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Phyciodes mylitta Hübner, [1819]
Crescents; Mylitta Crescent
Family: Nymphalidae (Brushfoots)
Species account authors: Crispin Guppy and Jon Shepard.
Extracted from Butterflies of British Columbia.
Introduction to the Lepidoptera of BC
Introduction to the Butterflies of BC
The Families of Lepidoptera of BC

Photograph

© Norbert Kondla     (Photo ID #6406)

Map

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Distribution of Phyciodes mylitta in British Columbia.
(Click on the map to view a larger version.)
Source: Butterflies of British Columbia by Crispin Guppy and Jon Shepard © Royal BC Museum

Species Information


Adult

The Mylitta Crescent is very similar to the Pale Crescent but much smaller. The pattern on the underside is less crisp.

Immature Stages

The egg is pale green when laid, but changes to dark grey before the larva emerges. It is 0.50 mm across. The mature larva has a shiny black head. The body is dull black with a dark dorsal line and white spots on the anterior base of prominent hairy spines. The spiracular band consists of two thin yellow lines (Hardy 1964).

Subspecies

BC populations are the nominate subspecies, P.m. mylitta (W.H. Edwards, 1861) (TL: San Francisco, CA), which occurs everywhere except the extreme southern end of the species range, where several disjunct sets of populations have been given subspecies status.

Genus Description


The name Phyciodes may come from the Greek phykos (painted or "covered with cosmetics"), in reference to the complex ventral wing pattern. The common name "crescents" (Gosse 1840) refers to the crescent-shaped spot in the centre of the ventral hindwing margin.

Phyciodes in the limited sense used here is separated from the Neotropical genera Anthanassa Scudder and Eresis Boisduval by the presence of two to four in-curved hooks on the posterior tip of the tegumen of the male genitalia. The saccus is present in the male genitalia. The genus is Nearctic and contains nine species. The larvae of BC species feed on asters (Aster) or thistles (Cirsium).

Biology


There are two generations of the Mylitta Crescent, one flying in late April and May and the other in July and August. Hardy (1964) reared the newly established Vancouver Island populations of the Mylitta Crescent on Cirsium arvense. The larvae produced by the second-brood adults hibernated as fourth instar larvae on Vancouver Island.

Habitat


The Mylitta Crescent occurs across southern BC in the xeric habitat of the Pale Crescent, but also in more mesic habitat on Vancouver Island, the Lower Mainland, and the West Kootenay. At least on Vancouver Island (Hardy 1962a; Shepard 1977), the Mylitta Crescent was not present prior to European settlement, and was not recorded until the 1950s. There are also no Lower Mainland records before 1902 or before the introduction of Canadian thistle. This is the only known larval foodplant on Vancouver Island or the Lower Mainland, where the Mylitta Crescent is seen only in disturbed habitat. Thus the species may also not be native to the Lower Mainland.

Distribution

Distribution

The Mylitta Crescent ranges from southern BC south to Baja California and Sonora, MEX.

Status Information

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



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