Argynnis (Speyeria) atlantis brittanae

Argynnis (Speyeria) atlantis brittanae - new subspecies

ZooBank registration: urn:lsid:zoobank.org:act:

Phenotypic description: Males are like nominotypical atlantis ( Fig. 6) but average a scant 1.09 mm larger in forewing length. Measured length of male forewings in the measured series (n=29) is 27-31 mm, averaging 29.92 mm. Color swatches generated using RGB color codes ( Fig. 4) show a slight average difference in the shade of dorsal orange-brown ground color in the study series. West Virginia populations (subspecies brittanae) males tend to have a subtle “warmer” dorsal reddish orange-brown ground color and the dorsal wing margins are less black as in nominotypical atlantis . Nominotypical populations of atlantis have a tanner orange-brown ground color and very dark margins. Variability in any specimen series will show considerable overlap. Large series of both subspecies are necessary for ascertaining an average RGB using a color analysis tool.

Females of the West Virginia populations are of a stronger shade of reddish orange-brown than nominotypical atlantis females ( Fig. 5) which appear to be paler and have a slight yellow component. While males of both atlantis and brittanae have similar, variable dorsal wing pattern, the females differ. Nominotypical atlantis females have a more developed pattern of black markings and darker wing margins, while brittanae females have a tendency for reduced markings and less dark margins by comparison, most noticeably on the hindwings. This gives the females a “brighter” appearance.

The measured females (n=15) average 3.17 mm larger than nominotypical atlantis females in forewing length, ranging from 30-35 mm, averaging 32.42 mm. [Some larger females in West Virginia approach the sympatric A. aphrodite aphrodite phenotype ( Fig. 2), differentiated mainly by more extensive dark wing margins, and the more expansive tan postmedian band on the ventral side of the hindwings, between the outer two rows of silver spots, whereas in aphrodite the inner brown ground color of the ventral side of the hindwings encroaches and partially fills in this tan band.] Interestingly, the series of nominotypical atlantis females and males were of about the same size; the female forewing length averaging only. 42 mm larger than the males. By contrast, subspecies brittanae females were markedly larger than the males, averaging 2.5 mm larger.

Distribution: The range is basically confined to the Canadian Zone of the central Appalachian Mountains (Allegheny Plateau region). Allen (1997) notes that West Virginia populations are disjunct from northern populations. It is primarily an isolate but some contact with ssp. atlantis may occur in southwestern Pennsylvania. County records are as follows: Maryland: Garrett. Virginia: Highland, with an unconfirmed historical sight records in Bath Co. ( Clark & Clark, 1951) and Rappahannock Co. ( Opler, 1995). West Virginia: Barbour*, Grant*, Greenbrier, Hampshire *, Hardy*, Marion*, Mineral*, Monongalia*, Pendleton, Pocahontas, Preston, Randolph, Tucker, Webster. Populations in southwestern Pennsylvania on the Allegheny Plateau require confirmation of assignment to brittanae. The butterfly is best known from Spruce Knob, Canaan Valley and Dolly Sods Wilderness in West Virginia. Counties indicated with (*) indicate historic non-breeding (stray) records ( Allen, 1997; Olcott, pers. comm.). Interestingly, the West Virginia Butterfly Survey (Olcott, pers. comm.) shows the active, current range very restricted, primarily limited to a relatively small area on the Allegheny Plateau. Past records outside the active range indicates historic strays to neighboring counties or perhaps a slightly greater historic range now contracted.

Habitat: Frequently found in high elevation fields, meadows, fens, bogs, pastures and other open areas in association with Canadian Zone and upper Transition Zone forests. They are easily found nectaring on a broad variety of flowers along roadsides in these habitats and through forest.

Hosts: A. atlantis is known to utilize Violets ( Viola sp. ) range wide but the exact species on the

Allegheny Plateau has not been determined.

Flight Period: Single brood. Records span June 8 – October 2, with peak flight in late June and early July. Immature stages of this subspecies have not been studied.

Holotype, allotype, paratypes: Holotype (female) ( Figs. 7 & 9): West Virginia, Randolph County, Spruce Knob Lake , 25 June, 2009. Collected by Harry Pavulaan . Allotype (male) ( Figs. 8 & 10): West Virginia, Randolph County, Spruce Knob Lake , 15 June, 2014. Collected by Harry Pavulaan. Both holotype and allotype to be deposited in the McGuire Center for Lepidoptera and Biodiversity, Gainesville Florida . Paratypes: 28 male and 14 female specimens from Pendleton, Randolph, and Tucker Counties, W. V. retained in the collection of Harry Pavulaan , to be disseminated at a future date . 15 male and 7 female specimens from Pendleton and Tucker Counties, W. V. in the collection of Howard Grisham . 31 male and 11 female specimens from Pendleton and Tucker Counties, W. V., collected by Howard Grisham, John Hyatt and Tom Allen, in the collection of Tom Kral . 14 male and 8 female specimens from Pendleton County, W. V. in the collection of Ricky Patterson .

Etymology: I name this subspecies after my daughter Brittany. The latinized equivalent is

“brittanae”. I propose the common name “Allegheny Fritillary” due to its small range in that region.