Synonyms and other taxonomic changes
Heraclides pallas (Gray, [1853])
Papilio pallas Gray, [1853]
Papilio astyalus of authors not Godart, 1819
Papilio hozaus Ehrmann, 1921
Papilio bajaensis Brown & Faulkner, 1992 [replacement name for Papilio blumei occidentalis Martin]
Papilio occidentalis Brown & Faulkner, 1984
subspecies pallus
Heraclides pallas pallus (Gray, [1853])
Papilio hozaus Ehrmann, 1921
subspecies bajaensis
Heraclides pallus bajaensis (Brown & Faulkner, 1992)
Papilio occidentalis Brown & Faulkner, 1984
Belongs to subgenus / split genus Heraclides
Identification
Strongly sexually dimorphic.
On the upper side the male has a very broad yellow median band, wider than any other species in its range, and long all-black tails. Females are dark brown with short, stubby tails. Both sexes have a row of yellow crescent-shaped spots along the hindwing margin. Females hind wings may have a metallic bluish sheen above, and typically have two additional concentric rows of crescents, one bluish, and a reddish row inside that (on upper side, inner rows may be faint or absent, and nearly all crescents may vary to yellowish, greenish or bluish). Female forewing is paler apically than toward the base, divided by a stripe of yellowish curving through middle and along leading edge (stronger on under side than upper side).
In south Texas, subspecies pallas can be confused with P. ornythion, but male P. astyalus pallas have a broader yellow median band above, with eighth spot up from the bottom in that band long and undivided. Hind wing tails average shorter and tend to be bent outward at the base. There is usually a prominent (often divided) yellow spot in the upper forwing discal cell that is usually lacking in P. ornythion.
Female P. astyalus pallas have hind wings with a short narrow tail and often additional tail-like projections at ends of other veins, and they have a different spot pattern (see above).
Specimens of P. astyalus bajaensis (western Mexico, sneaking into se. Arizona) have been confused with P. ornythion (to which they are very similar), but P. ornythion does not occur in that region. In males, this subspecies has a narrower upper forwing postmedian band and commonly lacks the pale spot in the discal cell, but is otherwise like subspecies pallas. Females usually have wings shaped like males, but the color pattern is like that of other P. astyalus.
Range
s. TX & se AZ (as strays) to mid-Amazon -
Map (MPG, BOA)
TX subspecies:
pallas (considered to be a full sp. by Shiraiwa et al. 2014
(1), but not by Pelham
(2))
AZ subspecies: bajaensis
Type locality (pallas): Oaxaca, Mexico
Type locality (hozaus): Costa Rica
Type locality(bajaensis): San Antonio microwave tower, Baja California Sur, Mexico
Habitat
Subtropical; females favor more wooded habitats, with males favoring more open areas nearby.
Food
Caterpillars eat foliage of plants in the Citrus Family (Citrus, Ruta, Zanthoxylum, Rutaceae). Adults feed on flower nectar.
Remarks
Note on MPG site that's not adopted by BOA:
Papilio pallas Gray, [1853], formerly a subspecies of 4173
Papilio astyalus Godart, 1819 (extralimital to North America north of Mexico), is elevated back to full species status, ZooKeys, 468: 121.
(1) Print References
Shiraiwa, K., Q. Cong & N.V. Grishin, 2014. A new
Heraclides swallowtail (Lepidoptera, Papilionidae) from North America is recognized by the pattern on its neck. ZooKeys, 468: 85-135.
(1)
