Page 61 - The Book of Caterpillars: A Life-Size Guide to Six Hundred Species From Around the World

BUTTERFLY CATERPILLARS

FAMILY Papilionidae
DISTRIBUTION Eastern and central North America, south to Peru
HABITAT Open woods, grassland, and desert
HOST PLANTS Several, including carrot (Daucus spp.), parsley (Petroselinum
spp.), Dill (Anethum graveolens), and Parsnip (Pastinaca sativa);
Turpentine Broom (Thamnosma montana) in Arizona
NOTE Caterpillar with a snake-tongue secret weapon for
repelling predators
CONSERVATION STATUS Not evaluated, but common

ADULT WINGSPAN
3⅛–4¼ in (80–110 mm)
CATERPILLAR LENGTH
2 in (50 mm)
PAPILIO POLYXENES
BLACK SWALLOWTAIL 59

FABRICIUS, 1775

The Black Swallowtail caterpillar, a familiar sight in American
home gardens, is black when young with a cream saddle
resembling a bird dropping. As it grows, the caterpillar develops
an orange Y-shaped osmeterium—a feature of swallowtail
larvae—which pops out behind the head when it is disturbed,
emitting chemicals and a pungent odor that repel predators
such as ants. Its appearance, resembling a snake’s forked

tongue, frightens off birds, which also drop the caterpillars after
sampling their bad-tasting skin.

The pupae hibernate and are green if attached to smooth, leafy
places, or brown if attached to rough twigs or bark. When adult
Black Swallowtails emerge, they prefer to fly to hilltops to mate.

There are several generations a year. In the Sonoran and Mojave
deserts of southwestern North America, males and females are
mostly yellow; elsewhere females usually lose their initial yellow
band and become mimics of the Pipevine Swallowtail (Battus
philenor), which is poisonous to birds as an adult.

The Black Swallowtail caterpillar is pale
to dark green with black transverse bands
enclosing yellow (sometimes orange)
spots—markings that mimic the poisonous
caterpillars of the Monarch (Danaus plexippus) Actual size
and Queen (Danaus gilippus) butter ies.