Polypedilum aegyptium

Author: Kieffer, 1925

Exuviae 3.1-4.7mm long (m=3.8mm, n=8).
Cephalothorax: Cephalic tubercles rounded or rounded-conical (125m.jpg). Frontal setae 63-75µm long (n=5). Thoracic horn of about 8 broad filaments, filaments much shorter than half the length of the abdomen. Thorax with conspicuously large granules near suture (112b.jpg).
Abdomen: Length hook row II 0.5-0.56x width tergite (n=4); hooks 43-66 (m=60, n=8); 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 (124a.jpg). Tergites III and IV armed with an apical band of points; points of the apical bands much smaller than those of the median point patches. 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 of separate golden-yellow teeth OR a weak brownish spur with blunt teeth (124c.jpg). Segment IV without lateral taeniae; V-VIII with well-developed lateral taeniae, no more than three lateral taeniae on V.
Anal segment: Fringe of anal lobe with 17-31 taeniae (n=8) in a single row extending only to the tip of the lobe externally; lobe with a dorsal seta.
(Linked adult male: Langton and Pinder, 2003a)

Note: This form is variable in two main respects which can make the exuviae look rather different; the median points of tergites II and III may be as large or nearly as large as those of the anterior band, or the anterior band possesses distinctly larger points than the median patch; these latter specimens have the comb of segment VIII more spur-like with only small points on the lateral margin of the segment, not resembling the usual Tripodura condition, but the presence of the dorsal seta on the anal lobe will reassure. It is possible that more than one species is represented, though both extremes have very similar adult male hypopygia.

Species keys out at Page 325: Chironomini 222 Polypedilum of the Text Key.

Afrotropical species; widespread in Europe, circum-Mediterranean.
(For more information see module IdentifyIt – file: Chironominae).

Ecological notes
Streams and rivers; lakes in the north.