Polypedilum sordens

Author: (van der Wulp, 1874)

Exuviae 5.4-6.6mm (m=5.9mm long, n=22) (121-2.jpg).
Cephalothorax: Cephalic tubercles in the form of shallow humps; frontal setae 25-38µm long (n=6). Thoracic horn of a few (about 10) branches. Thorax with conspicuously large granules near suture (112b.jpg).
Abdomen: Length hook row II 0.46-0.60x width tergite (m=0.54, n=8); hooks number more than 55 (m=68, n=16). Tergites II-VI with obvious anterior transverse bands of points stronger than those of the median patch with which they may be confluent for the tergite width. Only segment IV with apical band of points, set well back on the tergite, with a point-free space in front (121e.jpg). Armament of tergite VII medially interrupted. Sternite I without two antero-lateral armed humps. Pedes spurii B II well-developed. Vortex present. Segment IV without lateral taeniae. Segment V with no more than three lateral taeniae.
Anal segment: Fringe of anal lobe with 43-64 taeniae (m=50, n=32) (121f.jpg).
(Linked adult male: Langton and Pinder, 2003a)

Species keys out at Page 307: Chironomini 204 Polypedilum of the Text Key.

Holarctic species: widespread in Europe.
(For more information see module IdentifyIt – file: Chironominae).

Ecological notes
Northern and montane lakes; southern ponds and slow flowing drains and rivers.