Lycaena epixanthe

Distinguished from similar coppers by its small size and habitat restriction to acid bogs. Purplish copper (Lycaena helloides) is larger with more orange on female upper side and conspicuous orange submarginal line on hind wing in both sexes. Dorcas copper (Lycaena dorcas) is larger with more black spots on male upper side, more orange on female upper side, and pinkish-brown or tan underside with red-orange hind wing submarginal line.

Wingspan 2.2–2.5 cm. Upper side of male wings dark gray-brown with strong purplish sheen that glows intensely under UV light; few black basal spots on forewing; orange markings on hind wing outer margin. Female upper side similar but with lighter purplish iridescence. Underside of wings in both sexes varies from whitish-gray to yellowish-tan.

Acid bogs with cranberries (Vaccinium species). Occupies specialized peatland habitats with acid soil conditions.

North America; recorded from Vermont and other northeastern US states, with range extending through Canada.

Late June to early August; timing varies regionally (mid-June to mid-July near Ottawa, mid-June to early July in New Jersey, mid-June to mid-August in Maine).

Larvae feed exclusively on shrubby cranberries: Large cranberry (Vaccinium macrocarpon) and Small cranberry (Vaccinium oxycoccos). Adults sip dew drops and nectar almost exclusively from cranberry flowers.

• Vaccinium macrocarpon - primary larval hostLarge cranberry
• Vaccinium oxycoccos - primary larval hostSmall cranberry

Univoltine (one brood per year). Egg overwinters, usually under water with fully developed larva inside; egg can withstand flooding. Larva bluish-green with darker green middorsal stripe. Chrysalis pale yellow-green to green with brown and white markings, rarely solid dark purple. Approximately 85% of lifespan spent in egg stage.

Males perch on low cranberry foliage from 10:00 A.M. to 6:00 P.M. to await females. Upon detecting a female, males pursue; after female lands, male lands behind her, vibrates wings, and mating ensues. If female has mated or rejects mating, she vibrates wings and male departs. Females lay eggs singly on underside of host plant leaves a few inches above bog surface. Flight weak and close to ground; difficult to capture due to bog habitat.

Specialized herbivore dependent on cranberry host plants in peatland ecosystems. Serves as indicator species for intact acid bog habitats.

Listed as species of special concern in Connecticut. Conservation focus for acid bog habitat preservation.

• Lycaena helloideslarger size; female has extensive orange on upper side; both sexes have conspicuous orange submarginal line on hind wing upper side
• Lycaena dorcaslarger size; male has more black spots on upper side; female has more orange on upper side; underside pinkish-brown or tan with red-orange hind wing submarginal line
• Lycaena heteroneablue color on upper side and brown on underside (reversed from L. epixanthe)

• BugGuide
• Wikipedia
• GBIF taxonomy match
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• Life history and morphology of the immature stages of the bog copper butterfly Lycaena epixanthe (Bsd. & LeC.) (Lepidoptera: Lycaenidae)
• Flight morphology corresponds to both surrounding landscape structure and local patch conditions in a highly specialized peatland butterfly ( Lycaena epixanthe )