Yanking some of the Golden Alexander in my garden (which is technically not invasive, but does spread and needs some aggressive yanking to control it), I happened upon this little critter enjoying one of the leaves. I was happy for the help in keeping the plant under control.
Madeline Bialecki 
Madeline, it looks like a monarch caterpillar! Is it? Are there milk weed near by? Curious, Nona
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I do have milkweeds in the back yard; this creature was out front, but maybe a neighbor also has milkweeds (there is a big push in Michigan to grow milkweed.
Big push here also. I have 2 large areas that I’m cultivating with them:-) 😉!
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What a beautiful caterpillar!
One of my cousins is our resident expert on all things Monarch butterflies, and she confirmed it is a Monarch caterpillar and suggested I put some milkweed nearby, which I have done. The Monarchs are so beautiful–and it turns out so are they in caterpillar stage.
*Assuming* what we call monarchs are just the same as what you have there, that’s no monarch caterpillar. I remembered seeing something similar to yours recently on a blog, and sure enough found this from Massachusetts so perhaps you have a type of swallowtail.. wouldn’t that be grand? Link: https://sggphoto.wordpress.com/2022/09/09/09-09-2022-beauty-on-a-parsley-sprig/
HI Liz, Whatever it is, I put some milkweed next to it to see if it will cacoon, but it may be too late in the year.
Such vivid colors!
Paz
It is so beautiful. It is small but so bright it stood out.