Figs 9, 140, 198. Map 3
Dianthoecia subdita Möschler, 1860: 363.
Mamestra subdita; Smith 1893a: 129.
Lasionycta subdita; McDunnough 1938: 71.
Anarta membrosa Morrison, 1875a: 101.
Anarta membranosa; Smith 1893a: 294, misspelling.
Lasionycta membrosa; McDunnough 1938: 71.
Type material. Dianthoecia subdita: holotype ♁ [ ZMHB, not examined]. Type locality: Labrador. Anarta membrosa: type lost. Type locality: New Hampshire. The type is presumed lost but the name was synonymized with L. subdita by Lafontaine and Kononenko (1988) based on details of the original description.
Diagnosis. This northeastern species can be identified by a combination of lightgray forewing with black orbicular and reniform spots filled with pale-gray scales, black claviform spot, and mottled distal forewing with a checkered fringe. It is most likely to be confused with L. taigata, also found in northeastern North America, but is readily distinguished from it by differences in the genitalia given in the key to species-groups.
The male digitus bears a stout basal spine. Th ose of the other species in the speciesgroup have a broad basal flange. Females have a rounder corpus bursae and more blunt appendix bursae than the western species.
The CO1 DNA of L. subdita differs by more than 1.8 % from that of L. conjugata (Smith) and L. fergusoni sp. n.
Distribution and biology. Lasionycta subdita is predominantly a subarctic species. It occurs across Labrador, Quebec, and Ontario to Churchill, Manitoba on the west shore of Hudson Bay. A disjunct population is in the White Mountains of New Hampshire. Th e adults are nocturnal and come to light. Th ey have been collected in July.