Karner Blue (Lycaeides melissa samuelis)

Overview

Species Overview

Karner blue (Lycaeides melissa samuelis), butterfly listed as Federally Endangered and Special Concern in Wisconsin, has been found in pine barrens and oak savanna in close association with its larval hostplant lupine (Lupinus perennis). In Wisconsin, also found along utility and road right-of-ways, abandonded agricultural fields, and managed forests. This butterfly has two flight periods: adults are present from late May through late June and again from late July through late August.

Status and NHI Documented Occurrences in Wisconsin

The table below provides information about the protected status (State and Federal Status) and the rank (S and G Ranks) for Karner Blue (Lycaeides melissa samuelis). See the Working List Key for more information about the abbreviations used. Counties shaded blue have documented occurrences for this species in the Wisconsin Natural Heritage Inventory database. For invertebrates, dots depict locations from the "Invertebrate Atlas," a database with occurrences of rare and common aquatic and select terrestrial invertebrate species found in Wisconsin and adjacent areas. While the invertebrate atlas is a quality assured database, not all records have been verified. The map is provided as a general reference of where this species has been found to date and is not meant as a range map.

Summary Information
State Status:	SC/FL
Federal Status in Wisconsin:	LE
State Rank:	S3
Global Rank:	G5T2
Tracked by NHI:	Y
Species of Greatest Conservation Need:	Y

Documented locations of Lycaeides melissa samuelis in the Natural Heritage Inventory Database as of April 2009.

Detailed Information

Identification: Adult males are bright blue above with very thin black margins and a white fringe. Females are blackish-brown above with varying amounts of blue basally, with a row of submarginal black spots capped with orange on the hindwing. The wings below of both sexes are pale gray marked with black spots and a submarginal row of pale blue iridescent spots capped with orange. Easily confused with other species of blues. Both upper and undersides must be closely examined to correctly identify this species. Wingspan 25-28mm. Length of forewing 13-14mm. Eggs are pale greenish-white, flattened, about 0.7 mm in diameter. Mature larvae are slug-like in shape, bearing fine hair. They are pea-green with a brown-black head capsule and marked with pale green lateral stripes and a dark green dorsal stripe.

Similar Species: Northern Blue (Lycaeides idas nabokovi) is very similar, and is difficult or impossible to distinguish. In Wisconsin, the Northern Blue tends to be a bit larger. In males the black marginal border of the hindwing is toothed inward between the veins. Female Nabokov’s Blues usually have more extensive blue above and have much less submarginal orange on the hindwing. Karner blue and Nabokov's blue ranges do not overlap in Wisconsin except perhaps in Oconto and Menominee County.

Habitat: Pine barrens and oak savanna in close association with its larval hostplant. In Wisconsin, also found along utility and road right-of-ways, abandonded agricultural fields, and managed forests. A common feature of Karner habitat is a range of canopy cover from nearly full sun to semi-closed canopy with patchy openings - conditions that allow full sunlight to reach the the low-growing lupine plants. Lupine grows best in sandy soils and full sun where competition from shrubs and tall grasses is minimal. It spreads quickly in areas recently cleared by fire, logging, grazing, or other disturbance.

Nectar Source: At least 69 species in Wisconsin: Blazing-star (Liatris spp.), butterflyweed (Asclepias tuberosa), flowering spurge (Euphorbia corollata), goldenrod (Solidago sp.), spotted knapweed (Centaurea biebersteinii), rock cress (Arabis lyrata), and wild lupine.

Host Plant: Wild lupine (Lupinus perennis).

Associated Species: Persius duskywing (Erynnis persius) and frosted elfin (Callophrys irus) occur earlier in the season in the same habitat type, and use wild lupine as their larval host. The silvery blue (Glaucopsyche lygdamus couperi) also occurs or would be expected in many Karner blue sites.

State Distribution: Local but sometimes common in stands of its hostplant. Adams, Burnett, Chippewa, Clark, Douglas, Dunn, Eau Claire, Jackson, Juneau, Marquette, Menominee, Monroe, Oconto, Outagamie, Polk, Portage, Sauk, Shawano, St. Croix, Waupaca, Waushara and Wood counties.

Global Distribution: The nominate subspecies, L. melissa melissa, is widespread throughout much of the western USA and adjacent Canadian provinces. L. melissa samuelis, the eastern subspecies to which Midwest populations belong, occurs from Wisconsin east through New York, with most presently remaining populations in Wisconsin and Michigan.

Threats: Loss of habitat and hostplant due to woody species and closed forest encroachment. Overwintering eggs are exposed and vulnerable to being killed by fire. Larvae are likely to be impacted by Bt spraying for gypsy moth control. Lupine can be seriously impacted in drought years, to the point of being in too poor a condition for the second brood larvae to successfully mature.

Phenology: Adults are present from late May through late June and again from late July through late August.

Life History: Bivoltine. Larvae hatch from overwintering eggs by late April, mature by late May, pupate and emerge as first brood adults, which begins another cycle producing adults by late July. Eggs are laid on or near the hostplant. Eggs hatch in about one week, larvae then feed on lupine for three weeks and pupate. The chrysalis is suspended on lupine stems or deposited in the leaf litter. Late stage larvae have a mutualistic relationship with ants. Specialized glands secrete a liquid that is harvested by the ants. In turn, the ants protect the larvae from various predators, and in some cases, increase larval survival significantly (Wisconsin Karner Blue HCP). A remnant-dependent species.

Survey Guidance: See the Karner Blue Butterfly Habitat Conservation Plan for details.

Inventory, Monitoring and Research Needs: Monitor known populations, particularly in sites managed with fire.

Additional Information: See the Karner blue Habitat Conservation Plan.

Management Guidance: Sites managed with fire should be divided into several burn units and include refugia. Carefully done logging can be beneficial to Karner Blues, and thinning but not clear cutting encroaching stands of pine and oak is strongly recommended. Curtail roadside mowing of lupine stands when early stages are on the plant and when mowing will set back flowering.

Information originally presented as part of the Online Field Guide to Rare Lepidoptera: Bogs and Barrens.

Photos

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