Demicryptochironomus Lenz, 1941

Mukherjee, Bindarika & Hazra, Niladri, 2022, Two new species of Demicryptochironomus Lenz, 1941 from India with tentative phylogenetic relationship and a revised world key to known males (Diptera: Chironomidae), Zootaxa 5175 (1), pp. 88-100 : 95-96

A world key to the males of Demicryptochironomus Lenz

(Followed after Yan et al., 2008)

1. Anal tergite bands V- or U-shaped; superior volsella digitiform or bilobed, with or without microtrichia; minute inferior volsella present or absent; gonostylus banana–shaped, without median constriction (subgenus Demicryptochironomus )........... 2

- Anal tergite bands Y-shaped; superior volsella digitiform or racquet-shaped, never bilobed; inferior volsella absent; gonostylus constricted medially (subgenus Irmakia ).................................................................. 20

2. Inferior volsella present................................................................................ 3

- Inferior volsella absent................................................................................ 11

3. Gonostylus without conspicuous longitudinal keel; anal point strongly swollen medially (Orient).............................................................................................. D. minus Yan, Tang et Wang, 2005

- Gonostylus with distinct longitudinal keel; anal point falciform or nearly parallel-sided............................. 4

4. Inferior volsella bare (Palaearctic, Orient)............................ D. inawabeceus (Sasa, Kitami et Suzuki, 1999)

- Inferior volsella with setae and/or microtrichia.............................................................. 5

5. Inferior volsella sheet-shaped, without setae, and covered entirely with microtrichia................................ 6

- Inferior volsella tubercle-shaped or lobe-shaped, with setae, covered with microtrichia basally or without microtrichia..... 7

6. Gonostylus rounded apically; superior volsella thumb-like (Palaearctic, Orient).. D. asamaprimus Sasa et Hirabayashi, 1991

- Gonostylus pointed apically; superior volsella with 1–3 tubercles (Palaearctic, Orient)........... D. tamacutus (Sasa, 1983)

7. Inferior volsella without microtrichia...................................................................... 8

- Inferior volsella with microtrichia........................................................................ 9

8. Inferior volsella with 1–2 large, even tubercles, bearing 2 apical setae (Palaearctic, Orient)..... D. chuzequartus Sasa, 1984

- Inferior volsella widened at base, with small lateral projection, bearing 1 apical and 1 subapical seta (Palaearctic, Orient)............................................................................. D. harunasecundus (Sasa, 1996)

9. Gonostylus nearly straight; inferior volsella lobe-like, with microtrichia in basal 2/3 (Palaearctic, Orient)..................................................................................... D. ginzancedeus Sasa et Suzuki, 2001

- Gonostylus bent medially or in apical 1/3; inferior volsella tubercle-like, with microtrichia at base.................... 10

10. Anal point parallel-sided; superior and inferior volsella subequal in length, neither surpassing margin of gonostylus; HR 1.75– 1.80 (Palaearctic, Orient)............................................................. D. evgenii Zorina, 2004

- Anal point widened at apical 1/3, superior volsella 1.88–2.00 times longer than inferior volsella, both surpassing margin of gonostylus, HR 1.00 (Palaearctic, Orient)................................................ D. lutoga Zorina, 2004

11. Superior volsella with single long seta (Palaearctic, Orient).............................. D. uresicarinus Sasa, 1989

- Superior volsella with at least two long setae.............................................................. 12

12. Superior volsella club shaped (Orient)...................................................... D. praeacutus sp. n.

- Superior volsella variable shaped........................................................................ 13

13. Base of anal point with shoulders making it subrectangular (Afrotropical)................... D. zairensis Lehmann, 1979

- Base of anal point triangular............................................................................ 14

14. Gonostylus without or weekly developed longitudinal keel................................................... 15

- Gonostylus with strong longitudinal keel................................................................. 18

15. Superior volsella covered with microtrichia................................................................ 16

- Superior volsella without microtrichia.................................................................... 17

16. Superior volsella pediform (Palaearctic)........................................... D. paracamptolabis Ree, 2012

- Superior volsella two small tubercle like (Orient)............................ D. antennarius Yan, Tang et Wang, 2005

17. Anal point with median ridges covered with microtrichia (Orient)...................... D. yui Yan, Tang et Wang, 2005

- Anal point bare, without median ridges (Palaearctic, Orient)......................... D. irioabeus Sasa et Suzuki, 2000

18. Superior volsella patch-like; gonostylus nearly parallel-sided (Orient)............... D. pannus Yan, Tang et Wang, 2005

- Superior volsella digitiform; gonostylus curved............................................................ 19

19. Superior volsella bilobed apically; U shaped anal tergite band (Orient).................. D. vulneratus ( Zetterstedt, 1838)

- Superior volsella consisting of two finger like unequal lobe; anal tergite band absent (Palaearctic).................................................................................................... D. wontongensis Ree, 2012

20. Superior volsella without setae (Orient).................................... D. clarilatus ( Guha et Chaudhuri, 1981)

- Superior volsella with setae............................................................................ 21

21. Superior volsella partly divided apically (Orient)............................................... D. dividuus sp. n.

- Superior volsella variable shaped........................................................................ 22

22. Tergite IX with shoulder-like posterior margin............................................................. 23

- Tergite IX with cone-shaped posterior margin............................................................. 24

23. Superior volsella digitiform, with 2 apical setae; anal point nearly parallel-sided (Afrotropical)............................................................................................... D. cinereithorax Goetghebuer, 1934

- Superior volsella spatulate, with 3 subapical setae; anal point strongly constricted medially (Orient)...................................................................................... D. retusus Yan, Saether, Jin et Wang, 2008

24. AR 3.25; base of anal point large, about 2/3 as long as anal point (Holarctic)................ D. cuneatus ( Townes, 1945)

- AR 1.14–2.64; base of anal point small, less than 1/2 as long as anal point....................................... 25

25. Base of anal point not constricted; anal point parallel-sided or conical.......................................... 26

- Base of anal point constricted; anal point spatulate.......................................................... 29

26. Superior volsella swollen distally, with subapical setae....................................................... 27

- Superior volsella parallel-sided, with apical setae.......................................................... 28

27. AR 1.63; gonostylus with strong inner concavity in apical 1/3; superior volsella with 2 setae (Palaearctic, Orient).............................................................................. D. concavus Yan, Tang et Wang, 2005

- AR 2.27; gonostylus with weak inner concavity in apical 1/3, superior volsella with 3 setae (Palaearctic, Orient)......................................................................... D. oyabeprimus (Sasa, Kawai et Ueno, 1988)

28. Gonostylus with basal projection and rounded apex (Palaearctic, Orient).................... D. neglectus ( Reiss, 1988)

- Gonostylus without basal projection and pointed apex (Holarctic, Orient)................. D. fastigatus ( Townes, 1945)

29. Superior volsella narrow, digitiform, pointed, with 1 median lateral seta and 1 subapical seta (Orient)................................................................................................... D. banepae ( Reiss, 1988)

- Superior volsella cylindrical or swollen distally, with 2–3 subapical or apical setae................................ 30

30. Superior volsella cylindrical with 2 apical setae............................................................ 31

- Superior volsella racket-like, swollen at apex, with 2 subapical setae............................................ 32

31. Ridges on base of anal point with lateral setae; gonostylus strongly curved in apical 1/3; AR 2.32; LR 1 1.93 (Orient)........................................................................... D. constrictus Yan, Tang et Wang, 2005

- Ridges on base of anal point without lateral setae; gonostylus weakly curved in apical 1/3; AR 1.41–1.62; LR 1 1.60–1.69 (Palaearctic)....................................................................... D. schachti Reiss, 1988

32. Anal point strongly swollen medially, ridges with lateral setae; AR 2.03; LR 1 1.86–2.08 (Orient)............................................................................................... D. spatulatus Wang et Zheng, 1994

- Anal point slightly swollen medially, ridges without lateral setae; AR 1.43–1.56; LR 1 1.71–1.72 (Palaearctic)................................................................................................ D. latior Reiss, 1988