Common Sootywing (Pholisora catullus) (Fabricius, 1793)

Diagnosis: The Common Sootywing is well named; its wings are sooty black in colour, broken only by tiny white spots on the outer part of the forewing. Wingspan: 21 to 28 mm.

Range: Pholisora catullus flies commonly throughout the U.S., except the west coast. It is a permanent resident of Canada only in southwestern Ontario, north to Toronto, and in the southern interior of British Columbia. It occasionally expands its range northwards beyond these areas and may form temporary isolated colonies for a few years.

Specimen collection data

Description of this image follows.
Common Sootywing (Pholisora catullus). Pelee Island, Ont. J. Kamstra

Similar Species: None in Canada.

Early Stages: The larvae are greenish to olive, with tiny raised pale dots, and a black head and prothorax. They live in leaf-nests of the foodplants, various members of the Amaranthaceae, including Tumbleweed (Amaranthus graecizans), and Chenopodiaceae, especially Lamb's Quarters (Chenopodium album).

Abundance: This species is uncommon in most of its Canadian range, but can be locally common in southern Ontario.

Flight Season: There are two generations per year, from late May to September.

Habits: Pholisora catullus flies in various kinds of open areas; in the east it is most common in disturbed areas where Lamb's Quarters is abundant.

Remarks: There were several colonies near Ottawa, in both Ontario and Quebec, in the early 1960s, but the species has not been seen in the area since.

© 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.