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Euphydryas editha beani Scudder, 1872
Bean's Checkerspot; Checkerspots
Family: Nymphalidae (Brushfoots)
Species account authors: Crispin Guppy and Jon Shepard.
Extracted from Butterflies of British Columbia.
Introduction to the Butterflies of BC
The Families of Lepidoptera of BC

Photograph

© Jeremy Gatten     (Photo ID #6116)

Map

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Distribution of Euphydryas editha beani in British Columbia.
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Source: Butterflies of British Columbia by Crispin Guppy and Jon Shepard © Royal BC Museum

Illustration

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Illustration 2

Illustration Source: : Butterflies of British Columbia by Crispin Guppy and Jon Shepard © Royal BC Museum

Species Information


Adult

The dorsal arm of the harpe of the male genitalia is covered with small spines, a unique character for BC Euphydryas species. For a further description, see the "Adult" discussion under Anicia Checkerspot.

Immature Stages

Emmel and Emmel (1973) describe the immatures in California. The egg is yellow. The mature larva is black; the dorsal and lateral lines are orange, not white as for the Chalcedon Checkerspot.

Subspecies

The Vancouver Island populations are Taylor's Checkerspot, E.e. taylori (W.H. Edwards, 1888) (TL: Victoria [Beacon Hill], BC). This subspecies ranges south to the southern Willamette Valley, OR, but is now nearly extirpated from Oregon and Washington. The interior subspecies is Bean's Checkerspot, E.e. beani (Skinner, 1897) (TL: Laggan [vicinity Lake Louise], AB). This subspecies ranges south to northern WA, northern ID, and northwestern MT.

Genus Description


The name Euphydryas is derived from the Greek euphys (a goodly shape) and dryas (a dryad or wood nymph) (Emmet 1991), hence these checkerspots are goodly shaped wood nymphs. The common name "checkerspots" is derived from the checkerboard pattern of the upperside of the wings.

The Euphydryas checkerspots differ from Charidryas checkerspots by having brick red, not tawny, spots alternating with the black spots. The male genitalia lack the saccus. This is a Holarctic genus, with five Nearctic species and four Palearctic species. None of the individual species are Holarctic. The larvae feed on a variety of plants. Adults of three western North American species, all of which are in BC, are very hard to distinguish without reference to the male genitalia. These three species are in the subgenus Euphydryas (= Eurodyras Higgins = Occidryas Higgins). The fourth BC species, E. gillettii, is in the subgenus Hypodryas. All species worldwide are in one or the other of the two North American subgenera.

The figure illustrates the one part of the male genitalia, the harpe, that is diagnostic for species. The short arms of the harpe, one rounded and toothed and the other flattened out, are diagnostic for the subgenus Hypodryas. In the subgenus Euphydryas, at least one arm of the harpe is longer than the body of the harpe. This subgeneric classification is supported by recent DNA analysis of worldwide Melitaeinae by Zimmermann et al. (2000), who prefer subgenera to genera. Once this paper has been examined closely, however, others may choose to recognize two genera instead of one for the North American fauna.

Biology


Low-elevation populations on Vancouver Island fly from mid-April to mid-May. Interior alpine populations fly from late June to early August. Danby (1890) first observed the larvae at Beacon Hill Park on the flats above the sea cliffs. They were feeding on the introduced rib-wort plantain, Plantago lanceolata. The larvae feed until the fourth or fifth instar, and then hibernate until the following spring, when they mature, pupate, and emerge as adults by mid-April (Shepard 2000a). In 1972 Shepard (2000a) found larvae from the Hornby Island population feeding on the native plantain, P. maritima, as well as P. lanceolata. The adults on Hornby Island utilize spring gold, Lomatium utriculatum, as the primary nectar source (Shepard 2000a). At the site of the Beacon Hill and Uplands Parks extinct populations, there are virtually no spring gold plants left, but the introduced rib-wort plantain is still plentiful. Thus the loss of an adult nectar source is probably the most important reason for extinction.

Parmesan (1996) conjectured that BC populations have become extinct because of global warming. All but one of the extinct populations, however, became extinct well before global warming was a significant phenomenon. The last to become extinct, in the early 1990s, did so because its habitat was overrun by Scotch broom (CSG). This habitat was a powerline right-of-way that had been kept clear as a Christmas tree farm. After the tree farm was abandoned, BC Hydro adopted a policy of encouraging Scotch broom growth to reduce tree regeneration under powerlines. The one healthy population is on Hornby Island, where there is no significant Scotch broom. The local community is monitoring Scotch broom so that it does not invade the habitat of Taylor's Checkerspot.

Habitat


Edith's Checkerspot occurs in two distinct areas of the province. One area is on southeastern Vancouver Island in lowland dry meadows near sea level. The Vancouver Island populations have been reduced to one known population on Hornby Island. The other area is at and above timberline in the Southern Interior and the Kootenays.

Distribution

Distribution

Edith's Checkerspot occurs from southern BC south to Baja California, UT, and western CO.

Status Information

Origin StatusProvincial StatusBC List
(Red Blue List)
COSEWIC
NativeS5YellowNot Listed



BC Ministry of Environment: BC Species and Ecosystems Explorer--the authoritative source for conservation information in British Columbia.

General References