Krenosmittia halvorseni

Author: (Cranston and Saether, 1986)

Diagnosis (Material in coll. ZSM; in part after Tuiskunen and Lindeberg, 1986a - in italics)
Exuviae 2.1-2.2mm (n=4).
Colour: Abdominal segments greyish brown, with pale caudal margins. Thorax paler than abdomen, wing sheaths with darker stripes.
Cephalothorax: Frontal setae long (180-200µm) and strong, arising from distinct cephalic tubercles. Postorbitals 2, weak and about 40-50µm. 2 Median antepronotals, stronger (95-110µm) and weaker (70-80µm). 2 Lateral antepronotals, very weak. 3 Dorsocentrals. Thoracic horn elongate, narrow, closely transversely wrinkled and with minute points for most of its length (056b.jpg). One precorneal seta strong (80-100µm), and 2 setae very weak.
Abdomen: Tergites (II)III-VIII with a posterior transverse row of teeth elevated on a ridge of cuticle, medially broken on tergites (II)III-VII, continuous on tergite VIII. Tergites IV-VI without a distinct circular antero-median point patch. Pedes spurii A and B absent. Abdominal segments with three conspicuous lateral setae, the fourth extremely weak or absent. Dorsal setae I-VIII: 5,5,5,5,5,5,5,5; Lateral setae I-VIII: 2-3,3-4,3-4,3-4,3-4,3-4,3-4,3; Ventral setae I-VIII: ?,4,4,4,4,4,4,1. 2 Anterior lateral setae long and strong, 3rdconsiderably weaker, an additional very weak and short seta often present. Seta D5 very strong and long in I-V.
Anal segment: Horns of segment IX very long (70-80µm), longer than the anal segment (056d.jpg). Anal lobes each with 3 very short (25-30µm) anal macrosetae, fringe absent.

Species keys out at Page 735: Orthocladiinae 147 Krenosmittia of the Text Key.

Holarctic species: Fennoscandia.
(For more information see module IdentifyIt – file: Orthocladiinae).

Ecological notes
Northern streams and lakes.