McNair Butterfly Area rare Nabokov's blue
DULUTH, MN ------ June 7, 2015 ---- The McNair Butterfly Area is located on national forest system lands within the Superior National Forest near the Langley River, about 20 miles north of Two Harbors, MN. The site is habitat for about 50 species of butterflies, nearly every butterfly, common or rare, found in northeastern Minnesota. One butterfly, the grizzled skipper (Pyrgus centaureae freija), has not been found elsewhere in the state. Another species of greatest interest is the rare Nabokov's blue (Lycaedes idas nabokovi), a subspecies found only at a few dozen locations in the Great Lakes Region. A field assessment by faculty of North Dakota State University in 1993 recommended maintaining the McNair site as a forest opening for rare butterfly species of openlands, and with a special emphasis on Nabokov's blue. The site was purchased by The Nature Conservancy in the 1980s and was later acquired by the USDA Forest Service.
Since acquiring the site, Superior National Forest managers have worked to restore and maintain this important habitat. Beginning in the summer of 1998, crews cut most of the trees and brush that had colonized the McNair opening during the previous decade or two. Forest crews have enlarged the opening to its former size by clearing invading spruce trees. A burn plan for the site identifies seven units within the opening. The general plan has been to periodically burn one or two units within the 15-acre opening to encourage dwarf bilberry and other shrub and herbaceous species that are host plants for other butterflies. The entire opening will not be burned at one time because that may risk killing the butterflies, whether in egg, pupa, larvae, or adult form. Management has also included clearing the understory under widely spaced trees adjacent to the opening to determine if Nabokov’s blue will use that kind of habitat.
The population of Nabokov's blue is monitored annually in mid-July. Changes in vegetation (habitat)is also monitored annually. Additional inventories for dwarf bilberry have been made in the vicinity of the McNair site and several small sites have been located that may offer potential for managing additional habitat for Nabokov’s blue.
The management of the McNair Butterfly Area has been a cooperative project between Minnesota DNR and USDA Forest Service with initial support from The Nature Conservancy.
DNR species profile for Narbokov blue