Lasionycta mutilata

The L. mutilata species-group contains two similar species from the mountains and coast of northwestern North America. It is characterized by the combination of a dorsoventrally flattened uncus, an S-shaped valve with a 50° lateral bend at the base of the digitus, a large triangular cucullus with a long narrow neck, and a long rod-like digitus. The right side of distal aedeagus bears a raised area with multiple small spines. The vesica is 1.5× as long as the aedeagus and is widest mesially, extends to the right beyond a subbasal bend to end to the right of the aedeagus, and bears 3–6 basal cornuti with sharp central spines arising from a conical base and a distal band of multiple spines oriented perpendicular to the vesica. Th e male antenna is weakly biserrate with diamond-shaped segments, 1.5× as wide as the shaft.

The female genitalia of L. mutilata (Smith) are similar to those of the L. subdita species-group but the posterior ductus bursae is slightly expanded leftward, probably to accommodate the raised area of the aedeagus, while the anterior part lacks an asymmetrical widening. Th e distal appendix bursae is broadly rounded.