Chironomus pe34

new form

Diagnosis (n=1)
Exuviae 9.3mm 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 conical, LxB 200x160µm. Frontal setae 57µm long. Basal ring of thoracic horn 160x70µm; tracheal patch 124x30µm; 12 tracheoles across; 2.5µm in diameter. Tracheolar patch of thoracic horn without an "eye". Thorax less distinctly granulate: anteriorly the granules are small and distinct; medially most of the granules are somewhat flattened, producing an irregular reticulate pattern, or evanescent.
Abdomen: Hook row II entire, length of row 0.63x width tergite; hooks 123. Armament of tergites reduced, 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. 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. Sternite III with lateral shagreen bands restricted to the anterior half and spreading inwards anteriorly, but not meeting medially; the shagreen is composed of very small spinules arranged for the most part in long transverse rows. Sternite IV with lateral bands much reduced. Parasternite II obviously shagreened. Pleura of segment IV spinulate. Comb of segment VIII with 4 stout apiculate teeth, set on the end of an elongate ventral cuticular mound which exceeds appreciably the apico-lateral corner of the segment. Lateral taeniae on segments V-VIII: 4,4,4,5.
Anal segment: Anal lobe with 115 fringe taeniae.

Form keys out at Page 199: Chironomini 96 Chironomus of the Text Key.

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

Ecological notes
Lac de la Morlotte, Voges.