Cladotanytarsus atridorsum

Author: Kieffer, 1924

Exuviae 3.1-3.9mm long (m=3.4mm, n=11) (136-1.jpg); usually very transparent, sometimes a little infuscated.
Cephalothorax: Cephalic tubercles elongate conical, 43-77µm high (n=6) (136c.jpg). Thoracic horn 230-325µm long (n=5), tapered to rounded apex, margined along one edge with setae 129µm long (n=2), length 0.40, 0.47x length of horn (n=2) (136b.jpg); ThR 12.0, 16.2 (n=2). Pearl row absent.
Abdomen: Tergites II-VI each with an anterior pair of point patches; ArR II-VI 07-0.9 : 1.0-1.1 : 1.0 : 1.0-1.1 : 0.7-0.9 (n=7). Armament tergite IV strong (136d.jpg), 50-60µm long (n=8). Comb on postero-lateral corner of segment VIII 50-86µm wide (m=64.5µm, n=10); with 4-10 marginal teeth (m=6.3, n=10). Lateral taeniae of segments IV-VIII: 0(3),0(1,3),3(4),4,5.
Anal segment: Fringe of anal lobe with 28-44 taeniae (m=32.3, n=10) (136e.jpg).
(Linked adult male: Langton and Pinder, 2003a)

Note: Cladotanytarsus wexionensis Brundin, according to Brundin, 1949a is very similar; Shilova, 1976a distinguishes wexionensis as having more robust cephalic tubercles, only as high as they are broad at base, rugulose in basal half, whereas those of atridorsum are described as being narrower and smooth. However, the shape of atridorsum cephalic tubercles depends on how the exuviae are mounted and the cuticle at their base can be weakly rugulose.

Species keys out at Page 415: Tanytarsini 57 Cladotanytarsus of the Text Key.

Holarctic species: widespread in Europe, Canary Islands.
(For more information see module IdentifyIt – file: Chironominae).

Ecological notes
Lakes and reservoirs.