Hydrosmittia

Zhang, Ruilei, Liu, Wenbin, Ferrington, Leonard C. & Wang, Xinhua, 2016, Two new species of genus Hydrosmittia Ferrington & Saether (Diptera: Chironomidae) from China, Zootaxa 4121 (2), pp. 167-174 : 172-173

Key to known male imagines of Hydrosmittia

(modified from Ferrington & Saether, 2011)

1. Phallapodeme with well sclerotized hook-like apical projection ending in 2–3 distinct, sharp teeth; virga apparently without lateral groups of spinules; superior volsella barely indicated; Japan........... H. togadistalis (Sasa, Watanabe & Arakawa)

- Phallapodeme without hook-like apical projection or if present very weekly sclerotized; virga consisting of median single spine, sometimes difficult to distinguish, and two rows of lateral spinules, superior volsella absent or indicated as basal swell- ing of inner margin of gonocoxite........................................................................ 2

2. Costa not extended................................................................................... 3

- Costa extended, often with additional false vein............................................................. 4

3. AR about 0.35, R4+5 ending proximal to apex of M3+4, lateral spinules of virga fused and sclerotized; Canada................................................................................................... H. setaven a (Saether)

- AR about 0.15, R4+5 ending distal to apex of M3+4, lateral spinules of virga not strongly sclerotized; Palaearctic............................................................................................... H. brevicornis Strenzke

4. Anal point parallel-sided for most of its length, about 46 µm long; Norway............... H. aagaardi Ferrington& Saether

- Anal point triangular, 0–43 µm long...................................................................... 5

5. Transverse sternapodeme without oral projections, inner verticals present........................................ 6

– Transverse sternapodeme with oral projections, inner verticals present or absent................................... 8

6. Gonostylus tapering to narrow apex; Tanzania.................................... H. tenuistylata Ferrington& Saether

– Gonostylus not tapering............................................................................... 7

7. Tergite I–III and most of VI and VII pale; Tanzania.................................. H. annulata Ferrington& Saether

– No pale tergites; Tanzania......................................................... H. soelii Ferrington& Saether

8. Inner verticals (1–2) conspicuous; accessory lobe of inferior volsella adpressed to gonocoxite; gonostylus with more or less well developed outer heel...............................................................................9

- Inner verticals absent, or if occasionally present as in some specimens of H. ruttneri short and inconspicuous; accessory lobe of inferior volsella well developed, usually free at apex; gonostylus without distinct outer heel;...................... 10

9. Virga consisting of a weak triangular median plate and lateral spinules; Holarctic and Oriental China. H. oxoniana (Edwards)

- Virga consisting of a sclerotized mace-like structure bearing 9 thorn-like spinules and a ventral median spine; Oriental China........................................................................................ H. spinata sp. n.

10. False vein continuing from R4+5, conspicuous, making the costal extension indistinguishable in most specimens, LR1 0.46– 0.54............................................................................................... 12

- False vein indistinct.................................................................................. 11

11. AR 2.02, wing length 2.3 mm; Japan........................................... H. kisotriangulata (Sasa& Kondo)

- AR 0.18–1.37, wing length 1.2–2.7 mm LR1 0.38–0.45; Holarctic................... H. ruttneri (Strenzke et Thienemann

12. AR 0.91–1.11, total length 3.16–4.17, wing length 2.13–2.67mm, virga consisting of a weak median plate with 18–30 lateral spinules; Kenya........................................................... H. falsicostata Ferrington& Saether

- AR 0.18–0.20, total length 1.98–2.43, wing length 1.10–1.43, virga consisting of a weak triangular median plate and 9 thorn- like spinules; Oriental China............................................................ H. continalinea sp. n.