1 Forewing an even, translucent grey, without transverse bands; width of male valve at midpoint greater than ¼ total length of valve; vesica with two clusters of spines, one at apex and one at base; female corpus bursae slightly constricted medially.................................................................... D. kononenkoi
– Forewing with light and dark transverse bands; width of male valve at midpoint ¼ or less total length of valve; vesica with single apical cluster of spines (Figs. 6, 7); numerous smaller peg-like spinules may also be present (Fig. 6); female corpus bursae oval, wider posteriorly than anteriorly........................ 2
2 Forewing transverse bands meeting posterior margin at right angles; known only from dry, rocky tundra habitat in the Yukon (male unknown) ............. ................................................................................................. D. verticalis
– Forewing transverse bands meeting anal margin at acute angle, running more or less parallel to outer margin; occurring in wet tundra and boreal peat bogs ............................................................................................................ 3
3 Forewing and thorax markings varying from nearly unmarked to moderately contrasting (subapical pale dash always contrasting), but never with basal and antemedial area paler than outer half of wing (Fig. 1); male valve apex with two short, blunt projections ( Fig. 4); juxta wider than long ( Fig. 4a); inflated vesica approximately as long as aedeagus (Fig. 6)......................... D. albertae
– Forewing and thorax contrastingly marked in mouse grey and whitish-grey banding, with basal and antemedial area noticeably paler than outer half of wing (Figs. 2, 3); male valve apex strongly bifurcate, with 2 longer narrower prongs ( Fig. 5); juxta longer than wide ( Fig. 5a); inflated vesica 2/3 or less length of aedeagus (Fig. 7) ........................................................ D. tarandus