Zebra Swallowtail Eurytides marcellus (Cramer, 1777)

Diagnosis: This rare stray and occasional breeder in Canada has a unique appearance. The longwings are banded lengthwise in greenish white and brown and have the longest tails of any butterfly in North America. The spring form is generally lighter in appearance, owing to narrower black bands, than the summer form. Wingspan: 52 to 70 mm.

Subspecies: There are no subspecies, although the summer form has been given the name "lecontei".

Range: This is a butterfly of the eastern U.S., ranging into Canada only in southern Ontario east to Toronto. It is most often seen along the north shore of Lake Erie.

Similar Species: None in Canada.

Early Stages: The larva is unique in appearance in Canada, coloured green with cross-stripes of black and yellow. It feeds on Pawpaw (Asimina triloba), a rare plant in Canada.

Abundance: Earlier in this century, the Zebra Swallowtail was likely a regular breeder in Canada, as it was sometimes seen in large numbers. In more recent years, it has been seen only sporadically (Wormington, 1983, 1989). A breeding colony near Harrow, Ontario, persisted for several years, but disappeared in the early 1990s.

Flight Season: In the northern part of its range, this butterfly has two flights: the first in April and May, the second from mid-June to mid-August. At Point Pelee, Wormington (1983) records it from mid-June into early August, with one individual reported in early September.

Habits: Rich bottomlands in the vicinity of Pawpaw are the usual habitat of resident populations of marcellus, as well as adjacent fields and roadsides. It flies very rapidly, stopping occasionally to sip nectar with wings continually beating.

Remarks: Although spread specimens are obviously swallowtails, on the wing this butterfly can often appear more like a pale sulphur.

© 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.