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Species Gynaephora rossii - Ross' Tussock Moth - Hodges#8290

Caterpillar on tundra, Newfoundland - Gynaephora rossii Caterpillar in Becharof NWR - Gynaephora rossii Caterpillar in Denali - Gynaephora rossii mountain caterpillar - Gynaephora rossii Possible Arctiini caterpillar - Gynaephora rossii Possible Arctiini caterpillar - Gynaephora rossii Possible Arctiini caterpillar - Gynaephora rossii
Show images of: caterpillars · adults · both
Kingdom Animalia (Animals)
Phylum Arthropoda (Arthropods)
Subphylum Hexapoda (Hexapods)
Class Insecta (Insects)
Order Lepidoptera (Butterflies and Moths)
Superfamily Noctuoidea (Owlet Moths and kin)
Family Erebidae
Subfamily Lymantriinae (Tussock Moths)
Tribe Orgyiini
Genus Gynaephora
Species rossii (Ross' Tussock Moth - Hodges#8290)
Hodges Number
Synonyms and other taxonomic changes
Gynaephora rossii (Curtis, 1835)
Laria rossii Curtis, 1835
Explanation of Names
Patronym of Admiral Sir John Ross, leader of the Arctic exploration on which Curtis served as an entomologist.
One of two species of Gynaephora in our area (1) (2) (3).
Forewing length: ♂ 15–16 mm.; ♀ 17 mm (4).
"Forewings grey with few markings, consisting of a darker antemedian and erratic postmedian line, usually poorly marked. The reniform is usually indicated by a dark dot or bar bordered by pale scales. Hindwings pale orange-buff with a wide black border, and with the buff largely suffused with grey in many specimens" (5). See the E.H. Strickland Museum species page for an unusually well-marked specimen.

The larvae are unusual among the Lymantriinae in having seven dorsal yellow hair tufts, instead of the usual five (6).
"This species has a Holarctic distribution, occurring in Japan and Siberia in the Old World. The Nearctic populations are found in arctic, subarctic, and alpine tundra from Alaska to Labrador. Isolated alpine populations are found on mountains as far south as the White Mountains of New Hampshire and in Colorado" (4).
"This is a tundra species that occurs in rocky alpine habitats on top of high mountains" (4). Also reported to occur in open alpine bogs (5).
Adults have been collected from May to August (7).
Reported larval hosts included species of Saxifraga and Salix; possibly also Potentilla (Handfield, 1999). Willow buds are favored at some arctic sites. Reported to have been collected on Rubus acaulis and was reared in the lab on R. idaeus (5). PNW reports Dryas as a larval host as well (4).
Life Cycle
"The larvae may take multiple years to complete development (7-11 years in northern Canada (6)), and females can produce fertile eggs without mating. The larvae are covered in dense soft grey hairs, and the cocoon is a grey oval with the larval hair incorporated into it" (5).
Print References
Curtis, J. 1835. Insects -- in Ross, Narrative of a Second Voyage in Search of a North-west Passage, and of a Residence in the Arctic Regions during the Years 1829, 1830, 1831, 1832, 1833: lxx, pl. A, fig. 10.