There are three species of Oeneis (eh-NEE-iss) in Washington: Great Arctic (O. nevadensis), Chryxus Arctic (O. chryxus) and Melissa Arctic (O. melissa). The Great Arctic is found throughout the Cascade Mountain Range from Canada into northern California. Chryxus Arctics are found throughout most of Idaho, Wyoming and Utah, parts of western Montana, Colorado, northern New Mexico, eastern Nevada, and the Sierra Nevada mountains of California, as well as the northern counties of Washington up into Canada, with disjunct populations in the Olympics (Clallam County) and central Cascades (along the Yakima/Pierce county line). Melissa Arctics are found throughout Canada and Alaska, but dip into the north Cascades in Washington, parts of the Rockies from Montana to northern New Mexico, and the White Mountains of New Hampshire.
All three of these species have two-year life cycles, and at least in the Northwest, mostly fly in even-numbered years, so keep an eye out for these cryptic brown beauties this coming summer!
Great Arctic (Oeneis nevadensis)
This species almost exclusively flies in even-numbered years, with scattered records in odd-numbered years, and a few local populations that only fly in odd-numbered years.
Description
Wingspan: 50 to 67 mm
Male: dorsal is golden orange with large dark brown discal cell and stigma. Dark wing margins are flecked with white, creating a scalloped appearance. One to three eyespots on FW and one on HW, on both dorsal and ventral sides. VHW heavily mottled dark brown, gray and white. VFW is similar to but lighter than DFW, with gray and white mottling near the apex.
Female: DFW cell lacks stigma and is not as heavily marked with brown; eyespots are usually larger with distinct white pupils.
Egg: white.
Larva: first instar is pink, later instars are mostly tan with dorsal and lateral stripes in varying shades of brown and white, final instar is usually paler.
Pupa: brown with dark, almost black head and wing casing.
Similar Species
Chryxus Arctic is generally smaller and the eyespots are usually smaller and more numerous.
Habitat & Biology
Habitat: clearings and grasslands in forested areas, often found on and along forest roads.
Overwintering stage: first winter as second or third instar larva, second winter as fifth instar larva.
Larval host: natural hosts are unknown. Larvae reared from eggs in captivity feed on various grasses and sedges.
Adult food source: various flowers including yarrow, mallow ninebark and composites.
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| Male Great Arctics (Oeneis nevadensis), both collected by me on July 11, 2008 at Red Top Mountain in Kittitas County, WA. |
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| Female Great Arctics (Oeneis nevadensis), top was collected by me on July 11, 2008 at Red Top Mountain, bottom was collected by Robert Michael Pyle on July 7, 2010 off Hwy 97 near the Kittitas and Chelan county line. |
Chryxus Arctic (Oeneis chryxus)
This species primarily flies in even-numbered years, but is found in odd-numbered years more frequently than the Great Arctic.
Description
Wingspan: 44 to 57 mm
Male: dorsal is light gold-brown to deep orange-brown with large dark brown discal cell and stigma. Dark wing margins are flecked with white, creating a scalloped appearance, but not as striking as the Great Arctic. One to four eyespots on FW and one on HW, on both dorsal and ventral sides. VHW heavily mottled dark brown, gray and white. VFW is similar to but lighter than DFW, with some gray and white mottling.
Female: DFW cell lacks stigma and is not as heavily marked with brown.
Egg: white.
Larva: first instar is pink, later instars are mostly tan with dorsal and lateral stripes in varying shades of brown and white.
Pupa: brown with dark, almost black head and wing casing.
Similar Species
Great Arctic is generally larger and eyespots are usually larger and less numerous than Chryxus Arctic.
Habitat & Biology
Habitat: dry grasslands, pine forest clearings, often found along forest roads.
Overwintering stage: first winter as first instar larva, second winter as late (4-5) instar larva.
Larval host: Uses a wide variety of grasses (primarily
Fescue and
Poa species) and some sedges (
Carex species).
Adult food source: various flowers, including showy phlox, puccoon, pearly everlasting, daisies and other composites.
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| Male Chryxus Arctics (Oeneis chryxus), both collected by me on June 28 (top) and June 29 (bottom), 2012 at the Sinlahekin Wildlife Area in Okanogan County, WA. |
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| Female Chryxus Arctics (Oeneis chryxus), both collected by me, the top on July 18, 2004 at the Sinlahekin Wildlife Area and the bottom on July 3, 2014 at Long Swamp meadow, both in Okanogan County, WA. |
Melissa Arctic (Oeneis melissa)
Like the previous species, Melissa has a two-year life cycle, but unlike the others it regularly flies in both even- and odd-numbered years.
Description
Wingspan: 42 to 51 mm
Male: partially transparent, charcoal to brown-gray above and below, with dark gray and white mottling on VHW and apex of VFW.
Female: wings more rounded, less elongated.
Egg: white.
Larva: mostly buff with horizontal stripes in varying shades of pale green, white, gray and black.
Pupa: brown with yellowish and gray bands.
Similar Species
None. The VHW is a cryptic mottled gray and brown like the other two arctics, but this species lacks all orange coloration and eyespots.
Habitat & Biology
Habitat: alpine meadows, ridges and scree, usually above timberline (7,000+ feet elevation in Washington).
Overwintering stage: first winter as early or mid-instar larva, second winter as late instar larva.
Larval host: no Washington records. Uses various grasses and sedges in other parts of its range.
Adult food source: alpine flowers.
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| Male Melissa Arctics (Oeneis melissa), both collected by Don Rolfs on July 24, 1995 at 7,000 feet elevation on Slate Peak in Okanogan County, WA. |
