Clodius Parnassian (Parnassius clodius) (Ménétriés, 1855)
Diagnosis: This is one of the three parnassians restricted to North America. It has a white ground colour and black antennae. Unlike most specimens of Rocky Mountain Parnassian (P. smintheus) and Phoebus Parnassian (P. phoebus), it has no red spots on the forewing upperside and the dark spots near the leading edge of the forewing are only slightly darker than other dark areas of the wing. Wingspan: 46 to 72 mm.
Subspecies: Although many subspecies of this highly variable butterfly have been recorded, only three occur in Canada: subspecies claudianus is found in southwestern mainland British Columbia near the coast and on Vancouver Island, generally below 1200 metres' elevation; subspecies pseudogallatinus occurs in mountainous British Columbia, inland from the Coastal Range at elevations generally over 1200 metres; and subspecies altaurus occurs in southeastern British Columbia and adjacent Alberta at elevations between 1200 and 2000 metres.
Range: This western North American species occurs from British Columbia and Alberta southward in the Sierra Nevada to central California and in the Rocky Mountains to Wyoming and Utah. In Canada, it is found in southern British Columbia and in Waterton Lakes National Park in Alberta. Parnassius clodius tends to be found at lower altitudes than Rocky Mountain Parnassian (P. smintheus) but does occur with it at some locations.
Similar Species: The Rocky Mountain Parnassian and Phoebus Parnassian (P. smintheus and P. phoebus) usually have red spots on the forewings. Eversmann's Parnassian (P. eversmanni) has a yellow to yellowish-white ground colour. [compare images]
Early Stages: Larvae are similar to those of other parnassians, but the higher-altitude forms are pinkish-grey instead of black. They feed at night on Dicentra spp. (Fumariaceae).
Abundance: Parnassius clodius can be locally common, but has disappeared from some of its known localities in the U.S., perhaps because of logging activities.
Flight Season: Adults fly mainly in June, but it can be found as late as early August at higher altitudes.
Habits: This species is found in open mountain woods, in meadows, and around rocky outcrops. It tends to be a slow flier with a peculiar bobbing flight and often visits wildflowers.
© 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.
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