Cricotopus annulator

Author: Goetghebuer, 1927

Diagnosis (in part after Hirvenoja, 1973a - in italics)
Exuviae 3.0-5.5mm long (m=3.8mm, n=19).
Cephalothorax: Cephalic tubercles and frontal setae absent. Antennal sheath base weakly swollen. Thoracic horn 35-170µm long (m=120µm, n=19), apically pointed and at least apically with points; ThR 3.5-9.7 (m=7.4, n=18) (091r.jpg).
Abdomen: Length hook row II 0.36-0.44 of width tergite II (n=5); hooks 45-76 (m=58, n=16). Pedes spurii B well-developed on segment II, absent on III. Anterior and posterior point patches on tergites III-VI usually clearly separated, anterior band kidney-shaped. Point patches absent on tergites VII and VIII. Dorsal setae I-VIII: 4,4,4,5,5,5,5,2(1); Lateral setae I-VIII: 1,3,3,3,3,3,4,4(5); Ventral setae I-VIII: 1,3-4,4,4,4,4,4,0; lateral seta 4 on VIII somewhat stronger than the other lateral setae (091s.jpg), seta D2 almost in line with lateral setae on VIII.
Anal segment: Anal lobe ratio 1.3-1.8 (m=1.6, n=12). Fringe absent. Anal macrosetae more or less equally strong, length 0.55-0.97x length of the anal lobe (m=0.69, n=16).
(Linked adult male: Langton and Pinder, 2003a)

Note: The exuviae of Cricotopus albiforceps is very similar but the four lateral setae of segment VIII, all similar in size, the frontal setae on praefrons, and/or the obvious yellowish granular conical mound at the base of the antennal sheaths will separate it from annulator.

Species keys out at Page 948: Orthocladiinae 359 Cricotopus of the Text Key.

Holarctic species: widespread in Europe.
(For more information see module IdentifyIt – file: Orthocladiinae).

Ecological notes
Streams and northern lakes.