Pagastia Oliver, 1959

Makarchenko, Eugenyi A., Semenchenko, Alexander A. & Palatov, Dmitry M., 2021, New species and findings of Pagastia Oliver (Diptera: Chironomidae: Diamesinae) from Central Asia, with DNA barcoding of known species of the genus, Zootaxa 4951 (3), pp. 559-570 : 561

Key to the known species of Pagastia Oliver

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.............................................................. 3

- Only lateral aedeagal lobe present........................................................................ 8

3. Antepronotum with dorsal and lateral setae in widely separated groups. Median aedeagal lobe digitated, widest in distal part or wedge-shaped and widest at base......................................................................... 5

- Antepronotum completely covered with setae. Median aedeagal lobe widest medially, with apex forming a sharp hook or wedge-shaped, with fingerlike apex....................................................................... 4

4. 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)

- Median aedeagal lobe wedge-shaped, with finger-like apex............................ P. (P.) hanseni sp. nov. ( Fig. 7 )

5. Median aedeagal lobe digitated, widest in distal part......................................................... 6

- Median aedeagal lobe wedge-shaped, with toothed apex...................... P. (P.) caelestomontana sp. nov. ( Fig. 2 )

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

- Gonostylus subapical without “heel”..................................................................... 7

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

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

8. 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.................................................... 9

9. Anal point almost parallel-sided in dorsal view; lateral aedeagal lobe tapering to thin apex.......................... 10

- Anal point tapering to apex; lateral aedeagal lobe broad in distal part........................................... 12

10. 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....................................................................... 11

11. Gonostylus with small basal lobe in outer side; apical part 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” in apical part. AR 1.22–1.26......................................... P. (P.) donoliveri Makarchenko et Hansen, 2020 ( Makarchenko & Hansen 2020, Figs. 4, 6–7 , 9 )

12. 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 projec- tion and with rounded apex. AR 1.81–2.10........ P. (P.) lanceolata (Tokunaga, 1936) ( Makarchenko 2006, Fig. 180, 1–4)

Figures

FIGURE 16. Bayesian tree based on mitochondrial COI and COII genes for available members of the genus Pagastia Oliver with Pseudodiamesa stackelbergi (Goetghebuer) as outgroup. Bayesian posterior probabilities (PP) are given above tree nodes and bootstrap support values found in the ML analysis are shown below nodes.

FIGURES 1–7. Pagastia (P.) caelestomontana sp. nov. (1–4) and P. (P.) hanseni sp. nov. (5–7), males. 1, 6, anteropronotum in dorsal view; 2, 7, aedeagal lobes; 3, 5, hypopygium in dorsal view; 4, anal point. Bl, basal lobe of gonocoxite; LAl, lateral aedeagal lobe; MAl, median aedeagal lobe TSa, transverse sternapodeme. Scale bars for figures 1, 3, 5, 6 – 200 µm, for figures 2, 4, 7 – 50 µm.

FIGURES 8–11. Pagastia (P.) caelestomontana sp. nov. (8–9) and P. (P.) hanseni sp. nov. (10–11), males. 8, 10, hypopygium in dorsal view; 9, gonostylus; 11, anal point.