Chironomus dorsalis

Chironomus (s. str.) dorsalis sensu Strenzke nec Meigen, 1818

Diagnosis (Identified from material reared by Strenzke in coll. ZSM. Also karyotypically confirmed material by J. Martin and P. Michailova)
Exuviae 7.5-8.1mm long (n=4).
Colour: Exuviae golden-brown to dark brown. Contrast in colour between thorax and abdomen not so strongly marked: specimens dark anteriorly also have the abdomen infuscated; outer margin of the anal lobes coloured except at base.
Cephalothorax: Cephalic tubercles LxB 90x80µm (n=2). Frontal setae 50µm long (n=1). Thoracic horn much branched; basal ring 107x45-120x55µm; tracheal patch 80x23-87x23µm; 9-12 tracheoles across (n=4). Tracheal patch of thoracic horn without an "eye". Thorax densely small granulate to the level of the anterior edge of the wing sheath; granulation strong anteriorly, elsewhere reduced.
Abdomen: Hook row II entire, length of row 0.51, 0.55x width tergite (n=2); hooks 44-59 (n=4). Armament of tergites II-VI in the form of an undivided patch of strong points, not strongly waisted and e.g. on tergite III extending laterally at most only as far as the inner edge of the lateral of the anterior adhesion marks and setae D4. The points in each segment increasing in size posteriorly; the posterior transverse band not successively increasing in extent to tergite VI; usually reduced on VI. Shagreen of sternite II with a definite gap posteriorly between the lateral longitudinal bands and the median patch. Sternites III and IV without shagreen. Parasternite II obviously shagreened; III without shagreen; IV may have a few minute points in posterior half. Pleura of segment IV apparently smooth, or with a very few scattered spinules. Conjunctives IV/V and V/VI at most minutely "rough". Comb of segment VIII with 2-5 somewhat elongate teeth, set on the end of an elongate ventral cuticular mound which exceeds appreciably the apico-lateral corner of the segment. Lateral taeniae of segments V-VIII: 4,4,4,5.
Anal segment: Anal lobes weakly rounded. Fringe of anal lobe with 82-116 taeniae (n=4).

Species keys out at Page 168: Chironomini 65 Chironomus of the Text Key.

Widespread in Europe, Middle East.
(For more information see module IdentifyIt – file: Chironominae).

Ecological notes
Ponds and shallow pools.