1 Punctation of head and pronotum not asperate. Pronotum and elytra usually much lighter than head and abdomen. Apex of median lobe wide, less than 2 times as long as wide (Figs. 25 –27, 55–57, 64– 65).Nearctic species................................................. 2
– Punctation of head and pronotum asperate. Body dark brown, pronotum and elytra almost as dark as head and abdomen. Apex of median lobe long and narrow, 2.5 times as long as wide (Figs. 72–73). Palaearctic species. Body length 3.6 –4.0 mm........................................................................................................ 4. L. lateralis (Mannerheim)
2. Pronotal width to length ratio 1.2–1.3. Apex of median lobe (in parameral view) broadest at the base, not constricted (Figs. 64–65). No projections at the base of the apex (Figs. 64–67). Spermatheca larger, its proximal loop wider, almost circular (Fig. 70). Body length 3.8–4.6 mm, pronotal length 0.71–0.89 mm, pronotal width 0.90– 1.09 mm. Distributed in interior Canada and eastern North America (Fig. 71).......................................................................................................... 3. L. franclemonti Hoebeke
– Pronotal width to length ratio 1.3–1.4. Apex of median lobe (in parameral view) constricted basally (Figs. 25 –27, 33–35, 55– 57), with dentiform projection on each side of the apex base (Figs. 25 –29, 55– 59). Proximal loop of spermatheca narrower, with parallel sides (Figs. 32, 40, 48) or spermatheca smaller (Figs. 62–63).............................. 3
3. Dentiform projections at the base of the apex of median lobe longer and sharper (Figs. 25–29). Body larger (body length 3.9–4.4 mm, pronotal length 0.64–0.74 mm, pronotal width 0.91–1.04 mm). Three subspecies known from Alaska, British Columbia, Yukon Territory, and mountains of the western and northeastern North America (Fig. 18).................................................................................................. 1. L. angularis (Mäklin)
– Dentiform projections at the base of the apex of median lobe shorter and blunter (Figs. 55–59). Body smaller (body length 3.2–3.5 mm, pronotal length 0.60–0.66 mm, pronotal width 0.81–0.87 mm). Known only from the Riding Mountains National Park, Manitoba (Fig. 18)............................................... 2. L. manitobae Gusarov, sp. n.