Orthocladius holsatus

Author: Goetghebuer, 1937

Diagnosis (data from Dettinger-Klemm, 2001a included)
Exuviae 3.8-4.4mm long (n=5) (079-1.jpg).
Cephalothorax: Thoracic horn elongate, 265-345µm long (n=5), armed with points (079b.jpg); ThR 9.8-13.3 (n=5). Four dorsocentral setae, the first, third and fourth thick, the second conspicuously thinner.
Abdomen: Hook row II a discrete pad or band of hooks, less than 0.34x width of segment II, usually of three or more transverse rows of hooks. Tergites III-V with median point patch transverse, separate from the posterior band, of narrow, sharp points, differing markedly from the short, sturdy points of the posterior band (079c.jpg). Posterior transverse point band on tergite III not extending further laterally than the apical band. No granulation present on tergites and sternites. Forked or branched setae rare and usually confined to the apical sternites. Pedes spurii B on segment II conspicuous. Conjunctives blotched with brown. Posterior lateral seta of segments VII and VIII thick and set upon a small tubercle.
Anal segment: Anal lobe ratio 1.8 (n=1). Anal lobes without fringe. Length of anal macrosetae/length of anal lobe 0.47-0.55 (male, n=4) and 0.55 (female, n=1), setae straight or somewhat curved. Genital sheaths of male about 342µm long, clearly surpassing apex of anal lobe (079d.jpg).
(Linked adult male: Langton and Pinder, 2003a)

Species keys out at Page 875: Orthocladiinae 286 Orthocladius of the Text Key.

N+W+C Europe.
(For more information see module IdentifyIt – file: Orthocladiinae).

Ecological notes
Stagnant and flowing water.