Spicebush Swallowtail Caterpillar

Genus-Species: Papilio trailus

Description: Young caterpillars resemble bird droppings: chocolate brown with a white saddle mark. Older caterpillars are bright green with 2 large black and yellow eyespots on the thorax behind the true head. Another pair of spots occurs behind these but lacks the “eye.” A double row of small blue circles extends down each side of the back.

Chrysalis: The chrysalis is either mottled brown or green, depending on the time of year and the structure to which it is attached. Brown chrysalides usually occur in the fall and overwinter.

Description: Young caterpillars resemble bird droppings: chocolate brown with a white saddle mark. They also fold the edge of a host plant leaf over to form a flap that provides shelter. Older caterpillars are bright green with two large black and yellow eyespots on the thorax behind the true head. Another pair of spots occurs behind these but lacks the “eye.” A double row of small blue circles extends down each side of the back.

Host Plants: Spicebush (Lindera benzoin), sassafras trees (Sassafras albidum); perhaps prickly ash (Zanthoxylum americanum), tulip tree (Liriodendron tulipifera), sweetbay (Magnolia virginiana), camphor (Cinnamomum camphora), and redbay (Persea borbonia).

Habitat: Woodlands, and open areas near woodlands.

Comments: The Spicebush Swallowtail is an uncommon stray into Wisconsin. The main larval food plants of this species are Sassafras and Spicebush, neither of which is native to Wisconsin.

Adult Butterfly Profile