Propsilocerus lacustris

Author: Kieffer, 1923

Diagnosis (Material in coll. ZSM; in part after Saether and Wang, 1996a - in italics)
Exuviae 9.0mm long (n=1); 4.73-9.64mm long (m=7.33mm, n=11-13).
Cephalothorax: Frontal setae on praefrons 100µm long (n=1); 36-98µm long (m=72µm, n=7). Thoracic horn 770µm long, small-toothed, bifid at apex or irregularly jagged apically (037b.jpg); ThR 4.3 (n=1). Thoracic horn flattened, distinctly bifid, with few apical spines; 482-775µm long (m=659µm); 95-180µm wide (m=130µm); 3.50-6.83x (m=4.97) as long as wide; 1.82-2.16x (m=1.97) as long as macrosetae. Precorneal setae 1,2: 120, 130; 55, 95µm long (n=2). Median antepronotal setae 1,2: 80-143; 143µm long (n=2); lateral antepronotal setae 1,2: 85; 125, 135µm long (n=2). Dorsocentral setae 1-4: 150; 170; 145; 125µm long (n=1). Anterior 2 precorneal setae moved forward to close to median antepronotals, posterior precorneal in the middle between horn and anterior precorneals. Precorneals, median and lateral antepronotals, postorbitals and dorsocentrals very variable in length, mostly taeniate, about 60-169µm long. Distance between dorsocentral setae 1 and 2: 26-131µm (m=92µm, n=4), between setae 2 and 3: 68-196µm (m=130µm, n=5), between setae 3 and 4: 41-64µm (m=49µm, n=5). Wing sheath not with strongly sclerotized margin.
Abdomen: Tergite I with a few median points; posterior margins of III-IV and laterally on V with anterior directed points. Tergites without a median transverse row of strong points. 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. Sternite II-VI with median points. Pedes spurii A present on sternites IV-VI, weak on sternites V-VI. Lateral setae segments I-VIII: 2-3,3,3,3,3-4,3-4,3-4,4; setae taeniate on VI-VIII. Fourth lateral seta of segments III and IV thick and over 100µm long. Lateral setae 1-4 of segment IV: 58, 65; 75, 98; 60, 65; 125, 150µm long (n=2).
Anal segment: Anal lobe ratio 1.6 (n=1). Anal macrosetae 6, 7 (n=2). Fringe of anal lobe with 45-49 taeniae (n=2); longest 170µm, 0.26x length of the anal lobe (n=1) (037d.jpg). Anal lobe 567-898µm (m=758µm) long; with 5-7 (m=7) macrosetae; 265-397µm (m=333µm) long; macrosetae 0.38-0.49x (m=0.44) as long as anal lobe; 28-48 (m=36) taeniae in fringe. Male genital sheaths overreaching by 0-94µm (m=41µm).

Species keys out at Page 635: Orthocladiinae 47 Propsilocerus of the Text Key.

Palaearctic species: Germany.
(For more information see module IdentifyIt – file: Orthocladiinae).

Ecological notes
Stagnant water.