Polypedilum pedestre

Author: (Meigen, 1830)

Diagnosis
Exuviae 5.5-10.0mm long (m=8.3mm, n=7).
Cephalothorax: Cephalic tubercles indistinct humps with frontal setae, setae 60-110µm long (m=88µm, n=9). Thoracic horn of a few (about 10) branches, branches much shorter than half the length of the abdomen. Thorax with conspicuously large granules near suture (112b.jpg).
Note: The granulate anterior thorax is unusual amongst Polypedilum, best developed in large examples.
Abdomen: Length hook row II 0.50-0.61x width tergite (n=9); hooks 41-73 (m=60; n=10); without an additional patch of small points or hooks at each end. Tergites II-VI with obvious anterior transverse bands of points stronger than those of the median patch. Armament of tergites II-V continuous: an anterior transverse band of points joined broadly to the postero-median trapezoidal or rectangular marmorate patch of smaller points (122h.jpg). Tergites III and IV armed with an apical band of points or hooks. Tergite VII without trace of a median point patch. Sternite I without two antero-lateral armed humps. Pedes spurii B II well-developed. Conjunctives with points no larger than those of the anterior transverse bands of the tergites. Vortex present. Comb of segment VIII a brown or golden-brown spur ending in a strong tooth with up to 3 small teeth externally and/or internally towards base (122i.jpg). Lateral taeniae of segments IV-VIII: 0,3,3,4,4, taeniae well-developed.
Anal segment: Fringe of anal lobe dense, with 49-108 taeniae (m=81, n=110) extending only to the tip of the lobe externally; lobes without a dorsal seta.
(Linked adult male: Langton and Pinder, 2003a)

Species keys out at Page 322: Chironomini 219 Polypedilum of the Text Key.

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

Ecological notes
Streams.

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