Psectrocladius zetterstedti

Author: Brundin, 1949

Diagnosis (Material in coll. ZSM)
Exuviae 4.7-5.0mm long (n=6).
Colour: Anterior thorax distinctly brown, contrasting conspicuously with the nearly colourless abdominal segments; anal lobes more or less darkened apically.
Cephalothorax: Frontal setae present. Thoracic horn 338-388µm long (n=6), small-toothed; ThR 5.2-6.7 (n=5). Longest precorneal seta relatively shorter than in Psectrocladius sordidellus (Zetterstedt), e.g. for exuviae 4.7mm long, with about 38 fringe taeniae, 120µm long.
Abdomen: Tergites III-VIII with restricted shagreen, at least on VII and VIII. Median point patches on tergites IV-VI; point patches single, at least on tergites IV and V obviously so; occasionally constricted medially on VI. Points of point patches large, the longest greater than 35µm long, usually obviously exceeding the length of the longest tooth of the posterior transverse rows. Three or four lateral setae on segments II-V, not taeniate; lateral taeniae of segment VI (3)4. At least one lateral seta on segment VII, and all those on segment VIII taeniate.
Anal segment: Anal lobe ratio 1.7-1.8 (n=4). Anal lobes rounded apically, without teeth. Fringe of anal lobe with 32-40 taeniae (n=6); three anal macrosetae situated apically on the anal lobes.

Note: Hardly separable from Psectrocladius sordidellus structurally and the above distinctions may not hold, except that, of the great many P. sordidellus and Psectrocladius ventricosus specimens seen, none shows the strongly darkened anterior thorax of these specimens. However, these specimens may be extreme for zetterstedti and less coloured individuals may occur.

Species keys out at Page 679: Orthocladiinae 91 Psectrocladius of the Text Key.

Holarctic species: NW+C Europe.
(For more information see module IdentifyIt – file: Orthocladiinae).

Ecological notes