Uncas Skipper (Hesperia uncas) (W.H. Edwards, 1863)
Diagnosis: The veins on the underside of the hindwings are white, and the medial row of white spots is expanded into a continuous or nearly continuous white band that crosses the veins. The females of uncas have larger white spots on the upperside of the forewing than other species, and are a little darker than the males. Wingspan: 24 to 31 mm.
Subspecies: There are three subspecies, but only the nominate subspecies occurs in Canada.
Range: The Uncas Skipper has a wide range throughout the American Midwest, extending into the southern part of the three Prairie Provinces, north as far as Edmonton, Alberta.
Similar Species: The Rhesus Skipper (Polites rhesus) is dark brown with no orange on the upperside, and males lack the black stigma. The white veins beneath distinguish uncas from other Hesperia species. [compare images]
Early Stages: The larva is light brown with a dark dorsal stripe and pale lateral stripes. The head is dark brown with cream-coloured marks on the face. Foodplants include Blue Grama (Bouteloua gracilis) and needlegrass (Stipa spp.).
Abundance: This skipper tends to be uncommon to rare in the northern part of its range; there are no recent records from Manitoba and it may no longer occur there.
Flight Season: Hesperia uncas flies in Canada from mid-June to late July.
Habits: It occurs in short-grass prairie, usually on dry sandy prairie hillsides.
Remarks: This is a wary, fast-flying species, difficult to follow with the eye. Like other prairie skippers, it appears to be declining in numbers as its habitat continues to disappear.
© 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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