Spicebush Swallowtail caterpillar

Papilio troilus

Spicebush Swallowtail · Staten Island · 5 July 2026

A young Spicebush Swallowtail caterpillar on a sassafras leaf on Staten Island, doing a convincing impression of a bird dropping: glossy dark brown with a white saddle, humped at the shoulders. The camouflage works well enough that something this size is routinely overlooked by the birds that would otherwise eat it. This is a butterfly of the eastern woods, and the caterpillar is only ever found on spicebush and sassafras.

Not the Viceroy it was first written up as. A young Viceroy wears the same bird-dropping colours but is knobbly all over, with a pair of spiky horns behind the head, and this one is smooth. The leaf settles it: the lopsided single lobe is sassafras. A few moults from now it will turn green, fold a leaf around itself with silk, and grow the pair of false eyes that make the later stages look like a small snake.