Etymology

According to one website the generic epithet Gynaephora means 'women-seeker', which refers to the behaviour of the males.^[16] However, the word gynaephora in fact means 'women-bringer' or 'bringer-of-woman'; it is compounded from the Greek γυνή (guní), meaning "woman",^[17] and φορά (phorá), usually meaning "bringer" (along with some other related meanings).^[18] The specific epithet commemorates John Ross who lead the Arctic expedition for which John Curtis served as an entomologist.^[5][11]

Subspecies

There are two subspecies recorded as accepted in The Global Lepidoptera Names Index (LepIndex) belonging to the species Gynaephora rossii as of 2011:^[6][7][19]

• Gynaephora rossii rossii: From North America.^[1][8]
• Gynaephora rossii relictus (O.Bang-Haas, 1927): From Asia.^[1][10] It is sometimes recognised as an independent species.^[1]

These subspecies are not necessarily recognised:

• Gynaephora rossii daisetsuzana (Matsumura, 1928): A subjective subspecies according to the LepIndex.^[19] Native to Hokkaido.^[2]
• Gynaephora rossii lugens (Kozhanchikov, 1948) Lukhtanov & Khruleva, 2015:^[4] As of 2019, this subspecies is too new to have been added to the LepIndex database.^[19] From throughout northern Russia east of the Urals to the Bering Sea.^[4]

Similar species

It is most likely to be confused in British Columbia with Polia richardsoni, which has wings of a similar colour and is in flight at the same month as this moth. That species has a different wing pattern, hair on its eyes and a much thinner antenna.^[16] They can be distinguished from their congener Gynaephora groenlandica in the larvae by the form of their hairs, which are finer and feather-like (plumose) in contrast to stiffer and un-branched (spinulose) hairs.^[21][22] G. rossii imagos (adults) have more patterned wings than G. groenlandica and G. groenlandica lack the broad, dark band along the edge of their hind wings characteristic of G. rossii.^[22] The two species are sympatric in Arctic areas in northern Canada^[6][21][22] and the Canadian archipelago,^[11][22][23] and on Wrangel Island in Russia.^[4] The eggs are somewhat smaller and the cocoons of this species are single-layered, as opposed to the double-layered cocoons of G. groenlandica.^[20]

Gynaephora rossii rossii

The nominate subspecies occurs in the United States and Canada,^[8] In the United States it occurs in Alaska, and isolated populations occur on mountaintops in the Rocky Mountains and the Appalachians. Alpine populations occur in Maine (at the top of Mount Katahdin),^[1][6] in the White Mountains of New Hampshire,^[1][6][16] Wyoming and Colorado.^[16] There is also a specimen from Michigan.^[6]

In Canada it is known from Labrador,^[1][6][16] Yukon (far northern coast and the Richardson Mountains), Northwest Territories (North Slave Region, Fort Smith, Ulukhaktok), Mackenzie County in far northern Alberta, northern Manitoba (outside the town of Churchill), British Columbia (Pink Mountain^[6] and the north)^[16] and Nunavut (Somerset Island,^[11] Bylot Island, north to coasts on central Ellesmere Island).^[6]

It has been recorded from northernmost Alaska in Point Barrow, along the Meade River and elsewhere in Alaska North Slope, and southwards in Lake and Peninsula, the Darby Mountains, the city of Fairbanks, and alpine areas in Kenai National Wildlife Refuge. In Colorado it has been recorded in Clear Creek County, Teller County (Florissant) and Rocky Mountain National Park. In New Hampshire it has been found in Coös County in the village of Jefferson and on Mount Washington.^[6]

Gynaephora rossii relictus

This taxon was originally described from the eastern Sayan Mountains, while the taxon daisetsuzana, now considered a synonym, was only known from the mountains of Hokkaido in Japan.^[1][2][15] It has also been recorded from the mountains of Buryatia and at low elevations in Chukotka Autonomous Okrug.^[6] G. rossii lugens, sometimes considered a synonym of the previous subspecies, occurs in Russia from the Siberian Arctic from the northern Urals and the Yamal Peninsula eastwards to the Chukchi Peninsula, north to the Arctic Ocean^[1][15] and on Wrangel Island.^[4] Southwards it is only found in mountainous areas such as in the Suntar-Khayata Range (eastern Yakutia),^[10][15] the mountains of southern Yakutia^[15] and southwest Irkutsk Oblast, the Yablonoi Mountains of Chita Oblast,^[1] and mountains in the northern regions of Amur Oblast, in Kamchatka and in northern Magadan Oblast along the upper reaches of the Kolyma River.^[15]

Habitat

This day-flying moth is found in tundras in Arctic and Subarctic areas. It also occurs in rocky alpine tundra habitats on top of high mountains,^[16] and has been caught flying in muskeg habitat with trees growing in it in Canada.^[6] It is able to survive in extreme environments such as at 2,200 m above sea level in the Suntar-Khayata Range^[10] or at 2,400 m in Buryatia. It has been recorded at altitudes of 1,561 m in Coös County, New Hampshire, at 800 m in the Richardson Mountains, Yukon, Canada, and at 300 m in Chukotka Autonomous Okrug, Russia.^[6]

Behaviour

Saxifraga oppositifolia is a primary host plant of the caterpillars in Nunavut.

The females have fully developed wings and can fly, although they usually do not,^[10] but are said to "call out" to the males.^[16] This allows the female to save energy.^[10] The males are slightly smaller than the females. Males fly rapidly searching for the females during daylight, and are difficult to catch unless waiting near a "calling" female. They are usually on the wing in July in northern British Columbia, although this can depend on the weather and if the snow has melted.^[16] On Somerset Island in Nunavut the moths and their caterpillars would appear in large numbers for one or two days in June.^[11] In North America as a whole adults have been collected from May to August.^[5] In the mountains of Hokkaido females of this species do fly; in this area they lay eggs on upright, woody plant stems.^[10] On Ellesmere Island the females typically lay their eggs in a mass on or in their cocoon, although they sometimes lay their eggs on the ground or on vegetation around the cocoon.^[20] Females can produce fertile eggs without mating (parthenogenesis).^[5][15] Vladimir Dubatolov was able to rear a female from eastern Yakutia, and subsequently from northwestern Chukotka, without a male present from its emergence from its cocoon, and both times the moths laid eggs which hatched into viable caterpillars. Despite the large distance between these two localities, on Ellesmere Island in Canada Morewood did not observe the same.^[15]

The caterpillars may take many years to metamorphose, seven to eleven years.^[5] In the Suntar-Khayata Range a cocoon was recovered on the end of a branch of a shrub of Pinus pumila. In northwestern Chukotka Autonomous Okrug the caterpillars begin making their cocoons in August.^[15] The caterpillars can be exposed to subzero temperatures, in which they freeze solid, but when brought back indoors, many start moving around again as soon as they thaw. John Ross, when after being trapped in the ice of northern Canada for a number of years during his expedition seeking the Northwest Passage, kept and fed a number in the ship hold. These were repeatedly frozen and thawed through the winter; after four such cycles two survived to pupate, and of those one cocoon was full of flies whilst the other developed into a fully formed adult moth.^[11]

Species interactions

The caterpillars feed on Saxifraga tricuspidata, S. oppositifolia, Salix arctica,^[1] Dryas^[16] and possibly also Potentilla.^[5] It has also been found on Rubus acaulis, and caterpillars have been raised in laboratory settings on raspberry, Rubus idaeus, leaves.^[5] In Russia the caterpillars were successfully raised no a diet of Rosa, Rubus and Taraxacum in the laboratory.^[15] On Somerset Island their main food plants were recorded to be Saxifraga tricuspidata and S. oppositifolia.^[11]

Ross observed many of the caterpillars parasitised by a species of ichneumonid wasp and a type of fly in the Canadian archipelago. Up to six flies can inhabit one caterpillar.^[11] The flies emerge from the cocoons or hibernaculae in the spring.^[11][20] These animals are parasitoids. The flies Ross saw were likely the tachinid fly Chetogena gelida, which appears to be host specific to Gynaephora rossii. On Ellesmere Island, where this moth was found to be sympatric with the closely related G. groenlandica, Chetogena gelida only attacked G. rossii, whereas the new species Exorista thula was only hosted by G. groenlandica.^[20]

Despite living in areas free of bats, they still show avoidance responses to their sounds.^[10] In the High Arctic these moths are preyed upon by birds. The eggs are also eaten by small foraging birds; on Ellesmere Island such birds may tear open the cocoons to feed on the egg mass usually laid inside.^[20]