Tanytarsus medius

Author: Reiss and Fittkau, 1971

Exuviae 3.8-4.7mm long (m=4.4mm, n=10) (144-1.jpg).
Cephalothorax: Cephalic tubercles rounded. Frontal setae 70-85µm long (n=3). Antennal sheath bases with a broad conical tubercle. Thoracic horn 245-430µm long (m=338µm, n=11); ThR 12.6-25.3 (m=18.7, n=9). Thoracic horn with minute spinules from near base to tip, spinule 8µm long (n=3) (144b.jpg). Posterior thoracic mound very weak, inconspicuous. Wing sheaths rounded apically, pearl row absent.
Abdomen: Length hook row II 0.2, 0.21x width tergite; hooks 62-66 (n=3). Spine band of tergite III situated further back on the tergite and overlap setae D5; bands crescent-shaped, curved outwards so that if the line of the spine bases is extended posteriorly it cuts the lateral margin of the segment (144c.jpg). Tergites IV and V with the armament arranged in longitudinal bands. Armament tergite IV strong, 195-220µm long (n=8). ArR III-VI 0.61-0.82 : 1.0 : 0.28-0.34 : 0.14-0.25 (n=8). Postero-lateral comb of segment VIII 38-70µm wide; with 6-10 marginal teeth (n=9) (144d.jpg). Lateral taeniae of segments V-VIII: 0,0,2(0,1),5.
Anal segment: Anal lobe ratio 1.20-1.43 (n=4). Fringe of anal lobe with 31-41 taeniae (m=36, n=13), forming a complete series (144e.jpg).
(Linked adult male: Langton and Pinder, 2003a)

Note: This species is also smaller than Tanytarsus multipunctatus and has fewer hooks in the hook row of tergite II arranged in a single row (in multipunctatus about 100 hooks are arranged in approximately three imbricating rows).

Species keys out at Page 487: Tanytarsini 128 Tanytarsus of the Text Key.

Widespread in Europe, north Africa.
(For more information see module IdentifyIt – file: Chironominae).

Ecological notes
Lakes and ditches.