Two-tailed Swallowtail
Papilio multicaudatus W.F. Kirby, 1884

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Diagnosis: Approaching the Giant Swallowtail in size, this spectacular butterfly has broad, bright yellow wings with narrow black tiger stripes and a broad black wing border. It is best distinguished by the two thin tails on the hindwings that give it its name. One of the tails is twice as long as the other. Wingspan: 68 to 104 mm.

Subspecies: Only the nominate subspecies multicaudatus occurs in Canada.

Range: This butterfly has a large range, from Central America through Mexico and the western U.S. It enters Canada in southern British Columbia and Alberta and southwestern Saskatchewan.

Similar Species: Likely only confused with the smaller, single-tailed Canadian and Western Tiger Swallowtails (P. canadensis and P. rutulus). [compare images]

Early Stages: Apple green in colour, the larva, like those of most of this group of butterflies, has two eyespots near its head. It is surmised that these could frighten possible predators. It feeds on the same genera of trees and shrubs as the Canadian Tiger Swallowtail in Canada.

Abundance: The Two-tailed Swallowtail is very localized and considered uncommon in Canada.

Flight Season: Scott (1986) lists only one brood in British Columbia, in May and June, but PWH observed this butterfly on the wing in September in the southern Okanagan Valley during a heat wave.

Habits: Most often found near streams and in moist valleys in arid areas in foothills and the mountains, this species is a regular mud-puddler in southern British Columbia.

Remarks: In the southwestern U.S. and in Mexico, this butterfly reaches a truly great size and is a spectacular sight as it glides up and down canyons and stream beds.

© 2002. This material is reproduced with permission from The Butterflies of Canada by Ross A. Layberry, Peter W. Hall, and J. Donald Lafontaine. University of Toronto Press; 1998. Specimen photos courtesy of John T. Fowler.

The Toronto Entomologists' Association thanks Agriculture and Agri-Food Canada for providing the content and computer code for this web page.