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Author Topic: Are caterpillars immune to stinging nettle stings?  (Read 10237 times)

Offline chris

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I was asked the other day why a caterpillar can wander, care-free, over a stinging nettle leaf without incurring any painful consequences - i.e. being stung?

Is this just a weight issue - that the caterpillar is too light to impale itself on the nettle leaf spines and hence inject itself with the poison cocktail (histamine and other pro-inflammatory agents) that the spines contain?

Chris



 

paul.fr

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Are caterpillars immune to stinging nettle stings?
« Reply #1 on: 21/05/2007 05:57:15 »
Well, i never really thought about it before! Some birds are immune to the sting of nettles and other stinging plants, so why shouldn't caterpillars.

I know that some types of caterpillars lay their eggs on nettles, so perhaps they are not born immune. but rather, acquire a level of immunity from an early age after being stung in their infancy!

Is that immunity or tolerance?
 

Offline kdlynn

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Are caterpillars immune to stinging nettle stings?
« Reply #2 on: 21/05/2007 06:20:51 »
the eggs are probably laid there so other animals can't eat them. nature is smart!
 

Offline WylieE

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Are caterpillars immune to stinging nettle stings?
« Reply #3 on: 21/05/2007 21:00:47 »
Size does matter!

Would you believe there has actually been a study done on this?

I had to ask for hep on this answer, but a friend who specializes in plant-insect interactions found this paper (Thanks Eric!):

Quote
Responses of Invertebrate Herbivores to Stinging Trichomes of Urtica dioica and Laportea canadensis

We investigated whether stinging trichomes of two plant species, Urtica dioica and Laportea canadensis, are effective defenses against four species of invertebrate herbivores (Vanessa atalanta, Popillia japonica, Chortophaga viridifasciata, and Anguispira alternata). Feeding was compared on leaf pieces of contrasting stinging trichomes density, in petri-dish feeding trials. In addition, a test of snail movement over hairy and shaved L. canadensis stems was carried out. In no case was there significant evidence that stinging trichomes deter or interfere with feeding by these herbivores. Factors of body size and feeding behavior allow them to feed with little interference from nettle stings. Stinging trichomes are known to be effective against mammalian herbivores, and are well-suited to deterrence of large grazers. We therefore hypothesize that stinging has evolved as a defense against mammalian herbivory.


Trichomes are the specialized cells that look like hair on a plant leaf.  They store all types of chemical compounds from the volatiles that make tomatoes smell like tomatoes to the various compounds that make nettles sting.

So these critters can do as well on a normal nettle leaf or one that is shaved- so they must be able to avoid the trichomes pretty well.  It appears that the nettles are just protecting themselves against bigger animals by stinging.

Just makes me wonder- how hard of a job is it to shave nettle leaves- ow!

Colleen
 

Offline chris

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Are caterpillars immune to stinging nettle stings?
« Reply #4 on: 21/05/2007 22:37:54 »
Mmm, great study Colleen, thanks. But it doesn't address the question of why the snails were not stung. I'd have thought that the force of a snail slithering forward would be sufficient to discharge a few trichomes?

Are snails invunerable to nettle poison then?

Chris
 

Offline WylieE

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Are caterpillars immune to stinging nettle stings?
« Reply #5 on: 29/05/2007 07:09:14 »
Having a hard time finding this answer . . but I'll keep looking.
 

another_someone

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Are caterpillars immune to stinging nettle stings?
« Reply #6 on: 29/05/2007 16:06:25 »
Could it be something to do with their slime, either inactivating the trichomes, or providing a barrier?
 

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Are caterpillars immune to stinging nettle stings?
« Reply #6 on: 29/05/2007 16:06:25 »

 

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