Plants and Animals

Euchloe ausonides Large marble

Key Characteristics

The upper sides of the wings are white with a black-patterned apex and a black, crescent-shaped mark along the leading edge of the forewing. The underside of the hindwing is marbled with greenish gray scales. Antennae are checked with black. Middle green band has two prongs near leading edge of the forewing. The caterpillar is striped with black, yellow and white.

Status and Rank

US Status: No Status/Not Listed
State Status: SC - Special Concern (rare or uncertain; not legally protected)
Global Rank: G4? - Apparently secure (inexact)
State Rank: SH - Possibly extirpated


CountyNumber of OccurrencesYear Last Observed
Keweenaw 1 1987

Information is summarized from MNFI's database of rare species and community occurrences. Data may not reflect true distribution since much of the state has not been thoroughly surveyed.


Open areas, rock outcroppings and trails, frequently on ridge tops. This species is known only from Isle Royale in Michigan along rocky outcroppings and forest openings. Major food plants are crucifers (e.g., Arabis drummondi), mainly rock cresses (Arabis sp.).

Natural Community Types

For each species, lists of natural communities were derived from review of the nearly 6,500 element occurrences in the MNFI database, in addition to herbarium label data for some taxa. In most cases, at least one specimen record exists for each listed natural community. For certain taxa, especially poorly collected or extirpated species of prairie and savanna habitats, natural community lists were derived from inferences from collection sites and habitat preferences in immediately adjacent states (particularly Indiana and Illinois). Natural communities are not listed for those species documented only from altered or ruderal habitats in Michigan, especially for taxa that occur in a variety of habitats outside of the state.

Natural communities are not listed in order of frequency of occurrence, but are rather derived from the full set of natural communities, organized by Ecological Group. In many cases, the general habitat descriptions should provide greater clarity and direction to the surveyor. In future versions of the Rare Species Explorer, we hope to incorporate natural community fidelity ranks for each taxon.

Management Recommendations

The Large marble is known only from Isle Royale in Michigan and is considered imperiled or critically imperiled in the state. Little is known about the species' status, distribution, life history, ecology and threats in Michigan. Surveys are needed to determine this species' current status, abundance and distribution in the state, especially in the western Upper Peninsula region (e.g., Porcupine Mountains and Keewanaw Peninsula). Research to obtain more information about this species' life history and ecology and efforts to assess threats to this species also are warranted. Adult food sources for this species in Michigan need to be identified. The sites at which this species has been documented should be protected and maintained. Adequate suitable habitat at known sites should be maintained including sufficient densities of the species' host plant, crucifer.

Active Period

Flight from second week of June to fourth week of June

Survey Methods

The best way to survey for this species is by conducting visual meander surveys which consists of checking for this species near larval food plants, on adult nectar sources, and in mud puddles.

Visual, aerial net

Survey Period: From second week of May to fourth week of June

Time of Day: Daytime


Survey References

  • Klots, A.B. 1951. Peterson Field Guides: Eastern Butterflies. Houghton Mifflin Company, Boston. 349pp.
  • Martin, J.E.H. 1977. The Insects and Arachnids of Canada (Part 1): Collecting, preparing, and preserving insects, mites, and spiders. Publication 1643. Biosystematics Research Institute, Ottawa.

Technical References

  • Glassberg, J. 1999. Butterflies through Binoculars: The East. Oxford University Press, New York. 242pp.
  • Nielsen, M.C. 1999. Michigan butterflies and skippers: A field guide and reference. Michigan State University Extension Bulletin E-2675, East Lansing. 248pp.