Black Swallowtail

This large swallowtail butterfly is a mimic of the unpalatable pipevine swallowtail (Battus philenor). It has a wingspan of 3¼″ to 4¼″.

The upper side of the forewing is black with two rows of yellow spots, one on the submarginal band, one on the median band. Both rows of spots extend to the forward (costal) margin of the wing. There is also a narrow, interrupted, yellow border on the outer margin, and a single yellow spot in the area just below the tip (subapical area). On the male, the medial spots are large and closely spaced. On the female they are narrow and widely spaced.

The caterpillar is variable in color and up to 2″ long. It appears smooth but is actually densely covered with minute hairs. The background color is usually green but may be white, yellow, brown and white, or black (see Comments below). The thorax is swollen and the head is held beneath the thorax. The thorax of the green form caterpillar is green with 2 black stripes in an inverted “V” pattern and 3 black spots. Each abdominal segment is green with a broad, horizontal black band. In each black band there are 6 yellow spots. There is also a narrow black band in the fold between abdominal segments. The legs are greenish-white with 2 black spots.