Male:
Total length 9.80 (8.40-13.47) mm. Wing length 4.15 (3.79-4.32) mm. Wing length/length profemur 4.48 (3.99-6.09).
Colouration: Head brown to pale brown, wings hyaline and without markings; apical tip truncated; VR 1.07 (1.02-1.11); 4 (3-5) Scf on brachiolum; 18 (13-29) setae on squamal fringe.
Head: Antenna with 11 segments but antennal plume reduced; AR 1.54 (1.27-1.70).
Temporal setae: 3-8 inner verticals; 6-14 outer verticals and 7-16 postorbitals. Clypeus with 16 (5-22) setae. F/T 114 x139 µm (i.e. 12% wider than long). Palp segments (means) 92 : 75 : 235 : 141 : 131; P5/P4 0.55-0.97, P5/P3 0.56-0.57.
Thorax with well developed tubercle. Antepronotum with no setae.
Thoracic setae: acrostichals 6, short & decumbent; Dorsocentrals 15 (10-19); prealars 9 (7-11); scultellars 10 (6-15).
Legs: Mid and hind legs reduced in length. Spur of hind tibia reduced or missing on some specimens. No beard on anterior tarsi.
Lengths (in µm) and proportions of legs of Chironomus gelhausi male (n = 15).
|
Fe
|
Ti
|
Ta1
|
Ta2
|
Ta3
|
Ta4
|
Ta5
|
LR
|
BV
|
BR
|
Fore
|
880-920
|
880-940
|
1280-1320
|
680-720
|
560-600
|
480-520
|
200-240
|
1.40-1.45
|
1.53-1.58
|
1.78-1.81
|
Mid
|
1000-1140
|
840-880
|
480-540
|
280-320
|
160-200
|
120-160
|
100-120
|
0.57-0.61
|
3.20-3.52
|
2.14-2.23
|
Hind
|
1160-1200
|
1040-1080
|
720-760
|
360-380
|
280-300
|
120-160
|
120-140
|
0.69-0.70
|
3.10-3.17
|
2.20-2.46
|
TIX covered with microtrichia, with no median setae anterior of the anal point and 50 (39-61) setae on each side of the base of the anal point; anal tergite bands forming a shallow "U" and not reaching the base of the anal point. Anal point broad, parallel sided and rapidly constricting to a small point. Transverse stemapodeme nearly straight.
The hypopygium is rotated up to 180° in all specimens examined.
Female
Total length 8.79 (8.53-9.24) mm. Wing length 5.11 (5.02- 5.24) mm. Wing length/length profemur 4.63 (4.32-5.07). Coloration as in male.
AR 0.57 (0.51-0.67). Flagellomere length (µm): 245 : 127 ; 117 ; 133 ; 353 : A5/A1 1.44. FT 76 x 96 µm, i.e. length 79% of width. Clypeus with 28 (22-33) setae. Palpal segments (µm) 92 : 68 : 251 : 129 : 155: P5/P4 1.06-1.20; P5/P3 0.62-1.03.
Thorax with well developed tubercle, antepronotum with no setae. Setae: no apparent acrostichals; dorsocentrals 15 (13-19) (no indication as to whether any humerals); prealars 8 (7-9); Scutellar 11 (7-16) uniserial.
Wing with apical tip truncated as in male; VR 1.10 (1.08-1.11). 4(3-4) Scf on brachiolum; 16 (14-17 setae on squama.
Legs: Mid and hind legs reduced in length.
Lengths (in µm) and proportions of legs of Chironomus gelhausi female (n = 3).
|
Fe
|
Ti
|
Ta1
|
Ta2
|
Ta3
|
Ta4
|
Ta5
|
LR
|
BV
|
BR
|
Fore
|
1821
|
1817
|
1766-1839
|
973
|
728-771
|
609-648
|
322-336
|
0.97-1.01
|
1.93-2.01
|
0.81-0.99
|
Mid
|
1958
|
2017
|
738-768
|
479
|
404-405
|
313
|
230
|
0.35-0.38
|
3.31-3.32
|
0.61-0.99
|
Hind
|
2165
|
2260-2288
|
1276
|
853
|
671
|
471
|
266
|
0.56
|
2.47-2.53
|
0.75-0.76
|
The original data for this table seems confused so there is no guarantee that it is accurate
Abdomen: TVIII with 34 (32-37) setae; Sternite VIII with 149 (122-179).
Genitalia: Gonocoxite IX without setae; tergite IX with 53 (51-56) setae. Gonocoxapodeme rounded and not joined mesally. Cercus 393 (355-424) µm long. Gonopophyses VIII divided into a dorsomesal lobe and well-developed ventrolateral lobe: apodeme lobe weak, without microtrichia; Segment X expanded forming a collar around basal half of cerci.
Pupa and Larva unknown
Found: Type locality - Tunamal Nuur, Great Lakes region of MONGOLIA.
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