Tanytarsus mendax

Author: Kieffer, 1925

Exuviae 4.0-6.3mm long (m=5.0mm, n=39).
Cephalothorax: Cephalic tubercles elongate conical, 60-110µm high (n=6). Frontal setae 95-180µm long (n=10). Antennal sheath base with a conspicuous conical projection. Thoracic horn 550-1050µm long (m=802µm, n=20); ThR 10-33.2 (m=20.1, n=11). Middle section of thoracic horn with setae 50-85µm long (n=12), setae as long as or longer than the diameter of the horn (143g.jpg). Posterior thoracic mound moderate. Wing sheaths rounded apically, pearl row absent.
Abdomen: Length hook row II 0.3x width tergite (n=1); hooks 78-107 (n=5). Tergite II without an anterior pair of point patches; III with points only; IV and V with the armament arranged in longitudinal bands. Armament tergite IV strong, 75-175µm long (m=116µm, n=33). ArR III-VI 0.62-1.27 : 1.0 : 0.72-1.0 : 0.4-0.69 (n=33). Postero-lateral comb of segment VIII 34-86µm wide (m=58.3, n=29); with 6-17 marginal teeth (m=9.6, n=32). Lateral taeniae of segments V-VIII: 0,0/1,3/2(1,4),5.
Anal segment: Anal lobe ratio 0.91-1.1 (n=4). Fringe of anal lobe with 33-57 taeniae (m=43, n=52), forming a complete series.
(Linked adult male: Langton and Pinder, 2003a)

Note: Very similar to Tanytarsus occultus Brundin but easily distinguished when the antennal sheath projection is laterally compressed, but if vertically compressed there may be doubts as to identity; however, the tubercle of occultus is so small that it would be difficult to detect except laterally. The setulae of the thoracic horn are 50µm or more long, whereas in occultus they are shorter and fewer in number. Also very similar to Tanytarsus fimbriatus.

Species keys out at Page 474: Tanytarsini 115 Tanytarsus of the Text Key.

Holarctic species: widespread in Europe.
(For more information see module IdentifyIt – file: Chironominae).

Ecological notes
Standing water.