Look who I found crawling on the parsley.
When I first found them they all looked like the upper 2 caterpillars. I decided to try to identify them to see if they were good caterpillars or bad caterpillars.
My well-used butterfly book that I received in 1972 didn't show any caterpillars resembling mine so I switched to the Internet. All the caterpillars that came up with parsley didn't look anything like it. So, I focused on the white stripe. Everything that came up had stripes going from head to toe, not across.
Next, I tried white band and that did it. The same caterpillar associated with parsley came up. After I clicked into enough sites I discovered that the caterpillar starts out looking one way and then changes. The photo above was taken 24 hours after I first found the caterpillars and you an see that the lower one has changed but the remnants of the stripe is still visible.
The caterpillars will become black swallowtails.
I went back to my old book and read the entry for black swallowtails.
I guess if I would have read instead of looking at the pictures I could have figured it out the old-fashioned way. The swallowtail is the first butterfly in the book.
The oldest caterpillar is turning more yellowish. But, it's still not green.