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Caterpillars-venomous or poisonous?

Hello, I've read a lot in books and on the web about poison vs. venom and the distinction between the two but can't clarify whether it is correct to say that a caterpillar with hairs or spines attached to toxin-containing glands is venomous--because it is injecting the toxin via a sort of stinger--or if it is poisonous, since the victim who encounters it has gone and touched the caterpillar and so it is delivered fairly passively on the part of the caterpillar. I realize that if you're the victim you're not going to be debating the word choice, but I'm doing a presentation for some girl scouts and hate to perpetuate an incorrect word choice (some books for kids make no distinctions and talk about poisonous snakes and the like). Thanks for any insight anyone can offer.

Wrong forum, but....
This question should have gone to the "general" forum, which is why it may not have gotten responses before now....

The way 'I' understand it (and I welcome correction if I am wrong), is that "poisonous" means a creature is toxic if you EAT it. "Venomous" means that the creature can deliver toxins without ingestion by the victim. So, the caterpillars you speak of are all venomous. A monarch caterpillar is decidedly poisonous because its body contains the cardiac glycocides it has sequestered from its milkweed foodplant.

Generally speaking, insects with bright, bold colors, are something to steer clear of, even though many harmless insects mimic the colors, patterns, and behaviors of truly venomous or poisonous insects.

Also note that many hairy caterpillars have "urticating" hairs that can cause skin irritation, or allergic reactions, in people that contact them. The caterpillars of the brown-tailed moth are so bad, in fact, that at least two research entomologists died while working on them long-term.

So, good to caution the girls to avoid touching caterpillars no matter how "cute" and fuzzy they might appear.

Eric Eaton
author, "Kaufman Field Guide to Insects of North America"

poisonous vs venomous
Thanks so much for your insight. It really helps. Makes sense too as I guess the caterpillars that ooze secretions that taste/smell bad/are irritating are warning of their poisonous nature/bad taste, as opposed to those with the irritating bristles that "sting". Sorry for posting in the wrong place--it was my first post here, and I thought I was in the general section!

Moving it?
I think that it is easy to fix. Edit your post and you will see, at the top, a number of options. Pick "General" and you are done.

Probably should not have moved....
In this case, probably should not have moved it. I saw the question in the "general" forum, knowing that I had answered it already, and wondering what the heck happened to my response!

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