Tanytarsus pe4b

Form described by Langton, 1991
(Possibly the pupa of Tanytarsus excavatus Edwards.)

Diagnosis (n=1)
Exuviae 3.8mm long.
Cephalothorax: Cephalic tubercles absent. Frontal setae robust, 95µm long. Antennal sheath tubercle prominent, blunt conical. Thoracic horn 515µm long, horn without spinules; ThR 30.3. Posterior thoracic mound very weak. Wing sheaths rounded apically, pearl row absent.
Abdomen: Hooks of hook row II 86. Small rounded point patches present on tergite II anteriorly; III with points only; IV and V with the armament arranged in longitudinal bands. Armament tergite IV strong, 95µm long. ArR II-VI 0.37 : 0.74 : 1.0 : 0.89 : 0.79. Postero-lateral comb of segment VIII 45µm wide, set on a transverse cushion-like pad; with 8/9 marginal teeth. Lateral taeniae of segments IV-VIII: 0,1,3,4,2?, taeniae well-developed.
Anal segment: Anal lobe ratio 1.35. Fringe of anal lobe with 18/18 taeniae, forming a complete series.

Form keys out at Page 457: Tanytarsini 98 Tanytarsus of the Text Key.

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

Ecological notes
A Scottish lake.