Chironomus holomelas

Author: Keyl, 1961

Diagnosis (n=3, Strenzke identified specimens in coll. ZSM)
Exuviae 8.5-9.8mm long.
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 50x63-87x100µm; apical third narrow, nearly cylindrical, apex LxB 30x20-63x45µm. Frontal setae 30-43µm long. Thoracic horn much branched; basal ring 107x55-133x65µm; tracheal patch 75x23-110x30µm; 10-13 tracheoles across; 2µm in diameter. Tracheal patch of thoracic horn without an "eye". Thoracic granulation weak, best developed anteriorly and by suture.
Abdomen: Hook row II entire, length of row 0.52-0.53x width tergite; hooks 94-122. Armament of tergites II-VI in the form of an undivided, extensive patch of strong points, e.g. on tergite III extending to embrace the lateral of the anterior adhesion marks and to seta D3 posteriorly (102g.jpg). Armament of tergites II-VI not strongly waisted and with the posterior transverse band not successively increasing in extent to tergite VI; usually reduced on VI; the points in each segment increasing in size posteriorly. Parasternite II obviously shagreened; III without shagreen; IV may have a few minute points in posterior half. Pleura of segment IV spinulate, spinules 10µm long. Comb of segment VIII with 1-4 stout 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; each lobe with 72-107 fringe taeniae.

Species keys out at Page 180: Chironomini 77 Chironomus of the Text Key.

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

Ecological notes
Montane and northern pools and ditches.