Diamesa permacra

Author: (Walker, 1856)

Exuviae 6.3-9.3mm long (n=3).
Cephalothorax: Frontal setae 370, 380µm long (n=2). Thoracic horn 550-630µm long; ThR 26.4-27.5 (n=3). Precorneal setae 2,3: 343, 450; 220, 275µm long (n=2). (030e.jpg)
Abdomen: Hook row II absent. Total dorsal teeth II-VIII 66, 92 (n=2). Total ventral teeth III-VII/VIII 66, 88 (n=2) (030f.jpg). Relative length segments IX:VIII:VII = 1.0:0.71,0.76:0.98,1.1 (n=2); relative width segments IX:VIII:VII = 1.0:1.2,1.34:1.4,1.8 (n=2). Segment VIII 2.3, 2.4 and segment VII 2.0, 2.1 times as wide as long (n=2). Lateral setae 1-4 of segment III 212, 215; 225, 240; -- 187, 215; 100, 120µm long (n=2).
Note: Buff to pale gold, the abdominal tergites a little darker than the paratergites; the brown anterior transverse apodemes narrowly margined in front with golden brown; the tooth row set on a pale golden band; all adhesion marks brownish; tips of dorsal and ventral teeth dark brown.
Anal segment: Anal lobe ratio 1.4-1.6 (n=3). Each anal lobe with 3 macrosetae; length macrosetae 0.7, 0.78 times lobe length (n=2).
(Linked adult male: Langton and Pinder, 2003a)

Species keys out at Page 553: Diamesinae 29 Diamesa of the Text Key.

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

Ecological notes
Cool montane streams below 1,000m asl.