Thienemanniella acuticornis

Author: (Kieffer, 1912)

Exuviae 1.9-2.0mm long (n=5) (035-2.jpg).
Cephalothorax: Thoracic horn and pearl row absent.
Abdomen: Posterior points on tergites II-IX much enlarged and set on tubercles, sometimes resembling the armament of Metriocnemus spp.. Tergites III-VI with an apical transverse row of small hooks, absent from tergite II (035-1.jpg). Only 1 lateral taenia on each of the segments III-VI, usually 1 on VII and only 3 on VIII.
Anal segment: Anal lobe ratio 1.5-1.7 (n=3). Fringe of anal lobe with 9-16 taeniae (m=12, n=8); taeniae restricted to the posterior half, with a row of small teeth ventrally, internal to the insertion of the taeniae (035e.jpg). Apical setae of anal lobes cylindrical, hooked apically.
(Linked adult male: Langton and Pinder, 2003a)

Species keys out at Page 595: Orthocladiinae 7 Thienemanniella of the Text Key.

Palaearctic species: widespread in Europe (not Scandinavia), circum-Mediterranean.
(For more information see module IdentifyIt – file: Orthocladiinae).

Ecological notes
Montane streams; larvae in damp moss.