Vivacricotopus ablusus

Author: Schnell and Saether, 1988

Diagnosis (n=6, material in coll. ZMBN; in part after Schnell and Saether, 1988a - in italics)
Exuviae 3.5-4.0mm long (041-2.jpg).
Cephalothorax: Frontal setae moderately long, on frontal apotome; frontal apotome with weak to moderately developed warts, slightly wrinkled; antennal sheath at most with 2-4 pearls above pedicel; ocular field with 2 postorbitals. Thoracic horn 188-225µm long, cylindrical, tapering towards apex, covered with not very dense points; ThR 5.1-7.7 (041j.jpg). 2 median and 2 lateral antepronotal setae, all well developed; 2 anterior precorneal setae subequal in length and about 2x as long as posterior seta. Thorax slightly wrinkled, wing sheaths nearly smooth.
Abdomen: Tergite I bare. Tergites II-VII(VIII) with a posterior transverse band of strong points, strongest on VI and VII, otherwise with minute points only. Sternite I without shagreen; II-VIII with weak anterior group shagreen, more extensive on posterior sternites and grading over into weak caudal spines; caudal margin of sternites II-VII with 3-4 rows of similar, but weaker caudal spines, very weak or reduced to a few points on II. Pedes spurii A and B absent. Setae on tergites I-VIII: dorsal 1,5,5,5,5,5,5,1; lateral 1,4,4,4,4,4,4,5; ventral 2,4,4,4,4,4,4,1; Od 0,2,2,2,2,2,2,0. Posterior two lateral taeniae of segments VII and VIII conspicuously broad (about 15µm) and set on large, 12µm diameter sockets (041k.jpg).
Anal segment: Tergite IX with weak anterior and narrow median shagreen; sternite IX bare. Anal lobe ratio 1.9-2.1. Anal fringe with 7-13 short taeniae; longest 95-115µm long, 0.36-0.46x lobe length. Anal macrosetae very robust, thorn-like; length of setae 0.65-0.73x lobe length; 8-14µm wide (041k.jpg , 041l.jpg).

Species keys out at Page 647: Orthocladiinae 59 Vivacricotopus of the Text Key.

Northern Europe.
(For more information see module IdentifyIt – file: Orthocladiinae).

Ecological notes
A glacial river, Norway.