Diamesa latitarsis

Author: (Goetghebuer, 1921)

Exuviae 3.8-5.7mm long (m=4.6mm, n=8) (030-1.jpg).
Cephalothorax: Frontal setae 125µm long (n=2). Thoracic horn 125-257µm long (m=208µm, n=6); ThR 10-17.5 (m=15.5, n=6). Precorneal setae 2,3: 90, 150; 85, 140µm long (n=2). (030b.jpg)
Abdomen: Tergites II-IV behind posterior tooth rows with a band of small points, and the posterior tooth row of segment I well-developed; total dorsal teeth I-VIII 97-118 (n=8). Total ventral teeth III/IV-VII/VIII 51-78 (n=8). (030c.jpg) Shagreen points on tergites strong and extensive, spreading behind the posterior median adhesion marks; points of tergite III 5-7.5µm long (030-1.jpg). Lateral margins of segments II-V strongly serrate. Relative length segments IX:VIII:VII = 1.0:0.48-0.56:0.75-0.84 (n=3); relative width segments IX:VIII:VII = 1.0:1.23-1.26:1.47-1.6 (n=3). Segment VIII 2.5-3.2 and segment VII 2.25-3.0 times as wide as long (n=3). Lateral setae 1-4 of segment III 50, 75; 50; -- 58, 67; 63-70µm long (n=3).
Note: Tan to very pale golden brown, the tergites faintly outlined anteriorly and laterally with pale brown; teeth (largest 30µm long) golden-brown to brown, set on golden or golden-brown mounds joined by a similarly coloured transverse stripe; lateral margins of the segment tinged with gold.
Anal segment: Anal lobe ratio 1.35-1.8 (m=1.6, n=8). Each anal lobe with 3 macrosetae; length macrosetae 0.6-0.7x lobe length (n=3). (030d.jpg)
(Linked adult male: Langton and Pinder, 2003a)

Species keys out at Page 561: Diamesinae 37 Diamesa of the Text Key.

Widespread in Europe and NW Africa.
(For more information see module IdentifyIt – file: Other subfamilies).

Ecological notes
Montane streams and rivulets.