A dark butterfly flying around the pipevine outside my study window caught my attention. Ooh, might it be a pipevine swallowtail?
Our pipevine (Aristolochia macrophylla) definitely needs some caterpillars this year.
We didn't have any last year, and it's a strong grower.
Planted specifically as a host plant for pipevine swallowtails, it coexists with Carolina jessamine on this trellis, producing large green heart-shaped leaves and spreading vigorously. Its small greenish purple flowers, shaped like a pipe, appear in mid-spring (late April-early May for us).
The afternoon light was harsh, but I was able to determine that it was a female pipevine swallowtail, depositing eggs on young leaves (which are preferred).