Form described by Langton, 1991
Diagnosis
Exuviae 4.2-4.8mm long (n=9).
Cephalothorax: Cephalic tubercles shallow broad mounds. Frontal setae 30-40µm long (n=3; usually absent). Thoracic horn of a few (about 10) branches, branches much shorter than half the length of the abdomen. Thorax with conspicuously large granules near suture (112b.jpg).
Abdomen: Length hook row II 0.35-0.51x width tergite (n=3); hooks 44-61 (n=7). 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. Tergite VII has a reduced point patch, armament medially interrupted. Tergites III and IV armed with an apical band of points or hooks (122l.jpg). Sternite I without two antero-lateral armed humps. Pedes spurii B II absent. Conjunctives with points no larger than those of the anterior transverse bands of the tergites. Vortex present. Comb of segment VIII of one or two strong teeth and some smaller points grouped on the apico-lateral corner of the segment. Lateral setae of anterior segments minute; of segments V and VI about three times their length but still setaceous; only segments VII and VIII have flattened taeniae; lateral taeniae of segments V-VIII: 0,0(1),4(3),4(3).
Anal segment: Each anal lobe with 15-22 fringe taeniae (n=7) and at most 1 dorsal seta.
Form keys out at Page 312: Chironomini 209 Polypedilum of the Text Key.
Distribution
(For more information see module IdentifyIt – file: Chironominae).
Ecological notes
Northern lakes.