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Species Aglais milberti - Milbert's Tortoiseshell - Hodges#4433

Mountain butterfly - Aglais milberti Milbert's tortoiseshell - Aglais milberti Aglais milberti Milbert's Tortoiseshell - Aglais milberti Milbert's Tortoiseshell - Aglais milberti Milbert's Tortoiseshell - Aglais milberti Aglais milberti Aglais milberti
Show images of: caterpillars · adults · both
Kingdom Animalia (Animals)
Phylum Arthropoda (Arthropods)
Subphylum Hexapoda (Hexapods)
Class Insecta (Insects)
Order Lepidoptera (Butterflies and Moths)
Superfamily Papilionoidea (Butterflies and Skippers)
Family Nymphalidae (Brush-footed Butterflies)
Subfamily Nymphalinae (Crescents, Checkerspots, Anglewings, etc.)
Tribe Nymphalini
Genus Aglais (Tortoiseshells)
Species milberti (Milbert's Tortoiseshell - Hodges#4433)
Hodges Number
Other Common Names
Fire-rim Tortoiseshell
Synonyms and other taxonomic changes
Vanessa milberti Godart, 1819. Type locality: United States of America [rationalized as probably "neighborhood of Philadelphia, Pa." by dos Passos in 1938]
Aglais milberti (Godart) ??authorship??
Nymphalis milberti (Godart) ??authorship??
Vanessa furcillata Say, 1825. Type locality: “North-West Territory...vicinity of Fort William, an establishment of the Hudson Bay Fur Company” [Ontario]
Vanessa milberti var. subpallida Cockerell, 1889. Type locality: Westcliffe, Custer County, Colorado
Aglais milberti viola dos Passos, 1938. Type locality: Doyles Station, Newfoundland
Nymphalis milberti pullum Austin, 1998. Type locality: Ditch Camp, Apache County, Arizona
fairly common in most of its range
numbers do not fluctuate as greatly from year to year as does the California Tortoiseshell [Butterflies of Canada, CBIF]
the only resident species in this genus in North America; the other species listed at All-Leps was a specimen of the European Aglais urticae collected in Nova Scotia on 7 November 1970 after it flew out of a box that had recently been sent from England (see account of Small Tortoiseshell at CBIF)
wingspan 34-63 mm
Adult: forewing tip squared-off; upperside black with wide orange submarginal band grading to yellow at inner edge of band; two orange patches along costa in dark basal area; narrow black marginal border on both wings; hindwing border may contain some blue spots
underside dark brown in basal area and lighter brown toward the margins

Larva: mature stage black with branching spines on back and sides; middorsal row of spines begins on abdominal segment two; young larvae heavily speckled with small white flecks and orange spots that form broken subdorsal line; broken yellow lateral line along each side
all of Canada and Alaska south of the tundra, all of western United States, plus northeastern US (absent from SC, GA, and the gulf states from Florida to Texas)
wet areas near woodlands, moist pastures, marshes, woodland trails and roads
adults fly from April to October, with two or possibly three overlapping generations
larvae feed on stinging nettles (Urtica spp.)
adults feed mostly on sap, rotting fruit, and animal dung, but are also seen nectaring on flowers
Life Cycle
two or three overlapping generations per year; eggs laid in large batches of up to 900 on underside of foodplant leaves; young larvae live in communal nests on the foodplant; mature larvae live singly in folded leaf-nests; overwinters as an adult, sometimes in small groups
A quick, active species that flits rapidly about its territory, often along a woodland road. It regularly alights on the ground or on a rock or tree with its wings spread flat. Specimens emerging from hibernation in the spring are usually quite pale and worn. [from Butterflies of Canada, CBIF]

Hodges #4433
See Also
Compton Tortoiseshell is superficially similar
in the west, California Tortoiseshell is somewhat similar
Internet References
pinned adult image plus US distribution map, description, biology, flight season, food, and habitat (Butterflies and Skippers of North America,
pinned adult image plus various information (G.G. Anweiler, U. of Alberta)
classification and synonyms plus common name reference [Fire-rim Tortoiseshell], food plant, live adult images, links to several web sites, literature references (Markku Savela, FUNET)
North American Butterfly Association includes early instar larval images larval image