Key to the Lesteva species known from South Siberia

1 Appendages slightly elongate, shoulders not reduced; body smaller (2.4–4.0 mm) ................................... 2

- Appendages strongly elongate, shoulders reduced; body larger (4.1–5.6 mm)........................................... 3

2 Pronotum strongly transverse, with impressions; body larger (4.0 mm), dark brown; antennae reddish brown; habitus and aedeagus as in Shavrin (2000, Figs. 8–9, 19); Khamar-Daban mountain range .......... ......................................................................................................................................... L. czerskyi Shavrin

- Pronotum slightly transverse, without impressions; body smaller (2.4–3.0 mm), pale brown; elytra reddish brown to brown, sometimes with light yellow spots on shoulders; antennae yellow; habitus and aedeagus as in Shavrin (2000, Figs. 10–11, 20); Irkutsk and Chita Territories, Republic of Buryatia ........................ ............................................................................................................................ L. cordicollis Motschulsky

3 Body and appendages dark brown; elytra long (LE:WE=89:31), with fairly long grey setae; habitus as in Fig. 1; aedeagus (Figs. 11–12) small, median lobe with short triangular apex; Barguzin mountain range .. ...................................................................................................................................... L. barguzinica sp.n.

- Body muddy-brown or yellowish-brown, appendages paler; elytra shorter, with shorter, denser goldish setae; aedeagus larger .................................................................................................................................. 4

4 Elytra short (LE:WE=90:39), strongly widened to apex; habitus as in Fig. 4; first metatarsal segment visibly shorter than last; ocelli poorly developed; median lobe of aedeagus (Figs. 13– 14) in lateral view with beak-like bent apex; East Sayan ............................................................................... L. brathinoides Zerche

- Elytra longer (LE:WE=(92–97):(28–34)), less widened to apex; first metatarsal segment shorter than last; ocelli developed or reduced; median lobe of aedeagus with pointed apex ................................................. 5

5 Ocelli well developed; habitus as in Fig. 3; aedeagus as in Figs. 15–16; West Sayan. L. sajanensis Zerche

- Ocelli strongly reduced, poorly visible at high magnification; habitus as in Fig. 1; aedeagus as in Figs. 8– 9; Khamar-Daban mountain range................................................................................. L. dabanensis sp.n.