Black swallowtail caterpillar

The black swallowtail butterfly caterpillar has emerged!

When I checked the egg last Tuesday at noon, I discovered it had turned dark.  I looked again at 4:30 and saw a small black dot.  Using a hand lens (a strong magnifying glass), I discovered the caterpillar was out and eating its egg shell.  By 6:30 the egg shell was gone.

Black swallowtail caterpillar on dill plant - day six

Since then the caterpillar has been eating dill and growing.  As of  day six, it is about a quarter of an inch long.  It’s black with a small white patch in the middle and spines along its back.

Black swallowtail caterpillar in cage

I created a cage using a plastic shoe box (8 x 13 inches), nylon tulle from a fabric store, and elastic ribbon.  The dill is in a florist tube filled with water.  I’ll keep the cage indoors where there is plenty of light but no direct sun, and where I can watch it.

The caterpillar is the small black spot on the dill in the image above.  I look forward to watching it grow and change.

5 thoughts on “Black swallowtail caterpillar”

  1. The almost minute-by-minute 🙂 changes are fascinating. Thanks for the “window” into the
    tiny world of butterfly gestation.

  2. I’ve quickly planted my parsley and a fennel plant. I want another black swallowtail. My Milkweed is about 2″ tall; I’m checking it daily.

  3. I was surprised to find 5 of these small caterpillars this morning on the parsley plant I planted in my herb garden window box. I have learned that they will become black swallow butterflies. I most definitely want to keep them going. What else will they eat? I have learned they will quickly consume my parsley plant and I don’t have any Queen Anne’s Lace, what else would suit them? Do they also like milk weed? I have a few milkweed. I live in Ottawa, Ontario

    1. Wendy, you are doing better than I am. I have a lot of parsley but no caterpillars. Congrats for finding, identifying, and wanting to keep them. They also eat fennel. A worst case scenario is to buy some parsley from the grocery store. Better yet would be to find someone else who is growing it and can share. Sometimes they will eat carrot tops. Golden Alexander is another KY wildflower they will eat. Wish I could share mine! Sorry to say they won’t eat milkweed. (Hope the monarchs will find your milkweed). If you weren’t so far away I’d trade parsley for a caterpillar. ☺ Thanks for being in contact and good luck.

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