Poweshiek Skipperling
Oarisma poweshiek (Parker, 1870)

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Diagnosis: Above, this skipper is very dark brown, with an orange suffusion along the costa. Below, the hindwings are dark greyish, with white-lined veins. Wingspan: 24 to 30 mm.

Range: The Poweshiek Skipperling is known from only a very limited range, in just a few states west and south of the Great Lakes, and in a small area of southeastern Manitoba.

Similar Species: The Garita Skipperling (O. garita). [compare images]

Early Stages: Larvae are light green with a dark green, white-edged dorsal stripe, and six pale lines on each side. They overwinter in the fifth instar, and have seven instars in all (Scott, 1986). Foodplants are sedges, including Slender Spike-Rush (Eleocharis elliptica), in Michigan.

Abundance: This species is locally common.

Flight Season: There is one generation per year, with records ranging from 23 June to 8 July in Manitoba.

Habits: Oarisma poweshiek is an inhabitant of moist virgin tall-grass prairie.

Remarks: This species has been reported from Canada in the past, but the early reports were all misidentified Garita Skipperlings. In July 1985 it was found to be locally abundant near Vita, Stuartburn, and Gardenton in southeastern Manitoba (Catling and Lafontaine, 1986). Like many other prairie species, it is reported as becoming scarcer and in need of protection. The truth is that it is the habitat that is becoming scarcer; where the habitat is in good shape, the butterfly is common. This skipper was described from Grinnel, Iowa, and stated to be named after the county in which it had been collected [Poweshiek County]. The name was misspelled "powesheik" in the original description; however, since it is a clear case of an original incorrect spelling it can be corrected (rule 32(c)ii of the International Code of Zoological Nomenclature).

© 2002. This material is reproduced with permission from The Butterflies of Canada by Ross A. Layberry, Peter W. Hall, and J. Donald Lafontaine. University of Toronto Press; 1998. Specimen photos courtesy of John T. Fowler.

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