Speyeria mormonia

Speyeria mormonia (Boisduval, 1869)

(Figure 5E, 48)

Argynnis Mormonia Boisduval, 1869: 58.

Speyeria mormonia (Boisduval) [dos Passos and Grey 1945a].

Common names. Mormon fritillary, mormonia fritillary, mountain fritillary.

Type deposited. Lectotype (male) designated by dos Passos and Grey (1947) at National Museum of Natural History (Figure 48).

Type locality. Oregon. Defined by dos Passos and Grey (1947) as Salt Lake City, Salt Lake County, Utah. However, Grey (1974, 1989) discussed the possibility that fixation of the type locality as “Salt Lake” was a mistake and speculated the type specimen may have been taken from somewhere in California. However, he felt it would be hard to prove given the subtle nuances in wing pattern and coloration of Speyeria and also felt no present concepts are disturbed if the locality remains as defined. Miller and Brown (1981) later defined the type locality to the vicinity of Pyramid Lake, Nevada. Emmel et al. (1998a) further defined the type locality to Little Valley, W. of Washoe Lake, Washoe County, Nevada.

Type label data. “ Mormonia Bd. Lac Sal; EX MUSAEO Dris. BOISDUVAL; Argynnis Mormonia [male] Bdv. ex typ. sp.; Oberthur Collection; Barnes Collection”.

Identification, taxonomy, and variation. There are approximately 10 described subspecies in the mormonia complex. Speyeria mormonia can be identified by the smaller size (wingspan 38-60 mm) compared to other Speyeria; on average it is the smallest species in the genus. The antennal clubs are relatively expanded compared to other Speyeria species. Penz and Peggie (2003) reported that female S. mormonia had an accessory bursal sac, but this has not been reported previously nor observed in recent dissections I have made. The forewings are short and rounded and there is usually some basal darkening. The dorsal wing surface does not have black scaling on veins but does have a complex pattern of black spots, bars, and chevrons with a black border. The ventral surface of the hindwing disc is pale yellow to pale brown, occasionally greenish in hue (in the Cascades of Washington), but otherwise similar in color to ventral forewing. Black Hills, South Dakota populations have a dark brown disc. The silvering of the ventral hindwing spots is variable within and among populations (spots are partially silvered in the California Sierra Nevada Mountains or primarily yellow in the Great Basin), and spots tend to be smaller than on most Speyeria. Populations occur in northern Nevada and southeastern Oregon where individuals are unsilvered ventrally with a yellow ground color and little pattern. A subspecies isolated in the White Mountains of Arizona, S. mormonia luski (Barnes and McDunnough), is unlike other S. mormonia in appearance and bears white, ‘unsilvered’ hindwing spots rather than the usual ‘unsilvered’ condition of S. mormonia forms that have spots filled with brown. Eggs are small and tan-colored (may be yellowish when oviposited and become purplish-tan later). Larvae are brown to gray, or yellowish to orange with black spots and lines. Spines are short and paler at the base. Larval coloration is likely variable throughout the range of S. mormonia due to local climatic conditions. See Grey (1974) for discussion on S. mormonia subspecies concepts.

Range. Speyeria mormonia occurs along the mountainous regions of western North America, from southcentral Alaska south to central California in the Sierras, east-central Arizona, north-central New Mexico, extending east to southwestern Manitoba and the Dakotas. It occurs at higher elevations and further north than most other Speyeria (Opler and Wright 1999; also see Eriksen 1962, Kozial 1994). It occurs at sea level in Alaska, the sagelands of the Great Basin, and the plains of the Black Hills.

Life history. Known to occur in mostly subalpine habitat, including Canadian to lower Alpine Zone meadows, moist prairie valleys/meadows, and openings in subarctic forests. Speyeria mormonia is the most likely member of Speyeria to occur in high mountain habitats. Males patrol all day just above the ground in open vegetated areas and in meadows at lower elevations (Scott 1975). Females lay eggs singly and haphazardly near host plants. Unfed first instar larvae hibernate. Flight period is mid July through October in the southern part of its range, July through August in the northern part. Adults can fly great distances, especially females, and can stray into foothills or the Colorado plains. Boggs (1986, 1987a,b, 1988, 1997a,b), Boggs and Jackson (1991), and Boggs and Ross (1993) provide numerous studies on the ecology of S. mormonia. Boggs and Murphy (1997) discussed how climate change might affect S. mormonia individuals by reducing available nectar sources, with consequent effects on individual reproduction and survival. Montane species such as S. mormonia may be negatively affected by long-term climate warming trends.

Larval host plants. Viola nuttallii, V. palustris, V. adunca, V. adunca variation bellidifolia, V. sororia (Scott 1986b; Robinson et al. 2002).

Adult food resources. Sagebrush, rabbitbrush, mud (Scott 1986b; Pyle 1995), alpine fleabanes and other composites (T. C. Emmel in litt.).