Arctia alpina (Quensel, 1802)
Arctic Tiger Moth
RUSSIA, S Siberia, SW Tuva reg., W Tannu Ola Mt. rng., Sogly v., 9186 ft
June 03, 2003, Collector unknown.
Specimen courtesy of LGCC
Photograph copyright: Merrill A. Peterson
Acerbia alpina is a spectacular, large (FW length 20-23 mm) colorful arctic and subarctic erebid moth that has been found on rocky mountain slopes in southern Yukon Territory not far from British Columbia. The forewing has an abstract pattern of cream spots on a black background with nearly undiscernible typical lines and spots; however, the pattern is probably black on white with fused thick black transverse lines and black veins on a pale background. The hindwing is orange with a hoary dark gray base, black veins, discal spot, and incomplete postmedial line. The head, thorax, and abdomen are nearly black with patches of orange, especially on the legs.
The relatively large size and distinctive colorful pattern identify this species. The only PNW moth with which it could be confused is Arctia yarrowii, another denizen of barren rocky slopes and mountaintops. Arctia alpina has a unique spotted pattern of the dorsal forewing, whereas the similarly colored A. yarrowii has this forewing pattern more clearly oriented in transverse bands.
Arctia alpina is a denizen of rocky slopes and mountaintops.
This species has yet to be documented as occurring in the Pacific Northwest but has been found not far north of the British Columbia-Yukon Territory border. It almost certainly occurs in northern British Columbia.
This is a holarctic moth. The range extends east from Yukon Territory and northern Northwest Territory to northern Scandinavia.
Adults fly during the summer, typically in late June and July. They are diurnal.
Rönkä K, Mappes J, Kalla L, Wahlberg N. 2016. Putting Parasemia in its phylogenetic place: a molecular analysis of the subtribe Arctiina (Lepidoptera). Systematic Entomology 41: 844–853.