Diamesa incallida

Author: (Walker, 1856)

Diagnosis (n=2, unless stated otherwise, material in coll. ZMBN).
Exuviae 6.6, 7.9mm long.
Cephalothorax: Frontal setae 175, 185µm long. Thoracic horn 555µm long; ThR 22, 32.6. Precorneal setae 2,3: 135, 195; 125, 140µm long.
Abdomen: Hook row II absent. Total dorsal teeth II-VIII 66, 77. Total ventral teeth III-VII 69, 158. Dorsal and ventral teeth similar in shape, size (100µm long) and colour. Shagreen points on III 2.5µm long. Relative length segments IX:VIII:VII = 1.0:0.78:1.0 (n=1); relative width segments IX:VIII:VII = 1.0:1.3:1.5 (n=1). Lateral setae 1-3 of segments II-VII more or less equidistant, stout almost thorn-like, sometimes forked or branched. Lateral setae 1-4 of segment III 238; 225; 240; 105µm long (n=1) (032e.jpg).
Note: Tan; abdominal tergites margined anteriorly and narrowly along the lateral adhesion marks in brown; apices of teeth brown, bases and a broad connecting band golden.
Anal segment: Anal lobe ratio 1.2, 1.3. Each anal lobe with 3 dark macrosetae; length macrosetae 0.68, 0.74 times lobe length.
(Linked adult male: Langton and Pinder, 2003a)

Species keys out at Page 572: Diamesinae 48 Diamesa of the Text Key.

Holarctic species: Widespread in (northwest) Europe.
(For more information see module IdentifyIt – file: Other subfamilies).

Ecological notes
Cold montane streams.