The Zerene Fritillary is the most variable of BC fritillary species, and thus the hardest to characterize. Wherever it occurs in BC, it is larger than any of the species still to be discussed. On the ventral hindwing, the basal and median area is a chocolate brown colour that varies in intensity between subspecies. Comparing specimens with the photographs provided is the best way to determine the species.
The mature larva is black. The body is covered with protuberances that bear spines. The bases of the spines are black on the first two rows dorsally and yellow on the third and fourth rows (Hardy 1958a). There are two mid-dorsal narrow yellow stripes. Speyeria zerene and
S. callippe are identical in the larval stages. The egg is 1.0 mm x 0.60 mm and dull cream (Hardy 1958a).
The Vancouver Island and Gulf Islands populations are Bremner's Fritillary, S.z. bremnerii (W.H. Edwards, 1872) (TL: San Juan Is., WA), which occurs south in the Puget Trough and the Willamette Valley to near Corvallis, OR. This is the darkest of the described subspecies. The Alaska panhandle subspecies (a new subspecies) is smaller and somewhat paler; it is expected that S.z. sitka will eventually be found in BC. The Painted Fritillary, S.z. picta (McDunnough, 1924) (TL: Aspen Grove, BC), is restricted to the eastern slope of the Cascades and the southern Cariboo. It is smaller than either bremnerii or garretti. The Washington butterfly atlas (Hinchliff 1996) does not distinguish the Painted Fritillary from the much more widespread Garrett's Fritillary, S.z. garretti (Gunder, 1932) (TL: Cranbrook, BC), which occurs from the Okanagan Valley east to the Rocky Mountain Trench. Garrett's Fritillary occurs south to northeastern Oregon and northwestern Wyoming. It is the largest subspecies and has the lightest ground colour in the basal and median areas of the ventral hindwings. In Washington this species is often confused with the Coronis Fritillary, S. coronis, which has not yet been recorded in BC.
Speyeria zerene sitka P.C. Hammond, J.L. Harry & D.V. McCorkle, new subspecies. Male: Forewing length (n = 9) 23-26 mm (average 25 mm). Dorsal wing surface medium orange to yellow orange with black spots and bars, heavy dark basal suffusion present, and veins of forewing thickly covered with dark scales. Ventral forewing with yellow orange ground colour, brown patches around the silver postmedian spots of the subapical area. Ventral hindwing with a red-brown disc covered with some yellow suffusion, and with a wide yellow submarginal band. Spots brightly silvered and narrowly outlined basally with black scales. Median spots small and round, submarginal spots also small and rounded to flattened. Marginal border red brown like disc. Female: Forewing length (n = 4) 25-28 mm. Similar to the male, but veins of forewing not thickly covered with dark scales. Ventral forewing with red orange ground colour.
Grey and Moeck (1962) associated this disjunct Alaskan subspecies with S.z. hippolyta (W. H. Edwards, 1879) (TL: Oceanside, Tillamock Co., OR) of the OR and WA coast because of the small wing size of the two subspecies. However, S.z. hippolyta usually has a much darker, reddish brown disc and a narrow yellow submarginal band on the ventral hindwing. Between these two subspecies, a third subspecies, S.z. bremnerii, is found from Oregon east of the coast and north to the north end of Vancouver Island. S.z. bremnerii is much larger, with male forewing length 27-33 mm and female forewing length 30-36 mm. A few specimens of S.z. bremnerii from western Washington have the bright red-brown disc and wide yellow submarginal band of S.z. sitka. Thus, it is plausible that S.z. sitka is derived from S.z. bremnerii.
Types. Holotype: male, AK, Haines, 11 August 1949, G.E. Pollard. The holotype is deposited in the California Academy of Sciences, San Francisco, CA, USA. Allotype: female, same data. Paratypes: 1 male and 3 females, same data (CAS); 1 male, AK, Mile 18 Haines Hwy., 7 July 1972, J.L. Harry (JLH); 4 males, AK, Haines, 2.1 miles SW at Mile 26 Haines Hwy., 23 July 1999, J.L. Harry (JLH); 2 males, same locality, 31 July 1999 (JLH).
The genus Speyeria is named for the German lepidopterist Adolph Speyer (1812-92). The name "greater fritillaries" refers to the large size of the species in this genus, in contrast to the lesser fritillaries in the genera Boloria and Clossiana.
At least some populations of all species of Speyeria in BC have individuals with silver spots on the ventral hindwing. By contrast, only one species of Clossiana has these silver spots. The genus is entirely Nearctic, with 14 recognized species, 8 of which are found in BC. Two other species, S. coronis (Behr, 1864) and S. egleis (Behr, 1862) occur immediately south of the BC border in Washington or Montana, and might eventually be recorded in the province. Dos Passos and Grey (1947) produced the definitive treatment of the genus. In this genus, and all genera in the subfamily except Boloria and Clossiana, the aedeagus is open at the proximal end. Dos Passos and Grey (1947) reduced the number of recognized species from more than 100 species to 13 species, and reduced the other species names to either subspecies or synonyms. The dos Passos and Grey paper, Gunder (1929b), Davenport (1941), and Nabokov (1949) set the standard for our modern species concepts for North American butterflies. P.A. Hammond (pers. comm.) has provided the information on the biology and appearance of the larvae.
Southern Interior and Kootenay populations of the Zerene Fritillary have a very protracted flight, from late May to September. This is because the females retreat to high elevations during the dry summer and fly back to the larval foodplant habitat to lay eggs when cooler weather returns in late August or early September. Extant populations of Bremner's Fritillary fly from early July to late August, depending on the elevation of the populations. Mating takes place immediately after adult females emerge from the pupa (JHS). Eggs are laid at the base of the foodplant, Viola sp. (Hardy 1958a). Guppy (1956) observed that eggs kept in captivity did not hatch until the following February. Hardy (1958a) found, however, that the eggs hatched in August and the first instar larvae hibernated until the following spring, when the larvae begin feeding as soon as the foodplant has leafed out. The larvae are very gregarious in the early instars and mostly solitary when mature. Hardy reared them on Viola palustris on Vancouver Island.
The Zerene Fritillary occurs across southern BC. There are, however, only three records from the Lower Mainland, which may represent strays from known Saltspring Island or Orcas Island (Mt. Constitution) populations. On southern Vancouver Island and the Gulf Islands, the Zerene Fritillary is found in mesic meadows and xeric meadows with permanent springs that have not been invaded by Scotch broom. In the Cariboo and the eastern slope of the Cascade Mountains, the Zerene Fritillary is associated with mesic meadows in Douglas-fir habitat. Further east it is found in xeric meadows in sagebrush, ponderosa pine, and dry, low-elevation Douglas-fir habitat.
The Zerene Fritillary is found from the top of the AK panhandle (Haines) and from southern BC east to southwestern SK and south to central CA, NV, UT, and NM.
Recommended citation: Author, Date. Page title. In Klinkenberg, Brian. (Editor) 2021. E-Fauna BC:
Electronic Atlas of the Fauna of British Columbia [efauna.bc.ca]. Lab
for Advanced Spatial Analysis, Department of Geography, University of British
Columbia, Vancouver. [Accessed:
2021-12-04 5:53:02 PM]
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