Description 3 3/8-5 1/2" (86-140 mm). Very
large. Long, dark, spoon-shaped tails have yellow center. Dark
brownish-black above with 2 broad bands of yellow spots converging
at tip of FW. Orange spot at corner of HW flanked by blue spot
above; both recur below, but blue continuing in chevrons across
underwing, which also has orange patch. Otherwise, yellow below
with black veins and borders. Abdomen yellow with broad black
midline tapering at tip; notch on top of abdomen near rear.
Thorax has yellow lengthwise spots or stripes.
Life Cycle Mature caterpillar, 2 1/8-2 3/8" (54-60 mm),
brown or olive, resembling large bird dropping, with dirty
buff patches and saddles and usually red scent horns; feeds
on various citrus trees (Rutaceae), including common prickly-ash
(Zanthoxylum americanum), hoptree (Ptelea trifoliata), and
rue (Ruta graveolens). Chrysalis, to 1 5/8" (41 mm), mottled
gray-brown.
Flight Year-round in South in multiple broods, but scarce
in mid-winter. May-June and August-September broods farther
north produce summer and autumn individuals unpredictably throughout
range.
Habitat Sunny, open areas, forest edges, glades, roads, rivers,
and citrus groves.
Range South Canada south through U.S., east
of Rockies through Mexico, and west along border into Arizona
and California.
More common in South and south-central states than farther
north. Local despite broad tastes.
Discussion Known as the "Orange Dog" by citrus growers,
the Giant Swallowtail is sometimes considered a citrus pest
and is subjected to massive spraying. It is capable of flying
long distances and often strays into northern and midwestern
districts. Adults take nectar from lantana, orange blossoms,
and other flowers. The Giant, the Thoas,and the female Tiger
swallowtails are the largest North American butterflies.
