Key to the known species of Pagastia Oliver of Holarctic region

Males

1. Eyes hairy. Aedeagal lobes reduced (subgenus Hesperodiamesa Sublette). Basal lobe of gonocoxite small.................................................................... P. (H.) sequax (Garrett, 1925) (Makarchenko 2019, Fig. 18)

– Eyes bare or pubescent. One or two aedeagal lobes present (subgenus Pagastia Oliver). Basal lobe of gonocoxite large.... 2

2. Both median and lateral aedeagal lobes present. AR 2.5-4.2................................................... 3

– Only lateral aedeagal lobe present. AR 1.0–2.42............................................................ 6

3. Antepronotum with dorsal and lateral setae in widely separated groups. Median aedeagal lobe digitated and widest distally. 4

– Antepronotum completely covered with setae. Median aedeagal lobe widest medially, then tapering abruptly and with the apex forming a sharp hook.......................... P. (Pagastia) partica (Roback, 1957) (Makarchenko 2019, Figs.16–17)

4. Gonostylus subapically with “heel”................ P. (P.) nivis (Tokunaga, 1936) (Makarchenko 2006, Fig. 180, 5–10)

– Gonostylus subapically without “heel”.................................................................... 5

5. Apex of the gonostylus angled................. P. (P.) orientalis (Tshernovskij, 1949) (Makarchenko 2006, Fig. 181, 1–5)

– Apex of the gonostylus broadly rounded................................................................................................ P. (P.) altaica Makarchenko, Kerkis et Ivanchenko, 1997 (Makarchenko et al. 1997, Fig. 1)

6. Anal point absent. Alula as well as M 1+2, M 3+4, and Cu 1 of wing with setae................................................................................ .. P. (P.) subletteorum Makarchenko (Makarchenko 2019, Figs. 1–6, 19–20)

– Anal point present. Alula and M 1+2, M 3+4, Cu 1 without setae.................................................... 7

7. Anal point almost parallel-sided in dorsal view; lateral aedeagal lobe tapering to thin apex........................... 8

– Anal point tapering to apex; lateral aedeagal lobe broad in distal part........................................... 10

8. Anal point with rounded apex and without apical peg.. P. (P.) orthogonia Oliver, 1959 (Makarchenko 2019, Figs. 7 –13, 21)

– Anal point with pointed apical peg........................................................................ 9

9. Gonostylus with small basal lobe in outer side; apically rounded, without “heel”. AR 1.56–1.75............................................................................. P. (P.) hidakamontana Endo, 2004 (Endo 2004, Figs. 1–6)

– Gonostylus with rounded basal lobe in outer side and with lobe like “heel” apically. AR 1.22–1.26........................................................................................ P. (P.) donoliveri sp. nov. (Figs. 4, 6, 7, 9)

10. Anal point narrow, tapering to pointed apex, without apical peg; gonostylus in basal part with outer angle-shaped projection. AR 2.18–2.42................. P. (P.) tianmumontana Makarchenko et Wang, 2017 (Makarchenko &Wang 2017, Fig. 17)

– Anal point widest in basal part and thin apically, pointed and sometimes with apical peg; gonostylus without outer basal projection and with rounded apex. AR 1.81–2.10........ P. (P.) lanceolata (Tokunaga, 1936) (Makarchenko 2006, Fig. 180, 1–4)