Pipevine Swallowtail, Battus
philenor
Papilionidae or Swllowtail Family
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Large
butterfly with a
wingspan of 3 to 6 inches. Wings are sooty
black on top, with a neat row of white spots and another of white
crescents. The individual at left is a female. The male is
similar,
but the hindwings are iridiscent blue. Underneath, the forewings
repeat the black-with-white-dots-and crescents pattern. The
hindwings
have a blue to black outer portion with a single row of orange spots,
and an outer row of white spots. Each hindwing ends in a short
tail, the "swallowtails" of the common name. Flies in the summer.
Caterpillar is red or black with bright red to orange spots down either
side. It has black tentacles at both ends, the frontmost pair
being about twice as long as the others (the unfortunate individual
below has lost one of its front tentacles). In the picture at
right below there is a forked orange "tongue" on the caterpillar's
head. This is the osmeterium, a defense organ that can be
suddenly everted to startle predators, and which produces a foul
odor. All swallowtail caterpillars have an osmoterium. |
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The adult drinks nectar from a
wide variety of plants, including thistles and ironweed, both common
in the Park. The caterpillar feeds only on plants of the genus Aristolochia
(pipevines), which contain toxic aristolochic acids. The
caterpillar
takes these acids in, making them, and the adults they will become,
toxic, and thus distasteful to predators. In our area, two plants
that
used to be in Aristolochia
and are eaten by pipevine swallowtail cats are Virginia snakeroot and
Dutchman's-pipe; however, neither of these has yet been reported in
Wildwood. It is a a mystery how the photographed caterpillar got
so
fat in the Park. Found from New England to
Florida, and westward in the south to California, anywhere Aristolochia plants are
found. The adults prefer open meadows and grasslands. |
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The caterpillar is distinctive, and easily identified. The adult is a member of the blue and black swallowtail group, all of which mimic each other and are protected by resembling the poisonous members of the group. In the Park, the following members are known. Spicebush Swallowtail has two rows of orange spots underneath. The Eastern Black Swallowtail also has two rows of orange spots beneath, and a blackspot on an orange spot above. The black form of the female Eastern Tiger Swallowtail has a row of small orange spots at the edge of the wing underneath. The Red-Spotted Purple has no tails at the end of the wings, and extra orange spots outside the neat row beneath.