Chironomus riihimakiensis

Author: Wülker, 1973

Diagnosis (Locus typicus material from M. Hirvenoja.)
Exuviae 9.1-11.4mm long (n=8).
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 conical, LxB 95x90-120x120µm (n=6). Frontal setae 56-80µm long (n=5). Basal ring of thoracic horn 185x90-215x105µm; tracheal patch 135x40-160x48µm (n=6); 14-19 tracheoles across 3.3-3.4µm in diameter. Tracheolar patch of thoracic horn without an "eye". Anterior thorax densely granulate, the granules about one granule diameter apart.
Abdomen: Hook row II entire, length of row 0.45-0.50x width tergite (n=3); hooks 89-99 (n=3). Tergite armament strong, particularly posteriorly on tergites IV and V, the most posterior points projecting, tooth-like over the conjunctive. 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. Parasternite II obviously shagreened. Pleura of segment IV spinulate. Conjunctives IV/V and V/VI more strongly armed with dense spine-like points. Comb of segment VIII with 1-4 (n=8), set on the end of an elongate ventral cuticular mound which exceeds appreciably the apico-lateral corner of the segment. Segment VIII with 5 lateral taeniae.
Anal segment: Anal lobe with 96-123 fringe taeniae (n=6).

Species keys out at Page 205: Chironomini 102 Chironomus of the Text Key.

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

Ecological notes