A little over two weeks ago, I paid my weekly Saturday visit to our local farm market. One of the vendors had potted herbs for sale. I wanted dill, but first picked up fennel. Realizing my mistake, I started to put it back, but then I saw that the fennel had a companion: I recognized this as a Swallowtail caterpillar and made the snap decision to buy the fennel plant, just for the caterpillar! After all, it cost only a dollar.
Some Google research told me this was an Eastern Black Swallowtail caterpillar in its fifth and final instar, which meant it should be ready to pupate soon. For two days, it stayed on that fennel plant, eating about half of it. It had an enormous appetite!
On Monday afternoon, our caterpillar friend did two things. First, it completed evacuated its bowels, leaving a runny brown mess on the side of the fennel pot. (Its earlier frass consisted of tiny black pellets.) Second, it wandered away from the plant. We had a few moments of concern until my eagle-eyed daughter spotted it, up high, crawling along the supports for a shelf near the ceiling of the family room. I stood on a chair and held a stick in front of the caterpillar, who obligingly wriggled onto it. I then placed the caterpillar and the stick in a small aquarium in which I had constructed a jungle gym of sticks and bark. In order to keep the peripatetic creature inside, I taped on a waxed paper lid with small holes poked in it.
Caterpillar wandered back and forth across this small enclosure (about 12″x 6″x 8″) for several hours. Finally, just at our bedtime, it seemed to settle on a branch:By the next morning, the caterpillar had spun some silk to make a sling and suspended itself from the branch like an apostrophe. My research told me that it had exuded some sort of gluey button at its tail to keep it securely attached at that end. Again, it stayed this way for hours. Finally, on Tuesday night, about 24 hours after it first settled on that branch, its skin split, and the chrysalis appeared:By Wednesday morning, the chrysalis had turned brown:I set the aquarium near a north window where it would receive plenty of light, but no direct, hot sunlight. I additionally lifted a corner of the waxed paper and sprinkled some droplets of water in, to keep it from drying out in the air-conditioned environment.
A week later I was excited when I saw the whole chrysalis wiggle several times in a wave-like motion, from head to tail. I was certain that there would be a butterfly by the end of that night. I was wrong. The chrysalis seemed to have undergone some subtle changes, but hatching a butterfly was not one of them:Finally, 12 days after it formed, my daughter and I arrived home from a morning of shopping to find the empty shell of the chrysalis hanging from its branch. . .. . . and a gorgeous butterfly trying to climb up the side of the aquarium:We know this is a female butterfly because she has just one distinct row of yellowish-white dots along the edges of her wings, as well a wide blue band. The orange dots with black spots in the middle are identifiers for Eastern Black Swallowtails.
My husband queued up Elton John on the stereo system, and we took our new butterfly friend to the front porch to set her free. She flew slowly at first, but very soon picked up speed and headed away down the hill. Every time I see a Black Swallowtail this summer, I’ll wonder whether it is “our” Black Swallowtail! “And butterflies are free to fly. Fly away, high away, bye bye!” (Elton John and Bernie Taupin. “Someone Saved My Life Tonight”)