Butterfly Gardening

Black Swallowtail caterpillar on dill with dew

Black Swallowtail caterpillar,
Papilio polyxenes

I deftly plucked one from the stem—
a plump striped caterpillar who was making a meal of the feathery fingers of dill at the edge of our vegetable garden. And, pleased with my find, paused just long enough to snap off several stems of Queen Anne’s lace before running inside with my prize.

Setting up a small bud vase in the center of the table, I transferred her gently to Queen Anne and sat down to refresh myself from the heat of the afternoon.
Two summers ago, I had set up a vase in just the same way. Having found a caterpillar that I recognized to be of a Black Swallowtail, I watched her grow as she contentedly grazed for days amid a small bouquet of wildflowers, became a chrysalis and emerged into the freedom of an early August morning--the constant shower of frass, the only downside to hosting this unusual dinner guest.

And so I thought it would be with this one.
Yet, within the first several minutes, she dropped to the table, made a hasty trail to the edge, and tumbled off into my waiting hand below. Replacing her again and again, I watched as she repeatedly dropped and nimbly raced each time to the same edge.

My invitation to stay a while apparently not to her liking, I took her back to the dill in the garden, quite sure that by morning her walkabout would have taken her far away.
Instead, I found her tethered to the spot from which I had first picked.
Now a butterfly grows in my garden.

Tethered to a stem with silken strands

Dill

This year, Black swallowtail caterpillars, whose foodplants are parsley, fennel, carrot and other umbelliferae, have chosen to devour the dill in my garden. Commonly cultivated dill, Anethum graveolens, has bluish-green fern-like leaves and compound umbels of tiny, bright yellow flowers.
In the days between hatching from a single small yellow egg and forming a chrysalis from which will emerge a lovely swallowtail, these eating machines shed their skin several times as they grow through 5 instars (developmental stages between molts). This small and spiny dark caterpillar with the white saddle (photo below) is an early instar and barely resembles the later black and yellow speckled instars.

early instar on dill