Orthocladius maius

Author: Goetghebuer, 1942

Diagnosis (Material in coll. ZSM)
Exuviae 5.0-6.5mm long (m=5.5mm, n=24).
Cephalothorax: Thoracic horn elongate, 395-490µm long (m=429µm, n=17), coarsely toothed; ThR 5.1-8.8 (m=6.4, n=15). 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. Median point patches of tergites III-V usually completely fused to the posterior band to form a single trapezoidal patch, points grading antero-laterally into shagreen (078g.jpg). Posterior transverse point band on tergite III not extending further laterally than the apical band. No granulation present on tergites and sternites. Pedes spurii B on segment II conspicuous. Conjunctives without brown blotches. Forked or branched setae rare and usually confined to the apical sternites.
Anal segment: Anal lobes rarely with apical teeth; when present, colourless and small. Anal lobe ratio 1.4-1.9 (m=1.6, n=12). Anal lobes without fringe. Anal macrosetae 0.61-0.88x length of the anal lobe (m=0.75, n=15).

Species keys out at Page 870: Orthocladiinae 281 Orthocladius of the Text Key.

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

Ecological notes
Lakes and streams.