Hydrobaenus distylus

Author: (Kieffer, 1915)

Diagnosis (Material in coll. ZSM)
Exuviae 5.1-6.4mm long (n=5) (041-1.jpg).
Cephalothorax: Frontal setae on frontal apotome, 80-105µm long (n=4). Thoracic horn 365-508µm long, small-toothed, sharply pointed apically (041b.jpg); ThR 4.4-6.1 (n=6).
Abdomen: Tergites without a median transverse row of strong points. Apical bands present on tergites II-IV, that on II ( ‘ hook row II’) as broad as the tergite armament. Tergites III-V between the dorsal setae with more or less evenly distributed small points, which are gradually a little larger posteriorly on each segment. Three or four lateral setae on segments II-VI, not taeniate; lateral taeniae of segments VII and VIII: 4,4.
Anal segment: Anal lobe ratio 1.5-1.7 (n=3). Fringe of anal lobe with 23-36 short taeniae (n=5); longest 130-145µm, 0.3-0.4x length of the anal lobe (n=3). The three anal macrosetae rather strongly hooked, 0.71, 0.82x length of the anal lobes (n=2) (041c.jpg).

Species keys out at Page 640: Orthocladiinae 52 Hydrobaenus of the Text Key.

NW+C Europe (except British Isles).
(For more information see module IdentifyIt – file: Orthocladiinae).

Ecological notes
Stagnant and flowing water.