Parachironomus arcuatus

Author: (Goetghebuer, 1919)

Exuviae 4.6-6.4mm long (m=5.3mm, n=32).
Cephalothorax: Cephalic tubercles conical, 50-130µm high (n=7); length 1.1-2.4x breadth (n=6) (110i.jpg). Thoracic horn much branched. Thoracic granulation fine, without conspicuously larger granules near suture. Posterior thoracic mound strongly swollen anteriorly and with a long posterior projection, which is often curved apically (110j.jpg).
Abdomen: Tergite armament of Parachironomus-pattern. Length hook row II 0.20-0.36x width tergite (m=0.30, n=13). Sternite I without toothed humps. Sternite II with both posterior and anterior transverse spine bands represented, though one or both of them may be interrupted medially. Vortex present. Comb of segment VIII of 0-7 small colourless spines in the apico-lateral corner near the bases of the fourth and fifth lateral taeniae (m=3.5, n=60). Lateral setae of anterior segments narrow, hair-like; lateral taeniae of segments V-VIII: 4(3,2),4(3),4,5.
Anal segment: Fringe of anal lobe with 42-121 taeniae (m=74, n=60).
(Linked adult male: Langton and Pinder, 2003a)

Species keys out at Page 249: Chironomini 146 Parachironomus of the Text Key.

Palaearctic species: widespread in Europe.
(For more information see module IdentifyIt – file: Chironominae).

Ecological notes
Lakes, ponds, ditches, slow flowing drains and rivers; occasionally in the outflow streams of lakes.