Endangered Resources Program Species Information
Chryxus Arctic (Oeneis chryxus)

Chryxus Arctic Photo by Kyle Johnson. Check the photos tab for additional photos.
Photo © Kyle Johnson

Overview

Species Overview

There is no overview information available for that species.

Status and NHI Documented Occurrences in Wisconsin

The table below provides information about the protected status (State and Federal Status) and the rank (S and G Ranks) for Chryxus Arctic (Oeneis chryxus). See the Working List Key for more information about the abbreviations used. Counties shaded blue have documented occurrences for this species in the Wisconsin Natural Heritage Inventory database. For invertebrates, dots depict locations from the "Invertebrate Atlas," a database with occurrences of rare and common aquatic and select terrestrial invertebrate species found in Wisconsin and adjacent areas. While the invertebrate atlas is a quality assured database, not all records have been verified. The map is provided as a general reference of where this species has been found to date and is not meant as a range map.

Summary Information
State Status:	SC/N
Federal Status in Wisconsin:	none
State Rank:	S2?
Global Rank:	G5
Tracked by NHI:	Y
Species of Greatest Conservation Need:	Y

Documented locations of Oeneis chryxus in the Natural Heritage Inventory Database as of April 2009.

Detailed Information

Identification: Cream to orange-brown on the upperside with up to four black eye-spots on the forewing and two or fewer on the hindwing. The male is marked with grey-brown in the basal area of the forewing. Hindwing below has only 1 black spot near the lower inner wing margin and is covered with dark brown and grey striations overlain with pale grey veins. Male forewing has a dark patch of sex scales. The underside hindwing is distinctive. Wingspan: 39-50mm. Length of forewing: 22-27 mm. Larvae have red-hairy, cylindrical tan bodies tapered toward the rear with two very short tails. They have a dark tan dorsal stripe and alternating brown, tan and white lateral stripes. The head is yellow brown with six brown stripes (Layberry et al. 1998).

Similar Species: Superficially similar in flight to the meadow fritillary (Boloria bellona) which is usually present with it.

Habitat: Dry grass habitats, cutovers, jack pine barrens, rocky and grassy openings in forest especially along ridges.

Nectar Source: Observed nectaring on cherry and wild strawberry in Michigan (Nielsen 1999).

Host Plant: Grasses (Poacea) and perhaps sedges. Reared on poverty grass (Danthonia spicata) in Ontario (Layberry 1998). Observed ovipositing on rice grass (Oryzopsis pungens) and reed canary grass (Phalaris arundinacea) in Ontario (Scott 1986).

Associated Species: Tawny crescent (Phyciodes batesii), Hobomok skipper (Poanes hobomok), hoary elfin (Incisalia polia), meadow fritillary (Boloria bellona), common ringlet (Coenonympha inornata). Flying with red-disked alpine (Erebia discoidalis) in a jack pine cutover in UP Michigan.

State Distribution: Populations are localized in northern Wisconsin. Bayfield, Burnett, Douglas, Florence, Langlade, Marinette Oneida and Vilas counties.

Global Distribution: Quebec to the Northwest Territories and the Yukon, south into the mountains of California and New Mexico. It occurs in northern Michigan, Wisconsin and west to the Rockies.

Threats: Habitat loss due to woody species and forest encroachment. Since it is unknown where the larvae spend the winter or what the measured effects of fire are, overwintering immatures are assumed to be exposed and vulnerable to being killed by fire.

Phenology: Adults fly mid May to the first week in June, with peak flight usually occurring in late May, perhaps more abundantly in even-numbered years.

Life History: Oeneis butterflies take two years to mature. The first winter is spent as a first or second stage larva and the second winter in the fourth or fifth stage.

Survey Guidance: A strong flier and difficult to approach. Also blends well into the background of lichen-covered rocks. Found sunning on rocks and bare ground in the habitat. Not often found on flowers in Wisconsin, but often rests in patches of shorter grasses or the hostplant. Usually needs to be pursued and netted. New county records should be documented with voucher specimens.

Inventory, Monitoring and Research Needs: Locate additional populations, particularly in sites managed with fire.

Additional Information: The Oeneis chryxus in the Midwest is subspecies strigulosa.

Management Guidance: Sites managed with fire should be divided into several burn units leaving refugia. Special care must be taken not to burn entire stands of the hostplant. Small sites should be enlarged, taking care to protect the open breeding habitat.

Information originally presented as part of the Online Field Guide to Rare Lepidoptera: Bogs and Barrens.

Photos

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