Yesterday afternoon I discovered two large, bright-green-and-black banded caterpillars munching on my fennel. I pulled them off, and they spread a stinky smell that stuck to my fingers. I put them both into an empty watering can, looked them up on the web, and discovered that they were black swallowtail larvae — nearly as striking in their adult butterfly form as they were in the caterpillar stage. Too pretty to kill, but not pretty enough to sacrifice my fennel.
I placed them in the parsley and basil at the other end of the garden. When I checked later, they were in pretty much the same spots I’d left them in, but I started to worry that maybe they weren’t eating, so I put one of the caterpillars back on the fennel and left the other on the Thai basil.
Today the caterpillar on the fennel is doing fine. The one that I left on the basil is nowhere to be seen.