Tanytarsus buchonius

Author: Reiss and Fittkau, 1971

Exuviae 3.3-4.9mm long (n=7).
Cephalothorax: Cephalic tubercles short conical. Frontal setae 50, 75µm long (n=2). Antennal sheath base with a truncate or pointed granular swelling. Thoracic horn 525-685µm long, without long setulae; ThR 16.1-27.4 (n=5). Posterior thoracic mound moderately swollen. Wing sheaths rounded apically, pearl row absent.
Abdomen: Length hook row II 0.32, 0.46x width tergite (n=2); hooks 83-108 (n=3). Armament of tergite II of smaller points, a pair of longitudinal bands joined anteriorly and often posteriorly; narrowest medially, leaving a broad median bare space. Tergite III possessing spine bands of tergite III without an external border of points, any lateral points restricted to the anterior half of the spine band. Tergites IV and V with the armament arranged in longitudinal bands. Armament tergite IV strong, 125-225µm long (n=8). ArR III-VI 1.03-1.48 : 1.0 : 0.65-0.77 : 0.33-0.62 (n=8). Maximum spine length III 78-100µm long; IV 25-63µm long (n=4), on IV spines restricted the posterior half of the longitudinal bands, or, rarely, composed of points only (139i.jpg). Postero-lateral comb of segment VIII 50-55µm wide (n=3); with 6-10 marginal teeth (n=6). Lateral taeniae of segments V-VIII: 1(2),3(2),4(3),4.
Anal segment: Anal lobe ratio 1.25-1.4 (n=5). Fringe of anal lobe with 18-34 taeniae (m=28, n=10), forming a complete series beginning near the anterior edge of the lobes.
(Linked adult male: Langton and Pinder, 2003a)

Note: Some specimens of Tanytarsus pallidicornis are very similar to buchonius; but in pallidicornis on each side of the smooth mid-line of tergite II the points gradually decrease in size posteriorly, the anterior points conspicuously larger than the posterior, often bifid at apex and arranged irregularly, whereas in buchonius the anterior points are mostly no larger than the posterior and are arranged in short transverse rows of 2-5 points, most obvious where the anterior points spread out laterally in front of setae D1.

Species keys out at Page 452: Tanytarsini 93 Tanytarsus of the Text Key.

NW Europe and Italy.
(For more information see module IdentifyIt – file: Chironominae).

Ecological notes
Peat pools and boggy seepages.