Chironomus aberratus

Author: Keyl, 1961

Diagnosis (Keyl reared specimens from type locality in coll. ZSM)
Exuviae 8.6-9.8mm long (n=4).
Colour: 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 conical, LxB 85x117-115x125µm (n=3). Frontal setae 50-57µm long (n=4). Thoracic horn much branched; basal ring of thoracic horn 157x73-175x83µm. Tracheal patch of horn without an "eye", patch 107x37-123x37µm; 10-12 tracheoles across (n=3); 2.5-3µm in diameter. Thorax small granulate anteriorly and dorsally as far as the anterior edge of the wing sheath.
Abdomen: Hook row II entire, length of row 0.5x width tergite (n=1); hooks 96-112 (n=4). Armament of tergites II-VI in the form of an undivided patch of strong points, the points in each segment increasing in size posteriorly. Armament of tergites rapidly diminishing in size anteriorly, e.g. on tergite III the points between the anterior adhesion marks very small, the patch appearing to evanesce anteriorly (102h.jpg). Sternite III, and often IV, with lateral longitudinal shagreen bands and an anterior transverse band. Parasternite II obviously shagreened; III without shagreen; IV may have a few minute points in posterior half. Conjunctives IV/V and V/VI at most minutely "rough" Pleura IV very sparsely spinulate or smooth. Comb of segment VIII with 3-6 elongate teeth (n=4) 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 91-124 taeniae (n=4).

Species keys out at Page 207: Chironomini 104 Chironomus of the Text Key.

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

Ecological notes
Cold humus-rich montane pools.