Spider question
Discussion
My googling skills aren't up to finding an answer to this, so I thought I'd try PH.
Why is it that black widow spiders have such a poisonous venom? They're so tiny that their idea of a blow out meal is probably a fly the size of a shirt button, so why on earth do they need poison that is so toxic it can kill a human?
Why is it that black widow spiders have such a poisonous venom? They're so tiny that their idea of a blow out meal is probably a fly the size of a shirt button, so why on earth do they need poison that is so toxic it can kill a human?
I'm no expert, although my dad is an entomolgist, and some knowledge rubbed off.
Generally, really poisonous animals don't need to be big to win a fight. Look at scorpions, the smaller ones are more poisonous, and the larger ones rely on brute strength / pincers.
Also, spiders often take quite large prey and spend a while sucking the juices
A fly might not be a blow out meal.
Thirdly, speed of death is a factor. The poison might be deadly enough to kill a human, but that's not the only point. the spider will want to incapacitate the prey quickly, so they have venom that is 'overkill' for want of a better word.
Wikipedia page on Black widows
Generally, really poisonous animals don't need to be big to win a fight. Look at scorpions, the smaller ones are more poisonous, and the larger ones rely on brute strength / pincers.
Also, spiders often take quite large prey and spend a while sucking the juices
A fly might not be a blow out meal. Thirdly, speed of death is a factor. The poison might be deadly enough to kill a human, but that's not the only point. the spider will want to incapacitate the prey quickly, so they have venom that is 'overkill' for want of a better word.
Wikipedia page on Black widows
wolves_wanderer said:
Maybe it's because they are quite delicate (legs etc) so they need to kill food instantly.
I thought of that, yes - but there are plenty of other small spiders that are equally as delicate that are harmless to humans. Plus, I would have thought that they'd simply evolve to be stronger. Genetic variations in strength must be more common than variations in venom toxicity, so evolution would favour making the spider stronger I would have thought.
Raify said:
I'm no expert, although my dad is an entomolgist, and some knowledge rubbed off.
Generally, really poisonous animals don't need to be big to win a fight. Look at scorpions, the smaller ones are more poisonous, and the larger ones rely on brute strength / pincers.
Also, spiders often take quite large prey and spend a while sucking the juices
Thirdly, speed of death is a factor. The poison might be deadly enough to kill a human, but that's not the only point. the spider will want to incapacitate the prey quickly, so they have venom that is 'overkill' for want of a better word.
Wikipedia page on Black widows
Thanks for your post. I see your point, but why have Black Widows evolved such toxic poison when other small spiders haven't? Is their diet really that different that they need it?
Is it true that some spiders in the uk are now developing fangs that are capable of delivering their poison to humans?
I have heard this a lot over the past couple of years, and based on the notion that most spiders have enough venom to be harmful to humans.....well, it's a bit
Over the last year or so, I've seen at least three spiders - all miles bigger than I've ever seen in my life before - at least the size of a 50p coin, and this is in the West coast of Scotland!
>> Edited by ApexClipper on Thursday 23 February 11:38
I have heard this a lot over the past couple of years, and based on the notion that most spiders have enough venom to be harmful to humans.....well, it's a bit
Over the last year or so, I've seen at least three spiders - all miles bigger than I've ever seen in my life before - at least the size of a 50p coin, and this is in the West coast of Scotland!
>> Edited by ApexClipper on Thursday 23 February 11:38
ApexClipper said:
Is it true that some spiders in the uk are now developing fangs that are capable of delivering their poison to humans?
I have heard this a lot over the past couple of years, and based on the notion that most spiders have enough venom to be harmful to humans.....well, it's a bit
Over the last year or so, I've seen at least three spiders - all miles bigger than I've ever seen in my life before - at least the size of a 50p coin, and this is in the West coast of Scotland!
>> Edited by ApexClipper on Thursday 23 February 11:38
There are plenty of English spiders that can bite humans already as far as I know. I've been bitten by a house spider (see my thread on 'what scares you' - someone on there new the latin name for it), and my boss just told me he's been bitten by a garden spider. Felt like an ant bite really.
I'm not sure about this idea that some English spiders are dangerous to humans but they can't bite us. Is this true or not? The daddylonglegs thing is a myth as far as I know.
RobM77 said:Fair point, but evolution doesn't have a right or wrong answer, whatever works will be favoured so the slightly stronger ones may have had weaker venom and got killed where the little weedy ones prospered.
Maybe it's because they are quite delicate (legs etc) so they need to kill food instantly.
I thought of that, yes - but there are plenty of other small spiders that are equally as delicate that are harmless to humans. Plus, I would have thought that they'd simply evolve to be stronger. Genetic variations in strength must be more common than variations in venom toxicity, so evolution would favour making the spider stronger I would have thought.
[quote=RobM77There are plenty of English spiders that can bite humans already as far as I know.
I'm not sure about this idea that some English spiders are dangerous to humans but they can't bite us. [/quote]
The hobo or brown recluse is resident in the UK and a right nasty little barsteward
www.hobospider.com/stories/hobostory.html
I'm not sure about this idea that some English spiders are dangerous to humans but they can't bite us. [/quote]
The hobo or brown recluse is resident in the UK and a right nasty little barsteward
www.hobospider.com/stories/hobostory.html
One of the most amazing things I've ever witnessed is a British House Spider catching and killing a wasp - without a web 
Incidently the male House Spider dies after mating and is eaten by the female in order to provide neutriants for their offspring
Saw a tarantula in the wild while on holiday in Cuba a couple of weeks ago
Incidently the male House Spider dies after mating and is eaten by the female in order to provide neutriants for their offspring
Saw a tarantula in the wild while on holiday in Cuba a couple of weeks ago
puggit said:
One of the most amazing things I've ever witnessed is a British House Spider catching and killing a wasp - without a web
The British House Spider does not have a web (apart from as a retreat) and generally gets its prey on the move or by dashing out from it's retreat to grab it's prey
Nuclearsquash said:
that whole daddy long legs thing is an urban myth.
www.snopes.com/critters/wild/longlegs.htm
Yep they covered it on mythbusters
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