Author: (Zetterstedt, 1838)
Diagnosis
Exuviae 3.9-5.2mm long (m=4.6mm, n=12).
Cephalothorax: Cephalic tubercles rounded humps, weak, about 20µm high. Frontal setae 88-175µm long (m=122.4µm, n=10). Thoracic horn 8-branched, branches much shorter than half the length of the abdomen. Precorneal setae short and thin, the longer 30-40µm long (n=10). Thorax with conspicuously large granules near suture (112b.jpg).
Abdomen: Length hook row II 0.56-0.60x width tergite (n=3); hooks 51-71 (n=5). Tergites II-VI with obvious anterior transverse bands of points stronger than those of the median patch. Tergites with the median patches reduced, highly marmorate. Armament of tergites II-V or III-V discontinuous: at least the anterior transverse point band separate from the postero-median patch, which is narrowed anteriorly to a median point. Posterior transverse band of points deep (except medially, where it is interrupted or only narrowly joined posteriorly), spreading forwards beyond seta D5 as far as its extent behind (125f.jpg). Hooked points of apical bands of tergites III and IV about the same size as the points of the median patches of those tergites. Tergite VII without trace of a median point patch. Sternite I without two antero-lateral armed humps. Pedes spurii B of segment II usually present. Conjunctives with points no larger than those of the anterior transverse bands of the tergites. Vortex present. Comb of segment VIII composed of more widely separated teeth spreading laterally forwards from the apico-lateral corner (125g.jpg). Lateral taeniae of segments IV-VIII: 0,3,3,4,4, taeniae well-developed.
Anal segment: Anal lobes with a dorsal seta set towards the inner edge of the lobe; each lobe with 26-33 fringe taeniae (m=28, n=19).
(Linked adult male: Langton and Pinder, 2003a)
Species keys out at Page 332: Chironomini 229 Polypedilum of the Text Key.
Distribution
Palaearctic species: widespread in Europe, north Africa.
(For more information see module IdentifyIt – file: Chironominae).
Ecological notes
Northern and montane lakes; a shallow, fast flowing river in southern England.