Orthocladius frigidus

Author: (Zetterstedt, 1838)

Exuviae 5.1-7.5mm long (m=6.0mm, n=22) (075-1.jpg).
Cephalothorax: Thoracic horn 855-1155µm long (m=935µm, n=9), smooth and narrow, brown at base, colourless thereafter (075b.jpg); ThR 19.4-25.7 (m=22.2, n=9). 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. Pedes spurii B II present.
Anal segment: Anal lobes rounded externally and tapered from the middle to the apical setae (075d.jpg). Anal lobe ratio 1.5-1.7 (n=13). Anal lobes without fringe. Length of anal macrosetae 0.48-0.62x length of the anal lobe (n=13).
Colour: Brown exuviae with transparent conjunctival bands.
(Linked adult male: Langton and Pinder, 2003a)

Species keys out at Page 857: Orthocladiinae 268 Orthocladius of the Text Key.

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

Ecological notes
Montane streams and lakes; larvae on stones at the water surface.