Kieffer, 1919
Body
Large larvae up to 18 mm long. Living larvae are pale or red. The slender body tapers from the head to the anal segments. The thoracic segments are strongly thickened. No lateral and ventral tubules present. Posterior parapods are very short. The procercus is absent and anal tubules are large and point backwards (Wiederholm, 1983; Moller Pillot, 1984a).
Head
The headcapsule is flattened dorsoventrally and the frontoclypeal apotome is fused with the labrum so the labral sclerites 1 and 2 are absent.
Antenna
The antenna consists of 5 segments. The blade is broad and very small, only about as long as the second segment. Lauterborn organs very small on segment 2.
Mentum
The mentum is concave with 2 median teeth and 5 pairs of lateral teeth. The outer 2 pairs are fused to the large 3d lateral teeth Stenochir mentum 2. The ventromental plates are reduced to a tiny band of short striae beneath the outer lateral teeth.
Labrum
SI is distally plumose and labral lamellae are 2 small scales with distal spines. The pecten epipharyngis is replaced by 10-20 slender lamellae. The premandible has three teeth.
Mandible
The mandible is broad triangular without a dorsal tooth, apical tooth and 2 inner teeth present Stenochir mandible. The pecten mandibularis and seta interna are absent.
Differential characteristics
The body shape gradually narrowing towards the anal segment is distinctive. Also the combination of a concave mentum with 3-5 lateral teeth Stenochir mentum 2 and a 5 segmented antenna separate Stenochironomus from all other genera.
Diversity
European species: 2
Treated species: 0