Speyeria mormonia
Mormon Fritillary

Family Description:

Caterpillar: The caterpillar is grayish brown to light brown, striped lengthwise along the back with black, and covered with short, light colored spines.
Adult: The Fritillaries as a group are very similar in appearance, and the differences between individual species are often minor and difficult to see. Positive identification to the species level is difficult and requires detailed examination. This is a medium-sized butterfly, small for a Fritillary, with a wingspan of 1 1/2 to 2 3/8 inches. The tips of the forewings appear rounded. Its appearance varies somewhat between regions. The upperside ranges from golden orange to orangish brown, and is edged with one thick or two thin black lines. The forewing is marked with short, wavy, nearly parallel black lines. There is a vertical, wide, wavy and wandering black line across the wing’s center, followed by a row of black spots, followed by a row of black, inverted "v"-shaped marks, each possibly capping a yellow spot (sometimes absent), along the outside edge. The wing veins are outlined thinly in black, or not at all. The hindwing is similarly marked. Underneath, the forewing is golden yellow, tinged with orange at the base. It is marked as above, and additionally with light yellow, white, or silver spots at the tip and along the upper half of the outer edge. The underside of the hindwing ranges from reddish brown to light brown to greenish brown, and is marked with pale spots, either yellow, white, or silver; the spots on the outer half of the wing are arranged in two curved rows, with a band of yellow in between.

This species ranges from southern Alaska south to California, Utah, most of Idaho, and northern New Mexico, and east to southwestern Manitoba.

It can be found in middle and high elevation meadows, sagebrush steppe, and prairies.


Caterpillar: Caterpillars feed on the leaves of several species of violets (Viola spp.).
Adult: Butterflies drink flower nectar, and obtain additional moisture and salts from mud.

There is one new generation of caterpillars each year. Eggs hatch in the fall; the newly emerged caterpillars, having not yet fed, enter a physiological state called diapause to overwinter. In the spring the young caterpillars feed on the new leaves of host plants. Adults generally fly from the first of June through October. The butterflies are capable of flying significant distances. Fritillaries are long-lived for a butterfly, surviving several weeks to months.

Males actively patrol low to the ground in search of receptive females. pheromones, chemicals used to locate and attract the opposite sex, are produced by both male and female Fritillaries. These chemicals are believed to play an important role in assisting these butterflies to find and recognize other members of their own species. Eggs are laid singly and randomly near host plants. In cases where the violet plant has already withered and blown away, females are still able to lay their eggs near to where the host plant will reappear the next spring. This is possible, it is believed, because females are able to locate violet roots by smell!

Idaho Status: Unprotected nongame species.
Global Rank:

G5; populations are widespread, abundant, and secure.

Ferris, C.D. and F.M. Brown (eds.) 1981. Butterflies of the Rocky Mountain States. Univ. of Oklahoma Press, Norman, Oklahoma, USA, 442 pp.

Opler, P. A., H. Pavulaan, and R. E. Stanford. 1995. Butterflies of North America. Jamestown, North Dakota, USA: Northern Prairie Wildlife Research Center Home Page. http://www.npwrc.usgs.gov/resource/distr/lepid/bflyusa/bflyusa.htm (Version 05Nov98).

Opler, P. A. and A. B.Wright. 1999. A Field Guide to the Western Butterflies.   Second Edition.  Peterson Field Guide Series. Houghton Mifflin Company, New York, New York, USA, 540 pp.

Pyle, R. M. 1981. National Audubon Society Field Guide to North American Butterflies. Alfred A. Knopf, Inc., New York, New York, USA, 924 pp.

Scott, J. A. 1986. The Butterflies of North America. Stanford University Press, Stanford, California, USA, 583 pp.

Stanford, R. E. and P. A. Opler. 1993. Atlas of Western U.S.A. Butterflies (Including Adjacent Parts of Canada and Mexico). Published by authors, Denver, Colorado, USA, 275 pp.