Comprehensive DescriptionRead full entry
General DescriptionA medium-size (2.8-3.0 cm wingspan) broad-winged moth. The forewings of the male are blue-grey, with contrasting black antemedian and postmedian bands, the former bleeding outward into the median area along its upper half. The terminal band and fringe are dark grey. The hind wings are pale buff-orange, with prominent and slightly sinuous dull black post median, sub terminal and terminal bands and a pale fringe. There is a dark discal spot, and dark scaling running from the basal area to the post median band. Sexes similar, but females are browner and less sharply marked. Most likely to be mistaken for a Drasteria (petricola or hudsonica), but annexa has three narrow bands crossing the hindwing, whereas Drasteria have two wider and more sinuous ones. Other Alberta Caenurgina (erechtea and crassiuscula) are larger, paler in color or have less contrasting patterns. The ventral surface in particular is prominently banded in annexa and unmarked or at best faintly banded in the others.