Lasionycta quadrilunata (Grote)

Figs 54–56, 166, 167, 222, 223. Map 14

Anarta quadrilunata Grote, 1874b: 244

Lasiestra quadrilunata; McDunnough 1938: 71.

Lasionycta quadrilunata; Lafontaine et al. 1986: 263.

Lasionycta quadrilunata yukona Lafontaine, 1986: 264 .

Type material. Anarta quadrilunata: holotype ♀ [USNM, examined]. Type locality: Colorado Territory. Lasionycta quadrilunata yukona: holotype ♀ [CNC, examined]. Type locality: 17 km WNW Burwash Flats, Yukon.

Diagnosis. Lasionycta quadrilunata is an alpine species characterized by a large hindwing discal spot, a short broad digitus resembling an obtuse triangle, and a small rounded cucullus bearing a corona of four rows of setae. Th e forewing is light gray or slate gray with a yellow or olive tint. Th e dark-gray transverse lines are prominent but the spots are indistinct. Th e female bursa is similar to that of L. staudingeri but L. quadrilunata has an increased number of short setae on abdominal segment VIII, similar to L. lagganata .

The male antenna of quadrilunata is weakly biserrate, almost beadlike (1.4× the width of the central shaft).

Distribution and biology. Records of L. quadrilunata form an arc on a map, from south-central Alaska down the spine of the Rocky Mountains to Colorado. It flies over scree tundra and is diurnal. The flight period is from mid-July to early August.

Geographical variation. The populations of L. quadrilunata are arranged in two subspecies.