Orthocladius obumbratus

Author: Johannsen, 1905

Exuviae 4.6-5.7mm long (n=8) (078-1.jpg).
Colour: Brownish with darker anterior and lateral margins to the tergites.
Cephalothorax: Thoracic horn 420-480µm long (m=453µm, n=10), coarsely toothed (078b.jpg); ThR 4.1-7.2 (m=5.8, n=7). 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. Points of the median patches on tergites III-V obviously demarcated from the antero-lateral shagreen where there is a sudden drop in point size. Median point patches of tergites III-V usually completely fused to the posterior band to form a single trapezoidal patch, the points of median and posterior bands of about the same size and form. 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 lobe ratio 1.4-1.7 (n=6). Anal lobes without fringe. Anal lobes may be weakly fringed with hair-like teeth in addition to the apical teeth, apical teeth usually brown, sturdy and often fused at base, occasionally colourless, but always present. Length of anal macrosetae 0.64-0.77x length of the anal lobe (n=5).
(Linked adult male: Langton and Pinder, 2003a)

Species keys out at Page 872: Orthocladiinae 283 Orthocladius of the Text Key.

Holarctic species: widespread in Europe.
(For more information see module IdentifyIt – file: Orthocladiinae).

Ecological notes
Streams and northern lakes.