E-Fauna BC: Electronic Atlas of the Wildlife of British Columbia

Oeneis macounii Hübner, [1819]
Arctics; Macoun's Arctic
Family: Nymphalidae (Brushfoots)
Species account authors: Crispin Guppy and Jon Shepard.
Extracted from Butterflies of British Columbia
The Families of Lepidoptera of BC
Introduction to the Butterflies of BC
Photo of species

© Norbert Kondla  Email the photographer   (Photo ID #8094)

E-Fauna BC Static Map
Distribution of Oeneis macounii in British Columbia
Details about map content are available here.

Species Information


Adult

Macoun's Arctics are large, golden brown butterflies with dark wing borders. They have two eyespots on the dorsal forewing and one on the dorsal hindwing. The ventral hindwings are grey brown, and have a distinct band crossing the wing. Males do not have a large dark stigma covering the forewing discal cell. In females the dorsal forewing is only lightly dusted with grey scales near the wing base, usually less than one-quarter of the discal cell.

Immature Stages

Eggs are round and white, slightly flattened on the top and bottom. There are 17-21 vertical ribs. First instar larvae are grey green with two short subconical tails. The longitudinal lines are red brown, the basal ridge is buff with a brown line below it, and the head, underside, legs, and prolegs are green yellow. Mature larvae are brown buff. The dorsal stripe is pale black, the lateral band is black with a green under colour, the spiracular band is green buff, the basal ridge is clear buff, and the underside, legs, and prolegs are grey green (Beutenmüller 1889; Edwards 1887-97).

Subspecies

None. The type locality of the species is Lake Nipigon, ON.

Genus Description


The name Oeneis refers to Oeneus, king of the ancient city of Calydon in western Greece, husband of Althaea and father of Meleagr and Tydeus. The name of the European genus Melanargia is derived from Meleagr, and another species of Satyrinae was derived from Tydeus. The common name "arctics" was first used by Holland (1898) in reference to the arctic and alpine distribution of many species.

Arctics are medium-sized brown or grey butterflies. They usually have eyespots on the wings. They fly rapidly and erratically over short distances, and then drop suddenly to the ground or onto a tree trunk. Arctics all have a two-year life cycle, with the young larvae hibernating the first winter and the almost mature larvae hibernating the second winter. The two-year life cycle results in many species having adults in flight only every second year, with butterflies in alternate years being greatly reduced in abundance or missing entirely in some or all areas.

Eggs are white or off-white in colour, and are conical in shape, with vertical ribs down the side. First instar larvae are thinly covered with hairs, and are tan or greenish. Mature larvae are slender and are tan or greenish with longitudinal stripes of various colours down the back and sides. They are thinly covered with hairs that are frequently reddish in colour. Pupae are roughly cylindrical and rounded, and have brown,yellow brown, and olive markings. Descriptions of the immature stages are all from outside BC, with the exception of the Great Arctic.

Larval foodplants are usually grasses and sedges. One species, the Jutta Arctic, also feeds on rushes. Eggs are laid singly on leaves of the foodplant, or nearby on dead leaves or debris. The foodplants naturally utilized in BC are not known for any species; the little information that is available is from Manitoba, Alberta, or the American Rocky Mountains.

Arctics fall into three basic ecological groups (Masters 1969): forest-dwelling species (macounii, nevadensis, jutta); prairie and steppe species (uhleri, chryxus, alberta); and arctic taiga-tundra/alpine summit species (bore, melissa, polixenes). Oeneis bore and polixenes can sometimes be difficult to identify by wing pattern alone, but the valves of the male genitalia are distinctly different. Oeneis rosovi is also difficult to distinguish from O. polixenes, but there are no genitalic differences between the two species.

Biology


Macoun's Arctics fly in June and July, usually in even years in BC but in odd years in the Peace River and near Bridge Lake. They have a biennial life cycle that produces adults only once every two years. In the boreal forests of Alberta, they fly only in odd-numbered years (Masters and Sorensen 1969; Masters 1974). From Alberta to central Ontario they occur primarily in association with jackpine.ln BC they occur in open lodgepole pine and Douglas-fir forests. The natural larval foodplants are unknown, but in captivity the larvae feed on grasses and sedges.

Females fly slowly and aimlessly through pine forests, while. males actively defend territories in small forest clearings. A male perches on a tree branch or on top of a bush and patrols the clearing, darting at other butterflies when they come near, to drive away males and court females. When a male is captured, a new one frequently replaces him, using the same perch to defend the territory. Territories usually contain a few flowers used as nectar sources (Masters and Sorensen 1969). Near Kelowna a male used the top of a broken stump as a perch, in an opening in a lodgepole pine forest on a hilltop (CSG).

Habitat


Macoun's Arctics occur in widely scattered localities from the Southern Interior of BC north to the Alaska Highway. They inhabit open pine and fir forests, especially thinly forested hilltops.

Distribution

Distribution

Macoun's Arctics are found from BC east across the boreal forest regions of CAN to southern PQ, entering the USA only in MN and MI.

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.

Additional Photo Sources

General References


Recommended citation: Author, Date. Page title. In Klinkenberg, Brian. (Editor) 2021. E-Fauna BC: Electronic Atlas of the Fauna of British Columbia [efauna.bc.ca]. Lab for Advanced Spatial Analysis, Department of Geography, University of British Columbia, Vancouver. [Accessed: 2024-10-03 6:23:41 AM]
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