Cricotopus triannulatus

Author: (Macquart, 1826)

Diagnosis (in part after Hirvenoja, 1973a - in italics)
Exuviae 2.9, 3.9, 4.1mm long (n=3).
Cephalothorax: Cephalic tubercles absent; frontal setae usually on frontal apotome, only rarely on praefrons, 60, 105µm long (n=2). Thoracic horn 110, 135µm long; ThR 5.5, 8.4 (n=2) (091e.jpg).
Abdomen: Length hook row II 0.41, 0.47 of width tergite II (n=2); hooks 48-71 (n=3). Pedes spurii B weak on II and even weaker on III. Strong point patches on tergites III-VI, the kidney-shaped anterior patches separated from the posterior patches. Point patches absent on tergites VII and VIII. Five lateral setae on segment VIII; fourth lateral seta of segment VIII no larger than setae 1-3 and 5 (091f.jpg). Dorsal setae I-VIII: 4,4,4,5,5,5,5,1(2); Lateral setae I-VIII; 1,3,3,3,3,3,3-4,5(4); Ventral setae I-VIII: 1,3,3,3,4,4,4,0-1; lateral seta 4 not noticeably stonger than the other lateral setae on VIII; dorsal seta 1 on segment VIII almost in line with the lateral setae (apparently 5 lateral setae).
Anal segment: Anal lobe ratio 1.4 (n=1). Anal lobes without fringe. Anal macrosetae more or less equally strong. Length of anal macrosetae 0.72, 0.79 length of the anal lobe (n=2).
(Linked adult male: Langton and Pinder, 2003a)

Species keys out at Page 954: Orthocladiinae 365 Cricotopus of the Text Key.

Holarctic species: widespread in Europe, north Africa, Canary Islands.
(For more information see module IdentifyIt – file: Orthocladiinae).

Ecological notes
Streams, rivers and montane lakes.