Chironomus improvidus

Author: Hirvenoja, 1962

Diagnosis (n=1, reared specimen coll. M. Hirvenoja)
Exuviae 9.5mm long.
Colour: Exuviae extensively brown.
Cephalothorax: Cephalic tubercles conical, LxB 150x100µm. Thoracic horn much branched.
Abdomen: Hook row II medially broken; hooks 40/33. Armament of tergites II-VI in the form of an undivided, usually extensive patch of strong points, the points in each segment increasing in size posteriorly. Posterior points of tergites III, IV and V conspicuously larger than those in mid-tergite. The point patches increase in extent from tergite II to V, but on VI the patch is more or less reduced. Armament of tergite II not spreading out laterally in front of the anterior adhesion marks. Armament of tergites more extensive: e.g. tergite IV with marmoration restricted to the lateral margin of the point patch, points usually reaching as far laterally as seta D2. Parasternites II-IV armed with points. Anterior points of sternite VII spiculate and grouped in irregular rows; those of the tergite more robust, resembling in shape the smaller points on the preceding tergite. Pedes spurii B of segment II conspicuous. Pleura IV unarmed. Conjunctives III/IV and IV/V with a small lateral seta, V/VI and VI/VII unarmed or very weakly armed. Comb of segment VIII with reticular ridging at base and 1 apical tooth + 1/2 subsidiary teeth. Lateral taeniae of segments V-VIII: 4,3/4,3/4,4.
Anal segment: Fringe of anal lobe with 73 taeniae.

Species keys out at Page 145: Chironomini 42 Chironomus of the Text Key.

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

Ecological notes