Gynaephora rossii

(Curtis, 1835)

Ross' tussock moth

Gynaephora rossii is a cold-adapted distributed across the Holarctic tundra and alpine regions. The is notable for its extended larval development period of 7–11 years and its ability to survive freezing temperatures. are active during daylight hours in summer, with males actively searching for females while females are largely sedentary. The feed primarily on Saxifraga species and certain willows.

Gynaephora rossii by (c) Doug Macaulay, some rights reserved (CC BY), uploaded by Doug Macaulay. Used under a CC-BY license.

Pronunciation

How to pronounce Gynaephora rossii: //ˌɡaɪniˈfɔːrə ˈrɒsaɪ//

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Identification

Distinguished from the Gynaephora groenlandica by: more patterned in ; presence of a broad dark along the margin (absent in G. groenlandica); and with finer, feather-like () hairs versus the stiffer, unbranched (spinulose) hairs of G. groenlandica. are single-layered versus double-layered in G. groenlandica. May be confused with Polia richardsoni in British Columbia, which differs in pattern, presence of hair on , and much thinner .

Images

Habitat

and subarctic tundra, rocky alpine tundra on high mountains, and muskeg with scattered trees. Occurs from sea level to at least 2,400 m elevation. Survives extreme environments including temperatures that freeze solid.

Distribution

Holarctic: North America (Alaska, Canada, Rocky Mountains, Appalachians), Russia (Siberian from Urals to Chukchi Peninsula, Buryatia, Kamchatka, Magadan Oblast), and Japan (Hokkaido). Includes isolated alpine in Colorado, Wyoming, New Hampshire, and Maine.

Seasonality

active May to August in North America; primarily July in northern British Columbia. Large occur for one to two days in June on Somerset Island, Nunavut. observed making in August in northwestern Chukotka.

Diet

feed on Saxifraga tricuspidata, S. oppositifolia, Salix arctica, Dryas, and potentially Potentilla. Also recorded on Rubus acaulis. Laboratory rearing successful on Rubus idaeus, Rosa, and Taraxacum. In Northern Yakutia, reported on Salix polaris, S. boganidensis, and S. pulchra.

Host Associations

Saxifraga tricuspidata - primary Main on Somerset Island
Saxifraga oppositifolia - primary Main on Somerset Island
Salix arctica -
Dryas -
Rubus acaulis -
Salix polaris - Northern Yakutia
Salix boganidensis - Northern Yakutia
Salix pulchra - Northern Yakutia
Chetogena gelida - , appears -specific to G. rossii

Life Cycle

Extended development with stage lasting 7–11 years. Caterpillars survive freezing and can resume activity after thawing. occurs in . has been documented in females from eastern Yakutia and northwestern Chukotka, producing viable offspring without mating; however, this was not observed on Ellesmere Island.

Behavior

activity. Females have fully developed but rarely , instead remaining stationary and emitting to attract males. Males fly rapidly during daylight searching for females. and practice behavioral by basking in sunshine to elevate body temperature. Caterpillars show avoidance responses to bat sounds despite absence of bats in their range. On Ellesmere Island, females typically lay in masses on or inside their ; in Hokkaido, females fly and eggs on upright woody stems.

Ecological Role

in tundra . Serves as for including Chetogena gelida. for birds including small foraging birds that tear open to consume masses.

Human Relevance

Named for John Ross, leader of the expedition during which the was discovered. Subject of physiological research on and freezing survival. MONA (Hodges) number 8290.

Similar Taxa

Gynaephora groenlandica in Canada and Wrangel Island; distinguished by less patterned , absence of marginal , spinulose (not ) hairs, and double-layered .
Polia richardsoniSimilar coloration and period in British Columbia; distinguished by different wing pattern, hairy , and much thinner .

More Details

Taxonomic history

Originally described as Laria rossii by John Curtis in 1835. Transferred through Dasychira and Byrdia before placement in Gynaephora. include G. r. rossii (North America) and G. r. relictus (Asia), with G. r. daisetsuzana and G. r. lugens sometimes recognized.

Conservation notes

Recorded as common historically on Somerset Island (1832) but appears rare in Hokkaido (only two specimens collected 1920s–1950s). Present in multiple protected areas including Rocky Mountain National Park, Kenai National Wildlife , and Sirmilik National Park.