Tanytarsus aculeatus

Author: Brundin, 1949

Exuviae 4.8-5.9mm long (m=5.3mm, n=14).
Cephalothorax: Cephalic tubercles small, conical; frontal setae 43-60µm long (n=5). Antennal sheaths without a basal swelling. Thoracic horn 600-814µm long (m=698µm, n=10); ThR 8.0-16.0 (m=10.9, n=10). Thoracic horn setulated along one side over the middle half, setulae 50-63µm long (n=5), usually as long as the horn is broad (141m.jpg). Posterior thoracic mound weak. Wing sheaths rounded apically, pearl row absent.
Abdomen: Length hook row II 0.29, 0.31x width tergite (n=2); hooks 64-107 (m=86, n=7). Tergites III-VI with the antero-median patches paired, arranged in longitudinal bands. Point patches of tergite III of points only, patches longitudinally elongate, narrow, tapering posteriorly and greater than one quarter the length of the segment (141n.jpg). ArR III-VI 1.17-2.03 : 1.0 : 0.69-0.90 : 0.34-0.81 (m=1.41 : 1.0 : 0.77 : 0.63, n=14). Armament tergite IV strong, 105-325µm long (m=153µm, n=11). Comb of segment VIII 45-60µm wide (n=11); with 6-10 marginal teeth (n=10). Lateral taeniae of segments V-VIII: 1(0),1,2,4, the taeniae broad.
Anal segment: Anal lobe ratio 1.06-1.33 (n=4). Fringe of anal lobe with 19-30 taeniae (m=24.8, n=14), forming a complete series.
(Linked adult male: Langton and Pinder, 2003a)

Note: The abdominal point bands are very variable in length, but usually much shorter than in Tanytarsus gracilentus and Tanytarsus sinuatus, about one third segment length; it also differs from them in not having a conical projection on the antennal sheath base.

Species keys out at Page 467: Tanytarsini 108 Tanytarsus of the Text Key.

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

Ecological notes
Pools and lakes.