Chironomus heteropilicornis

Author: Wülker, 1996

Diagnosis (n=1, material in coll. Wülker)
Exuviae large, about 13mm long.
Cephalothorax: Cephalic tubercles LxB 155x125µm. Frontal setae 105µm long. Thoracic horn much branched; basal ring of horn 250x110µm; tracheal patch 185x65µm; 22 tracheoles across, 3µm diameter. Tracheal patch of thoracic horn with a distinct "eye": a tracheole-free hole running through the anterior lobe of the patch (102k.jpg). Thorax densely small granulate to posterior extent.
Abdomen: Hook row II entire, length of row 0.51x width tergite; 107 hooks. Armament of tergites II-VI in the form of an undivided, usually extensive patch of strong points, the points in each segment increasing in size posteriorly. Armament of tergites II-VI not so strongly waisted and with the posterior transverse band not successively increasing in extent to tergite VI; usually reduced on VI. The point patches increase in extent from tergite II to V, but on VI the patch is more or less reduced. Sternites III and IV with shagreen patches. Pleura IV spinulate. Comb of segment VIII dark brown, closely pleated longitudinally, with 2/3 short apical teeth, set on the end of an elongate ventral cuticular mound which exceeds appreciably the apico-lateral corner of the segment.
Anal segment: Anal lobes straight laterally, nearly parallel-sided (102j.jpg). Fringe of anal lobe with about 125 taeniae, well-spaced out anteriorly, very crowded posteriorly.

Species keys out at Page 153: Chironomini 50 Chironomus of the Text Key.

NE Europe.
(For more information see module IdentifyIt – file: Chironominae).

Ecological notes
Kyrksöjärvi, Finnland; shallow stagnant water.