Figs 12, 13, 143, 201. Map 4

Mamestra mutilata Smith, 1898: 246.

Lasionycta mutilata; McDunnough 1938: 71.

Mamestra rainieri Smith, 1900: 462, syn. n.

Mamestra rainierii; Dyar 1903: 156, misspelling.

Lasionycta rainieri; McDunnough 1938: 71.

Type material. Mamestra mutilata: holotype ♁ [USNM, examined]. Type locality: British Columbia. Mamestra rainieri: holotype ♁ [USNM, examined]. Type locality: Mount Rainier, Washington.

Diagnosis Lasionycta mutilata is a distinctive species from northwestern North America. It has a mottled silver-gray forewing with black lines and spots and patches of yellow green in the fold and distal to the subterminal line. The orbicular, claviform, and reniform spots are large and filled with the ground color. Adults are most similar to non-melanic specimens of L. haida, but can be identified by its gray ventral thorax, dark gray brown in L. haida. Lasionycta mutilata is shinier and bluer than L. haida and its spots are larger. Th e male genitalia and antennae of the species are indistinguishable. Th e species are easily distinguished by locality since L. haida occurs on the Queen Charlotte Islands.

Th e CO1 sequences of L. mutilata and L. haida differ by 1.55 %.

Distribution and biology. Lasionycta mutilata occurs from Oregon and Yellowstone National Park, Montana / Wyoming northward to the Alaskan Panhandle and the Rocky Mountains of Alberta. It is absent from the Queen Charlotte Islands. Lasionycta mutilata flies in high transition zone and subalpine conifer forest and is nocturnal. It has been collected from late June through August.

Geographical variation. Lasionycta mutilata has a nearly uniform appearance throughout its range. Some specimens from Ketchikan, Alaska are darker than those from elsewhere, but none shows the brown color characteristic of L. haida.