Mormon Fritillary (Speyeria mormonia) (Boisduval, 1869)

Diagnosis: One of the easiest of the greater fritillaries to distinguish because of its smaller size (wingspan: 40 to 50 mm). The upperside is pale orange with narrow black markings, and the forewing apex is rounded. The forewing underside is orange at the base with narrow black spots, and the hindwing underside is usually greenish with silver spots (often these are an unsilvered greenish-tan colour).

Subspecies: Four subspecies occur in Canada. Subspecies eurynome is larger and paler than other forms and occurs from Colorado into Manitoba, Saskatchewan, Alberta, and southeastern British Columbia. Subspecies opis, which occurs through most of British Columbia and dry areas of Yukon, is smaller and darker and the spots on the hindwing below are usually silver; subspecies bischoffii is barely distinguishable from subspecies opis except that the spots are usually unsilvered; it occurs in coastal Alaska and into Canada at higher elevations in the St. Elias range of southwestern Yukon; and subspecies erinna, in which the hindwing underside is reddish brown with little green shading, occurs from northern California into southernmost British Columbia on Anarchist Mountain near Osoyoos.

Range: The Mormon Fritillary is found from central Yukon south through British Columbia into the western U.S. It ranges east to Stony Mountain in southern Manitoba.

Specimen collection data

Similar Species: Although a greater fritillary, it could be mistaken for a lesser fritillary because of its relatively small size.

Early Stages: The grey-brown to tan larva has black stripes and dark spines.

Abundance: This butterfly can be common in the mountains, where it occurs in dry grassy meadows at high elevations; it is usually less common in the Prairies, rare and local in Manitoba.

Flight Season: Adults are generally on the wing in July and August.

Habits: The Mormon Fritillary tends to be a weaker flyer than other greater fritillaries and stays close to the ground.

© 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.