Lasionycta frigida

Description. Head – Antenna of male weakly bipectinate and fasciculate; individual segments 2.4× shaft width. Antenna of female filiform and ciliate. Dorsal segments dark gray proximally, white distally. Scape white. Eye normal size. Palpus covered with brownish off-white and few dark-gray scales. Frons covered by pale brown-gray hair-like scales. Top of head with equal mixture of dark-gray and white hair-like scales. Thorax – Vestiture a mixture of hair-like white and gray scales and bifurcate white-tipped gray scales, appearing light gray ventrally and hoary gray dorsally with slightly darker gray lines on prothoracic collar and patagium. Legs with equal mixture of gray and luteous off-white scales. Tarsal segments gray with scattered off-white scales, ringed distally with off-white. Wings – Forewing length: male 12 mm (expanse 26 mm); female 13 mm (expanse 27 mm). Ground color of forewing a mixture of light- to dark-gray, white, and luteous scales, appearing slightly uneven dark gray with faint brown tint. Basal, antemedial, and postmedial lines double, dark gray with pale-gray filling. Basal and antemedial lines undulating. Medial shade dark gray, faint, evident near costa and in cell. Postmedial line moderately scalloped, with darker proximal and faint distal components, mildly excurved near cell, otherwise oblique across wing. Subterminal line pale, sinuous, preceded by prominent dark-gray chevrons between veins forming a nearly continuous dark line across the wing. Spots dark gray. Orbicular spot round, filled with light-gray scales peripherally and a dark-gray ocellus centrally. Reniform spot weakly hourglass shaped, filled with light gray peripherally and dark-gray scales centrally. Claviform spot faint, extending half distance between the antemedial and postmedial lines. Terminal area and fringe slightly darker than remainder of wing, fringe weakly checkered. Ventral forewing pale, slightly luteous gray with darker gray shade along costa and in cell. Markings all similar, dark gray. Discal spot moderately large. Postmedial line scalloped, complete across wing. Marginal band moderately sharply demarcated. Dorsal hindwing slightly brownish off-white with scattered dark-gray scales and dark-gray markings. Discal spot ovoid, prominent. Postmedial line undulating, weakly scalloped, more faint than discal spot and marginal band. Marginal band relatively wide, sharply demarcated. Hindwing fringe light gray proximally, brownish off-white distally. Ventral hindwing slightly brownish off-white with scattered dark-gray scales and darker gray markings than on ventral forewing. Discal spot large, ovoid. Postmedial line solid near anterior margin and fading near anal angle, fainter than ventral forewing postmedial line and other hindwing markings. Marginal band darker, narrower, and more sharply defined than ventral forewing marginal band. Abdomen – Covered with pale-luteous off-white and scattered gray scales, appearing light gray. Male genitalia – (Fig. 154). Genital capsule and aedeagus as in the L. leucocycla species-group and L. leucocycla sub-group descriptions. Valve approximately 5.5× as long as wide. Cucullus typical, corona single except double at apex. Vesica with a single basal cornutus (N = 1). Female genitalia – (Fig. 210). Ovipositor lobe, segment VIII, and bursa copulatrix as in the L. leucocycla species-group description. Corpus bursae approximately 1.4× as long as ductus bursae and 0.6× as wide as long. Proximal appendix bursae relatively bulbous.

Distribution and biology. Lasionycta frigida has a restricted range in the Alberta Rocky Mountains. The habitat is mixed forest in cold microclimates (C. Schmidt pers. comm.). It is nocturnal and comes to light, although one specimen was collected during the day. All specimens are from mid-July. This species is very rare in collections.
The Alberta front ranges where L. frigida occurs harbors the southernmost populations of several arctic and subarctic Lepidoptera suggesting that L. frigida might be a subarctic species. It should be sought farther north in Yukon and Alaska.