Pipevine Swallowtails in the Garden

by Maureen Groper

When I moved to San Anselmo in 1985, the large shady swale that ran through the middle of my property was covered with ivy. It harbored rats and was often a haven for yellow-jacket nests. After several years I succeeded in clearing the

swale of this invasive plant. On the advice of Friends of Corte Madera Creek, I replanted only with natives. Those included western sword fern, white-root sedge, salmonberry, and even a pipevine, recommended to me by naturalist Charles Kennard. He believed I would appreciate the latter’s interesting flower.

Fortunately, most of the plants have flourished. The pipevine is growing vigorously—not unlike the dreaded ivy, covering the ground and climbing up anything in its path. I have never seen the flower, but I was treated to a much more exciting development.

One June, I found a most unique caterpillar walking across a path in my garden. I consulted my copy of Common Butterflies of California by the legendary Bob Stewart. Not only did I find a picture of the caterpillar but a photograph of the pipevine swallowtail butterfly into which it would develop. The butterfly is black with a bluish-green metallic color on the hind wings. The female has a row of yellowish-white dots; the male does not. When a pipevine swallowtail is at rest, it folds its wings and you can see a curved row of bright orange dots on the underside. Its body is dark with white spots. It is quite spectacular. I have been fortunate to see them occasionally in my garden.

Then, in March 2014, I was truly rewarded for planting the pipevine. I saw a swallowtail butterfly fluttering around one of the vines. It hovered and hovered for 15–20 minutes. I couldn’t believe the stamina of this fragile creature. Finally, it alighted on a stem. I was able to go right up to it within inches to take pictures. At last, I realized it was laying eggs. Like many butterflies, pipevines only lay their eggs on the host plants that will nourish their larvae when they hatch; this vine is their only host plant.

When it eventually finished and fluttered off, there was a row of little round brownish eggs about the size of a mustard seed. Over the next week or so I kept an eye on the eggs as the leading shoot of the vine inched its way up the tree. When they hatched, I could see 10–12 tiny caterpillars with all their markings munching away. Unfortunately, at this point I went away for a week.

Upon my return there were just four left. For some unknown reason these four never moved on and slowly died. I am hoping the others traveled to another area to continue their munching, then each would form a chrysalis and finally emerge as a lovely pipevine swallowtail. It was disappointing not to see the full cycle during that year, but the pipevine is still in the yard. I hope I will be in the right place at the right time to witness this amazing process again