Lasionycta quadrilunata subsp. yukona Lafontaine (Beartooth Plateau 1986

Lasionycta quadrilunata yukona Lafontaine

Figs 55, 56, 167, 223. Map 14

Lasionycta quadrilunata yukona Lafontaine, 1986: 264.

Subspecies yukona is a darker than the nominate subspecies and the maculation is muted by the darker ground color and the lack of pale shading. Some specimens are more olive gray and resemble subspecies quadrilunata, but the maculation is still more muted. Lasionycta q. yukona can appear similar to L. subfumosa, which occurs in the arctic in western Northwest Territories and northern Alaska, in having a relatively unmarked gray forewing. Differences between these species are listed under L. subfumosa. Farther south L. q. yukona is only likely to be confused with L. lagganata that occurs in the Alberta Rocky Mountains. The two species can be differentiated without dissection by the shape of the antemedial line, irregular in L. q. yukona, ill defined but straight in L. lagganata. In the male genitalia, L. q. yukona has a broadly triangular digitus and a small rounded cucullus. Th e digitus of L. lagganata is much longer and the cucullus is large and triangular.

Records of this subspecies are from the Alaska Range, southwestern Yukon, the Alberta Rocky Mountains, and the Beartooth Plateau in Montana. It flies over fine shale scree tundra and feeds on nectar on a Saxifraga species at Prospect Mountain, Alberta (BC. Schmidt, pers. comm.). Most specimens have been collected during the daytime, but they are also collected uncommonly at night by light trapping (D. Macaulay pers. comm.).

Th e CO1 sequences of the two L. quadrilunata subspecies differ by 0.16 %.