Author: Willassen, 1985
Diagnosis (n=3, unless stated otherwise, material in coll. ZMBN)
Exuviae 3.6-5.2mm long.
Cephalothorax: Frontal setae 135-160µm long. Thoracic horn 158-335µm long; ThR 5.3-19.7. Precorneal setae 1-3: 35-140; 100-110; 60µm long. Thorax granulate.
Abdomen: Hook row II absent. Rarely less than 7 teeth in tooth row of tergite II; tergites VI and VII each with over 10 teeth. Total dorsal teeth II-VIII 68-122. Total ventral teeth III-VIII 41, 49 (n=2). Behind the tooth rows there is a band of points; points of tergites III-VII spreading posteriorly outside the anterior adhesion marks, extending the point patch towards the postero-lateral corner, progressively more extensive on succeeding segments (031d.jpg). Shagreen points on III 6µm long. Lateral setae 1-3 of segments II-VII short; setae 1 of segment III 50-65µm long.
Anal segment: Anal lobe ratio 1.3 (n=1). Each anal lobe with 4 lateral macrosetae; length macrosetae 0.6-0.7x lobe length (n=2).
Species keys out at Page 575: Diamesinae 51 Diamesa of the Text Key.
Distribution
Fennoscandia.
(For more information see module IdentifyIt – file: Other subfamilies).
Ecological notes
Glacier brooks and cold streams in the north.