White Admiral, Red-spotted Purple (Limenitis arthemis) (Drury, 1773)
Diagnosis: There are several forms of this species, two so distinct that they were treated as separate species for many years. Subspecies arthemis and rubrofasciata, the White Admiral, have a deep purplish-black ground colour on the upperside, with a broad white band crossing both wings. There isa row of spots, blue with often a small amount of red in arthemis and completely red in rubrofasciata,adjacent to the outer margin of the white band on the hindwing. The underside of both subspecies is pale reddish brown with bright brick-red spots along the outer margin and the near the base; the white bands are repeated on the underside. Subspecies astyanax, the Red-spotted Purple, has the same ground colour on the upperside, but entirely lacks the white bands except in some hybrids where the ranges overlap. The outer part of the hindwing upperside has a greenish iridescence. The underside lacks the white band and is blackish in colour except for the same brick-red spots. The wingspan (47 to 78 mm) is highly variable; smaller specimens occur in the north.
Subspecies: Subspecies arthemis occurs from the east coast to Manitoba. Subspecies rubrofasciataflies from central Manitoba westward; in western Ontario and eastern Manitoba the proportion of red versus blue in the submarginal row of spots changes, with the spots in western specimens being almost completely red. Subspecies astyanax has been recorded in Canada only from southern Ontario east to Hastings County; it mimics the distasteful Pipevine Swallowtail (Battus philenor). Hybrids between subspecies arthemis and subspecies astyanax occur in a zone through central Ontario south of the Canadian Shield, and occasionally also in southeastern Ontario well beyond the range ofastyanax.
Range: Common throughout all provinces, Yukon and the Northwest Territories north to treeline, but rare in southern British Columbia.
Early Stages: The larva is white with greyish-brown areas and resembles a bird dropping when it sits on a leaf. Foodplants include willow (Salix spp.), aspen, and poplar (Populus spp.). Subspeciesarthemis also feeds on birch (Betula spp.), while astyanax feeds on some more southerly trees such as cherries (Prunus spp.) and oaks (Quercus spp.).
Abundance: This is usually a common and sometimes abundant species in most of its range. The Red-spotted Purple is common only in southwestern Ontario, infrequent farther north and east.
Flight Season: The adults fly from June to August, with a partial second generation into September.
Habits: Roads and clearings in wooded areas are where this butterfly is most often seen. They like to sun themselves on leaves or on gravel roads, where they periodically open and close their wings. They are rarely seen on flowers, but congregate on rotting fruit and animal dung.
Remarks: The common name for the white-banded form (White Admiral) and that of the unbanded, mimetic form (Red-spotted Purple) have been used for so many years that it is difficult to use either common name for the species as a whole. For those who prefer a single common name, we propose the name Red spotted Admiral; this would still allow the names White Admiral and Red-spotted Purple to be used for the two distinctive forms of the species. Sometimes Red-spotted Purples with some or all of a white band are seen in the more southern part of its range, and White Admirals with no whitebands are occasionally discovered north of where the Red-spotted Purple is found. These are specimens in which recessive genes produce odd results. They also confirm that the two are forms of the same species. Both subspecies hybridize occasionally with other members of the genus, including the Viceroy (L. archippus).
© 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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