Synonyms and other taxonomic changes
formerly considered a subspecies of the Eastern Tiger Swallowtail (P. glaucus); given full species status by Hagen et al (1991), and others, based on detailed physiological and genetic characteristics.
Pterourus canadensis--sometimes this and related species are split out from Papilio.
Identification
adult: inner margin of hindwing upperside has wide black stripe (whereas the otherwise similar - though larger - Eastern Tiger Swallowtail has a thin black stripe in that area).
Compare images.
larva: mature larvae are dark green, with two spots that look like eyes on the swollen section of the body behind the head; this creates a snake-like profile. Immature larvae are brown and white, resembling bird droppings (CBIF)
Range
northern US, Alaska, and every province and territory of Canada, north to the tundra
Habitat
mainly open woodlands and adjacent areas in the south but also in urban and suburban yards and gardens
north of the treeline, found in the vicinity of dwarf willow and other shrubs
Season
adults fly from May to July
Food
larvae feed on a wide variety of plants, including ash, cherry, poplar, and willow
See Also
Eastern Tiger Swallowtail:
BugGuide,
CBIF
Western Tiger Swallowtail:
BugGuide,
CBIFInternet References
pinned adult images plus description, distribution, biology, etc. (Canadian Biodiversity Information Facility)
pinned adult images plus US distribution map and other info (Butterflies and Skippers of North America; nearctica.com)
