Can you identify this caterpillar
Hello: A few days ago I spotted two of these small caterpillars on my curled parsley bush. At first I thought they were monarchs, but realized they were too small and differently patterned. Monarchs are the only butterflies that I've had in my gardens (althogh not this year) so I don't even know if this will be a butterfly or a moth. Today I went out and found only this one. Should I pick this off the plant and grow this on in a jar? I have never done this, and usually feel that we should let mother nature do her thing, but I fear the other one has been eaten (there are birds, cats, squirells, racoons, skuks, and groundhogs around) and I would really like to see what emerges from this. Please advise.