Eastern Comma (Polygonia comma) (Harris, 1842)
Diagnosis: Although quite variable, this medium-sized (wingspan: 37 to 56 mm) species is usually a dark orange brown with black borders and distinct black spots on the upperside. There are two forms: the winter form is described above; the summer form has almost entirely black hindwings above, often with a violet edging as in the Question Mark (P. interrogationis). The underside in males is mottled in various shades, but females have a relatively even grey-brown or yellow-brown underside. The silver comma-shaped mark has a swollen club at each end.
Range: Widespread in eastern North America, the Eastern Comma is found across eastern and central Canada from St. John's, Newfoundland, to southeastern Saskatchewan. There is one Alberta record, at Turner Valley.
Similar Species: The dark form of comma is frequently confused with the dark form of the Question Mark, but the two can readily be distinguished by the shape of the comma mark on the underside. The pale form is easily confused with the Satyr Comma (P. satyrus), which usually occurs north and west of the Eastern Comma's range. They can be distinguished by the upperside colour, which is orange brown in comma and tawny yellowish brown in satyrus; by the underside pattern, which tends to bemottled in comma but appears to be more longitudinally streaked in satyrus; and by the row of pale submarginal spots on the hindwing upperside, which tend to be separate and surrounded by dark shading in comma, but are larger and tend to run together into a pale band in satyrus. [compare images]
Early Stages: The larvae have two colour forms: greenish white and greenish brown. There are rows of yellow or white spines running down the body. The larval foodplants are mainly stinging nettles(Urtica spp.), Wood Nettle (Laportea canadensis), elm (Ulmus spp.), and Hops (Humulus lupulus).
Abundance: Generally uncommon, the Eastern Comma is rarely seen in numbers. However, in most of its Canadian range, it is one of the most regularly seen commas. It tends to be more common in the second generation in late summer and fall. The Eastern Comma and the Question Mark are associated with gardens and waste places more than any other anglewings.
Flight Season: This double-brooded butterfly can be seen on the wing in its Canadian range any timefrom April through to mid-October. The short-lived dark summer brood emerges in June, the second generation in August.
Habits: The Eastern Comma is a butterfly of moist woodlands, generally seen in clearings or along edges and roadsides. It likes to feed on sap running from trees and sometimes alights on the ground, usually with the wings closed. If disturbed, it will often alight on a tree trunk or limb and sit upside down with its closed, leaf-shaped wings giving it perfect camouflage.
Remarks: All anglewings are difficult to identify, particularly in the spring when they are usually worn. Some historical Canadian reports of these species outside their usual range were based on misidentifications.
© 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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