Apodemia mormo
Mormon Metalmark

Family Description:
Note: Some authors consider this species to be comprised of many subspecies, while other authors treat some of the subspecies as independent species based on the physical appearance of the adults and the timing of their flights.
Caterpillar: The caterpillar is dark purple on top and lighter underneath, with groups of spines that are dark at the base and light at the tips. Its average, full-grown length is approximately inch.
Adult: The butterfly has a wingspan of to 1 inches. The upperside is largely dark brown to black with patches of orange on the forewing and possibly the hindwing. Large white checks are scattered over the entire upper surface. Near the outside edge of both the fore- and hindwing is a row of small white dots. The border has a checkerboard appearance, of brownish black and white. Underneath, the forewing is orangish bordered by grayish brown, and spotted with white. The hindwing is grayish brown and marked with large patches and spots of white.

This species occurs in patches of the Pacific Northwest, Idaho, and Montana, and throughout much of the southwestern U.S.

It largely occurs in dry, open areas, including dunes, chaparral, sagebrush steppe, grasslands, and rocky slopes.


Caterpillar: Caterpillars feed on various species of buckwheat (Eriogonum spp.). Young caterpillars eat the leaves only while older ones eat the stems as well.
Adult: Butterflies obtain nectar from a variety of flowers including buckwheat and rabbit-brush (Chrysothamnus spp.).

Caterpillars construct nests of leaves and silk in which they rest during the day, coming out at night to feed. Each caterpillar undergoes five stages of growth, or instars. In most of its range, there is one generation each year, with the caterpillars overwintering in the physiological state called diapause inside host plant stems or flowers heads. The southern portions of the range may have two generations of caterpillars each summer, in which case only the second generation overwinters. In some locations, eggs have been known to overwinter. Adults generally fly from April through October.

Males perch to wait for receptive females. Females lay pinkish to purple colored eggs in small groups on the lower leaves or singly on other parts of the host plant.

Idaho Status: Unprotected nongame species.
Global Rank:

Varies with subspecies. Subspecies langei of California is ranked as T1, which means it is critically imperiled because of extreme rarity and is imminently vulnerable to extinction. Geographically isolated populations of butterflies such as this subspecies are often genetically isolated, which results in increased sensitivity to habitat loss.

Ballmer, G. R. and G. F. Pratt. 1988. A survey of the last instar larvae of the Lycaenidae of California. Journal of Research on the Lepidoptera 27:1-81.

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.