I was out trimming branches from a large cherry tree on my property and while in the tree I felt a burning sensation on my arm. I look to my arm and there is a strangely colored furry caterpillar on my arm chewing on me. It had a red face, patterned green and yellow body, and a bushy yellow tail, about 1 inch in size.

My wife is gravely concerned because she seems to think it is highly venomous, she flicked it off my arm and now I cant find it to take a picture. This occurred about an hour ago and my upper arm is starting to burn. It feels similar to a hornet sting. I am located in western Pennsylvania.

Is this truly something to be concerned about or am I possibly having an allergic reaction? Any idea what kind of caterpillar might have bit me? Are there any highly venomous caterpillars in western PA?

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    random strangers on the internet is not the best source of advice for this, except this: find the number of the poison/venom emergency center next to you, and call them right away.
    – njzk2
    Commented Jun 27, 2021 at 21:16
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    This site has some good caterpillar ID guides with pictures: leafyplace.com/stinging-caterpillar. The good news is that in North America, you're unlikely to encounter a deadly caterpillar. See a doctor if you think you're having an allergic reaction, or if your symptoms are worrying and/or they don't seem to be going away on their own.
    – csk
    Commented Jun 27, 2021 at 21:34
  • I’m surprised that you say it was actually biting/chewing on you. I've never heard of them actually biting people. I’ve personally had an irritating hairy caterpillar land on my neck (dropped from a tree) which I unknowingly smushed, which left a rash for a day or two. However, that’s from the spines/hairs it has, rather than a true bite. Was there a single spot or puncture wound, or more of an area of irritation? Commented Jun 28, 2021 at 11:56
  • @fyrepenguin No definitely biting me! Single little spot where he was chewing, with a rash around where his body was, I am guessing from the spines. I even showed it to my wife because the little guy was going to town on my arm and I thought it was the strangest thing. I am guessing the burning though was from the spines and not the chewing lol. Commented Jun 28, 2021 at 21:06
  • @maple_shaft did the caterpillar look anything like this one? Commented Jun 30, 2021 at 0:24

1 Answer 1


Ok, You aren't going to die, It is called a Northern American Caterpillar, it usually is found on parsely or dill. The burning sensation on your arm is skin irritation and is normal. It is the caterpillars defense system to prevent anything from eating it. I would go to the doctor and see if it is an allergic reaction, but if you aren't allergic, you should be good.

Link to article

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    Can you give any sort of reference, image, or supporting information for your answer? Commented Jun 28, 2021 at 19:14
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    No species that I can see that is called "Northern American" moth or butterfly. Please update your post with supporting information, link, pictures etc for the species you indicate.
    – bob1
    Commented Jun 28, 2021 at 23:39
  • @fyrepenguin Gladly owlcation.com/stem/caterpillar-identification Commented Jun 29, 2021 at 16:33
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    @JosephCasey I don't see anything in the list there called a "Northern American Caterpillar". That's equivalent of identifying a snake as a "Northern American Snake" because your found it in the US instead of specifying the actual species. Without being more specific, this effectively doesn't answer the question Commented Jun 29, 2021 at 18:59

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