Tanytarsus gibbosiceps

Author: Kieffer, 1922

Exuviae 4.2-5.5mm long (m=4.9mm, n=17).
Cephalothorax: Cephalic tubercles short conical. Frontal setae 103-135µm long (m=113µm, n=8). Antennal sheath base with a conical projection. Thoracic horn without long setulae. Thoracic horn 475-650µm long (m=591µm, n=6); ThR 12.5-18.6 (m=15.6, n=6). Posterior thoracic mounds swollen. Wing sheaths rounded apically, pearl row absent.
Abdomen: Length hook row II 0.34, 0.42x width tergite (n=2); hooks 83-131 (n=4). Armament of tergite II of smaller points, a pair of longitudinal bands joined anteriorly and often posteriorly; narrowest medially, leaving a broad median bare space. Spine bands of tergite III without an external border of points, any lateral points restricted to the anterior half of the spine band. The spine bands of tergite IV exceed three-quarters the length of those on III, composed of densely packed long spines (140h.jpg); longest spine III 110-140µm long (m=118µm, n=7); IV 75-98µm long (m=75µm). Armament tergite IV strong, 183-233µm long (m=206µm, n=7). ArR III-VI 1.27-1.07 : 1.0 : 0.61-0.38 : 0.50-0.31 (m=1.13 : 1.0 : 0.58 : 0.41, n=7). Postero-lateral comb of segment VIII 70-88µm wide; with 12-15 marginal teeth (n=6). Lateral taeniae of segments V-VIII: 3,3,4,4.
Anal segment: Anal lobe ratio 1.23-1.43 (n=5). Fringe of anal lobe with 32-47 taeniae (m=39, n=10), forming a complete series beginning near the anterior edge of the lobes.
(Linked adult male: Langton and Pinder, 2003a)

Note: Very like Tanytarsus bathophilus in general appearance, but the 3 lateral taeniae on segments V and VI will distinguish gibbosiceps from specimens of bathophilus in which the lateral setation of segment VIII is not clear.

Species keys out at Page 451: Tanytarsini 92 Tanytarsus of the Text Key.

C Europe, Great Britain.
(For more information see module IdentifyIt – file: Chironominae).

Ecological notes
Standing water.