is quite large- a two inch body length. I had no idea atrax got so huge. I want one really bad now.

 

[JayDangerVL]

I can't answer from experience with Atrax or Phoneutria, as I have not kept either. I can tell you that I have often heard that Phoneutria are commonly mistaken for Theraphosids, and if Stefan's post above is anything to go by, at 6-7" DLS I can see why. And you can probably agree that 6-7" DLS is nothing to scoff at.
As far as jumpers go, there are a variety of species and some are quite teeny, but the common ones the average person will ever come across in the US are larger than the average house spider yes, and thus when a normal person sees one they think this "huge" spider must be super venomous and want their soul. Of course, as anyone with experience with them knows, this is absolute nonsense.
You could try referring your friend to this website:
http://www.burkemuseum.org/spidermyth/index.html
It also makes for an interesting read. I never had any idea some people think things like "All spiders are male". People are bizarre. o.o

Atrax: 1 to 5 cm body length, leg span up to 15 cm. Small, compared to your average horse.

Horses are pretty venomous, I hear.

Actually I did just do some reading up on Phoneutria just now, and yeah, it looks like those bad boys can get pretty large! About the size of my hand! I would by no means, call that small. Touche and many thanks, Mister Stefan. I shall inform my friend immediately.

 

[The Snark]

OP, it sounds like somewhere along the line the venom toxicity got mixed up with delivery mechanism a little bit. Anyway, size has no bearing on potency of the venom but it does aid in delivering it. There are basically three common factors when it comes to humans getting bit and suffering significant illness. Venom potency, ability to deliver it, and proximity to humans. All three must be taken into account. The widow presents a significant hazard with a very powerful venom and they are commonly found in human habitations. But their delivery mechanism is pretty sucky and they can't be accused of being a bold fearless predator. Phoneutria. the cause of the vast majority of illness from spider bites, has the venom and delivery mechanism down pat and they range over wide areas which often include human habitation. Atrax is similar to Phoneutria with the limitation they usually only come in contact with humans when the males get to feeling romantic and go out for a stroll. As for the rest of the significant spider bites, they are very rare and almost always accidental. All the factors just happened to jive when human put it's anatomy in just the wrong place.

 

[viper69]

And for the jumpers, would you say that jumpers are larger in comparison to the other spiders found in the immediate area? Of course grass spiders can get larger than jumpers, but their bites aren't terribly fatal either.

IMO, jumping spiders are actually quite small particularly when you include legspan as part of one's definition of "large/small" in comparison to other spiders. In fact, while jumpers are my favorite spiders, they often go overlooked because they are hard to see. However, if you google something like Largest Jumping Spider, there's a cool video on YouTube of someone having one on their wrist or arm. Anyway, it's REALLY large for a jumper!

 

[JayDangerVL]

OP, it sounds like somewhere along the line the venom toxicity got mixed up with delivery mechanism a little bit. Anyway, size has no bearing on potency of the venom but it does aid in delivering it. There are basically three common factors when it comes to humans getting bit and suffering significant illness. Venom potency, ability to deliver it, and proximity to humans. All three must be taken into account. The widow presents a significant hazard with a very powerful venom and they are commonly found in human habitations. But their delivery mechanism is pretty sucky and they can't be accused of being a bold fearless predator. Phoneutria. the cause of the vast majority of illness from spider bites, has the venom and delivery mechanism down pat and they range over wide areas which often include human habitation. Atrax is similar to Phoneutria with the limitation they usually only come in contact with humans when the males get to feeling romantic and go out for a stroll. As for the rest of the significant spider bites, they are very rare and almost always accidental. All the factors just happened to jive when human put it's anatomy in just the wrong place.

This is a really helpful explanation, which explains some of the thought behind my original theory, but also debunks some of it and offers better reasoning. Thank you. About the Black Widow a bit though--I don't know a whole lot about that species and all I have to go on that one is what I've heard. When you say their delivery mechanism is sucky, what do you mean? Like, the fangs can't pierce the skin? Or what? But that can't be right... otherwise there wouldn't be reports of fatal incidents. ARE there even reports of fatal incidents? What am I hearing wrong here?

IMO, jumping spiders are actually quite small particularly when you include legspan as part of one's definition of "large/small" in comparison to other spiders. In fact, while jumpers are my favorite spiders, they often go overlooked because they are hard to see. However, if you google something like Largest Jumping Spider, there's a cool video on YouTube of someone having one on their wrist or arm. Anyway, it's REALLY large for a jumper!

Jumpers are my favorites too. I'm so sad it's cold out now, because I can't find any anymore. Legspan DOES make a difference... maybe I should be looking at variety of spider (funnel-weavers, ground spiders, cobweb spiders, jumpers) instead of size? Is there a simple pattern to this toxicity thing? Or is it all relative?

I'll have to check out that video of largest jumper.

---------- Post added 11-10-2013 at 10:59 AM ----------

I can't answer from experience with Atrax or Phoneutria, as I have not kept either. I can tell you that I have often heard that Phoneutria are commonly mistaken for Theraphosids, and if Stefan's post above is anything to go by, at 6-7" DLS I can see why. And you can probably agree that 6-7" DLS is nothing to scoff at.
As far as jumpers go, there are a variety of species and some are quite teeny, but the common ones the average person will ever come across in the US are larger than the average house spider yes, and thus when a normal person sees one they think this "huge" spider must be super venomous and want their soul. Of course, as anyone with experience with them knows, this is absolute nonsense.
You could try referring your friend to this website:
http://www.burkemuseum.org/spidermyth/index.html
It also makes for an interesting read. I never had any idea some people think things like "All spiders are male". People are bizarre. o.o

Hey this website is great! XD Thanks for sharing it! I'm going to be reading it all day! (And yeah, I bet my friend will get a kick out of it too--thanks again!)

 

[viper69]

Like, the fangs can't pierce the skin? Or what? But that can't be right... otherwise there wouldn't be reports of fatal incidents. ARE there even reports of fatal incidents? What am I hearing wrong here?

Jay I think your curiosity is cool, but I also think you need you read up before saying the above haha. It isn't that you aren't hearing, I think you aren't calling your friends at google and finding out some answers to the very simply question you asked here hahah. I mean c'mon man, if their fangs couldn't pierce how could people die because of them??? Black Widows have a 5% mortality rate. They venom is ~15 times more potent than a rattlesnakes if I recall correctly. If you have a real interest in venom, then you need to look up the term LD50.

Regarding size of animal and venom, where do you come up with these crazy ideas hahaha. There is absolutely ZERO correlation to size of animal and venom toxicity. If you take all of the poisonous animals in the world, the most toxic animal is also the smallest, (yes it KILLS, before you ask). I've talked to scientists that research this animal, and they have only theories as to why its so poisonous, but the truth is they have absolutely no idea as the scientist told me.

When it comes to toxins, what does exist, is that certain toxins produced by a variety of different animals are often related, not just related by their function (eg neurotoxin), but also related by the protein's physical structure too (eg ICK knot toxins)

 

[BobGrill]

Never understood the fear of widows to be honest.

 

[viper69]

Never understood the fear of widows to be honest.

Really why is that? You don't think a 5% mortality rate is something that generates fear or concern for most people, what's not to understand? haha

I know the species in N. America is relatively shy actually. And I had 2 "living" with me. One in a closet (that lasted 2 days), and one really pesky one at the doorstep. Craziest looking web I've seen, every time I tried to get her, right down between the house and the doorstep apt slab. I could never get her. I will say they sure appear to be clumsy walkers when they aren't in their web, unlike some other spiders.

 

[akarikuragi]

I can understand the fear of widows but I don't think it's necessarily warranted. Car accidents kill thousands of people every year but few people think twice about getting into their cars. And, from my understanding of it, the odds of a healthy adult dying from a widow bite is much less than that of a child or elderly person.

As to the original topic, I think people see big spiders and they automatically think dangerous, but that is often not the case. And while speaking in absolutes often leads to false information, isn't is safe to say that most large spiders aren't dangerous to the point of life threatening? And by large I mean average tarantula size and up. Just because there are more dangerous spiders on the small side than the large side doesn't mean that all small spiders are dangerous. I think what the OP was trying to communicate with their friend is that big =/= dangerous, and that there are lots of dangerous small spiders as well.

 

[JayDangerVL]

Jay I think your curiosity is cool, but I also think you need you read up before saying the above haha. It isn't that you aren't hearing, I think you aren't calling your friends at google and finding out some answers to the very simply question you asked here hahah. I mean c'mon man, if their fangs couldn't pierce how could people die because of them??? Black Widows have a 5% mortality rate. They venom is ~15 times more potent than a rattlesnakes if I recall correctly. If you have a real interest in venom, then you need to look up the term LD50.

This is precisely what I'm saying and why I'm here--I keep hearing different things from different sources. The problem isn't that I'm not reading up, the problem is that I'm getting inconsistent information, I'm confused, and I'm not understanding some of the things that are being said to me. Are you criticizing me for asking questions? Because I have zero facts here--only inquiries and disproved hypotheses. If black widows have a 5% mortality rate, then obviously they can kill. And yet I'm told their mechanism for delivering the venom is sub-par? Well what does that mean? That the venom can't penetrate the skin? That can't be true, if people have died. Unless people are straight up extracting the toxins and then drinking it out of a cup--but I find that unlikely. Though perhaps that is another of my ill-formed assumptions. So how exactly is the venom delivered, and what about it makes it ineffective as a delivery mechanism, especially if there IS a mortality rate?

And for the third time, I think it's pretty clear by now that my initial theory was inaccurate, and the size of the spider really has nothing to do with the potency of the venom. That's good, because now I know, and I can make more informed statements in the future. Now I also know that different kinds of venom can have different effects, so that's pretty cool to know too.

But unless anyone has any helpful links to venom studies or anything like that, I'm still at a partial loss here. (Thanks for all your help, though... I know communicating such complex ideas to someone with no knowledge of the subject can be frustrating.)

---------- Post added 11-10-2013 at 05:13 PM ----------

I can understand the fear of widows but I don't think it's necessarily warranted. Car accidents kill thousands of people every year but few people think twice about getting into their cars. And, from my understanding of it, the odds of a healthy adult dying from a widow bite is much less than that of a child or elderly person.

As to the original topic, I think people see big spiders and they automatically think dangerous, but that is often not the case. And while speaking in absolutes often leads to false information, isn't is safe to say that most large spiders aren't dangerous to the point of life threatening? And by large I mean average tarantula size and up. Just because there are more dangerous spiders on the small side than the large side doesn't mean that all small spiders are dangerous. I think what the OP was trying to communicate with their friend is that big =/= dangerous, and that there are lots of dangerous small spiders as well.

Thank you--but the actual statement was indeed, "Smaller spiders tend to be more venomous, and larger spiders less so." That on its own is a pretty unspecific statement, so I think most of the criticism here is rightfully earned--because I even knew that there were plenty of low/zero toxicity itty bitty spiders out there, depending on your definition of "itty bitty". But yeah, I was mostly just appalled that he would even say such a thing without the proper research, and here I am doing the exact same thing! Anyway, I'm glad I came to Arachnoboards to clear up my misunderstanding. I try to look things up for myself, but let's face it! I know very little on the subject and I can't seem to come across good sources. I find the people here, who have had more experience, are a bit more helpful than a general Google search.

Thanks again!

 

[viper69]

I can understand the fear of widows but I don't think it's necessarily warranted. Car accidents kill thousands of people every year but few people think twice about getting into their cars. And, from my understanding of it, the odds of a healthy adult dying from a widow bite is much less than that of a child or elderly person.

True on both. More likely to die in a car, in fact I read once that driving is the most dangerous/lethal activity that people do. I think it comes down to needs and other human centric thoughts. Most people need to drive a car, or enter a car, plus they feel in control when driving, "it won't happen to me" etc etc.

But no one needs to have a Black Widow spider living in their house or in their immediate vicinity where they have the potential to be bitten. It reminds me about people's fear of sharks...anyway............

---------- Post added 11-10-2013 at 02:50 PM ----------

This is precisely what I'm saying and why I'm here--I keep hearing different things from different sources. The problem isn't that I'm not reading up, the problem is that I'm getting inconsistent information, I'm confused, and I'm not understanding some of the things that are being said to me. Are you criticizing me for asking questions? Because I have zero facts here--only inquiries and disproved hypotheses. If black widows have a 5% mortality rate, then obviously they can kill. And yet I'm told their mechanism for delivering the venom is sub-par? Well what does that mean? That the venom can't penetrate the skin? That can't be true, if people have died. Unless people are straight up extracting the toxins and then drinking it out of a cup--but I find that unlikely. Though perhaps that is another of my ill-formed assumptions. So how exactly is the venom delivered, and what about it makes it ineffective as a delivery mechanism, especially if there IS a mortality rate?

Jay..I don't know what you are hearing at all. As for Black Widow, this doc took me all but 1 minute to find via Google https://secure.uuhsc.utah.edu/poison/healthpros/utox/Vol4_No3.pdf

And another 10 seconds for this one http://www.cdc.gov/niosh/topics/spiders/

This is what I meant earlier that you are quite capable of finding your own links to many of the answers of your questions by calling your friends at Google. How hard is it to type "black widow mortality rates" into a google search box, hit enter, and look for reasonably good resource?? Finding reliable information isn't rocket science. Pretend you are writing a research paper and you, the writer, have to research it yourself using the available literature.

 

[BobGrill]

Really why is that? You don't think a 5% mortality rate is something that generates fear or concern for most people, what's not to understand? haha

I know the species in N. America is relatively shy actually. And I had 2 "living" with me. One in a closet (that lasted 2 days), and one really pesky one at the doorstep. Craziest looking web I've seen, every time I tried to get her, right down between the house and the doorstep apt slab. I could never get her. I will say they sure appear to be clumsy walkers when they aren't in their web, unlike some other spiders.

I honestly would take any type of widow over any of the Australian funnel webs or the Brazilian wandering spider. Widows are like kittens compared to those spiders

 

[The Snark]

http://en.wikipedia.org/wiki/Spider_bite
Scroll down to the chart. It appears to be quite accurate with lots of references and citations.

Black widow bites had a 5% death rate prior to antivenin. It's really hard for a widow to compete with the big fast hunting and roaming spiders when they tend to run into a little hole and hide when their web gets bumped. Then their fangs are quite small so most of reported illness and deaths are from multiple bites where the animal got trapped against the skin.

 

[viper69]

I honestly would take any type of widow over any of the Australian funnel webs or the Brazilian wandering spider. Widows are like kittens compared to those spiders

Hahah man, cmon Bob. Do you even THINK the average person in N. America has heard of either of those??? Some don't even know what a Brown Recluse is. It's all relative Bob =P

Speaking of Black Widow's there a pharma company that has clinical trial going on right now for a new antivenom against BW's venom, it's supposedly much better than the current antivenom.