Eukiefferiella ilkleyensis

Author: (Edwards, 1929)

Exuviae 2.0-3.3mm long (m=2.6mm, n=18).
Cephalothorax: Thoracic horn 95-165µm long (m=131µm, n=12); base 65-135µm long, in distal half with obvious short spinules; apical filament 0.62-0.84x length base (m=0.74, n=7) (051d.jpg); ThR (base) 1.1-1.7 (m=1.4, n=12). Median antepronotal setae 1,2: 105-150; 100-115µm long (n=4); precorneal setae 1-3: 135-185; 130-143; 75-100µm long (n=3); dorsocentral setae 1-4: 68-90; 30-50; 70-90; 10-20µm long (n=4). Pearl row absent.
Note: Specimens that have lost the thoracic horn may not be distinguishable from Eukiefferiella devonica (Edwards), but ilkleyensis only very rarely loses its thoracic horns and has the median antepronotal setae more similar in length.
Abdomen: Hook rows on tergites continuous; hooks III 12-29, IV 13-27, V 13-25 (n=18). Posterior teeth of tergites III-V long, 2-3x or more the length of the bases of the hooks of the hook rows, dense; teeth III 23-30µm; IV 23-30µm long (n=4). Sternite VII without a posterior transverse row of hooks. Segment VIII with one long, thick lateral seta and another that is finer and shorter.
Anal segment: Anal lobe ratio 1.2-1.5 (m=1.3, n=9). Anal lobes without fringe. Length of anal macrosetae 0.72-0.82x length of the anal lobe (n=2). Inner macroseta of anal lobes weaker than the other two.
(Linked adult male: Langton and Pinder, 2003a)

Species keys out at Page 722: Orthocladiinae 134 Eukiefferiella of the Text Key.

Holarctic species: widespread in Europe (not Scandinavia), circum-Mediterranean.
(For more information see module IdentifyIt – file: Orthocladiinae).

Ecological notes
Streams, middle reaches to source.