Plants and Animals
Pyrgus centaureae wyandot Grizzled skipper
Key Characteristics
Upper surfaces are grayish black with white spots; fringes are checkered. Undersurfaces are similarly marked but with more and larger spots and white lines. This species lacks a white spot just below and inward of the forewing cell-end bar. The caterpillar is light green with a reddish cast and covered with fine, short, hairs. The head is blackish brown.
Status and Rank
US Status: No Status/Not Listed
State Status: T - Threatened (legally protected)
Global Rank: G5T1T2
State Rank: S1S2 - Rank is uncertain, ranging from critically imperiled to imperiled
Occurrences
| County | Number of Occurrences | Year Last Observed |
|---|---|---|
| Antrim | 1 | 1985 |
| Cheboygan | 1 | 1935 |
| Crawford | 2 | 1965 |
| Emmet | 1 | 1932 |
| Iosco | 1 | 2012 |
| Montcalm | 3 | 1987 |
| Montmorency | 1 | 1941 |
| Newaygo | 2 | 1986 |
| Oscoda | 1 | 1953 |
| Otsego | 2 | 1988 |
| Presque Isle | 3 | 1997 |
| Wexford | 1 | 1957 |
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.
Habitat
Large open areas in oak-pine barrens, disturbed areas and along trails. Adults have been observed nectaring on bearberry, blueberry, dandelion, wild strawberry, and birdfoot violet. Eggs are laid on wild strawberry.
Specific Habitat Needs
Host plant needed in: Alvar; Oak-pine barrens; Pine barrens.
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
Adequate suitable habitat at occupied sites need to be maintained including sufficient densities of the species' host plant. Maintenance and long-term preservation of the habitats with which this species is associated depends on the promotion of fire (or an equivalent anthropogenic disturbance) as the prime ecological process driving the persistence and establishment of these natural communities. Prescribed burning can be used as a management tool to try to re-establish or replicate natural fire regimes in barrens and prairie systems. In areas where this species or other rare invertebrates occur or are of management concern, burning strategies should allow for ample refugia (e.g., only burning part of the available habitat at a time, burn frequency and intensity, type of fire, etc.) to minimize incidental take or other potential adverse impacts and facilitate effective post-burn survival and/or recolonization . Prior to burning, the locations and extent of habitat use of populations of this species and other rare invertebrates at the site should be determined. Burn management units should be established with special attention to microgeographic variation in the distribution of rare species and their host plants. Unburned patches should be left unburned to provide refugia . Mowing, brush cutting and/or other mechanical manipulations can be used in conjunction with or in place of prescribed burning as management tools for maintaining the habitats used by this species . These activities should be conducted in late fall or winter, if possible, to minimize adverse impacts to rare invertebrates.
Active Period
Flight from first week of May to second week of June
Survey Methods
The Grizzled skipper has one generation per year and overwinters as a pupa in a leaf nest on its host plants. Larvae are present from June to August. In Michigan, adults typically have been observed in May until early June. Adults fly close to the ground so they can be difficult to see. 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 first week of May to second week of June
Time of Day: Daytime
References
Survey References
- 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
- Chapman, K.A., M.A. White, M.R. Huffman, and D. Faber-Langendoen. 1995. Ecology and stewardship guidelines for oak-barrens landscapes in the upper Midwest. Pp. 1-29 in F. Stearns and K. Holland, eds. Proc.of the Midwest Oak Savanna Conference, 1993. U.S. EPA, Internet Pubs. Available: www.epa.gov/glnpo/oak/oak93/chapman.html.
- Cohen, J.G. 2000. Natural community abstract for oak-pine barrens. Michigan Natural Features Inventory, Lansing, MI. 6 pp.
- Comer, P.J. 1996. Natural community abstract for pine barrens. Michigan Natural Features Inventory, Lansing, MI. 3 pp.
- Evers, D.C. 1994. Endangered and Threatened Wildlife of Michigan. The University of Michigan Press, Ann Arbor. 412pp.
- Glassberg, J. 1999. Butterflies through Binoculars: The East. Oxford University Press, New York. 242pp.
- Klots, A.B. 1951. Peterson Field Guides: Eastern Butterflies. Houghton Mifflin Company, Boston. 349pp.
- Michigan Natural Features Inventory. 1995. Forest stewardship training materials for oak-pine barrens ecosystem. Unpublished manuscript. Michigan Natural Features Inventory, Lansing, MI.
- Nielsen, M.C. 1999. Michigan butterflies and skippers: A field guide and reference. Michigan State University Extension Bulletin E-2675, East Lansing. 248pp.
- Opler, P.A. 1981. Management of prairie habitats for insect conservation. Natural Areas J. 1(4):3-6.
- Panzer, R. 1988. Managing prairie remnants for insect conservation. Natural Areas J. 8(2):83-90.
- Schweitzer, D.F. 1989. A review of Category 2 insects in U.S.F.W.S. Regions 3, 4, and 5. U.S. Fish and Wildl. Serv., Unpubl. Rept.
- Stehr, F. W. 1997. Michigan Lepidoptera Survey Sites and Seasonal Occurrence of Michigan's Listed Species Annual Report 1997. 30 pp.+ MI Lepidoptera Survey Data Collection Form