Lenz, 1921
Body
Medium sized to large larvae up to 12 mm long. Claws on the posterior parapods are simpel. No lateral and ventral tubules (Wiederholm, 1983; Moller Pillot, 1984a).
Head
Antenna
The antenna consists of 5 segments. The basal segment is longer than the flagellum. Lauterborn organs distally on the second segment or absent.
Mentum
The mentum has 1 Parach arc mentum or 2 median teeth and 7 pairs of lateral teeth Parach vitiosus mentum. The ventromental plates 0.9-1.2x as wide as the mentum.
Labrum
SI is simpel or divided into 3-5 teeth (P. longiforceps group) and labral lamellae are absent. The pecten epipharyngis is a plate with about 7 distal teeth Parach arc pecten epiph. The premandible has 2-4 apical teeth Parach vitiosus premandible.
Mandible
The mandible with a small dorsal tooth or absent, one long apical tooth and 2 inner teeth triangular or flattened Parach vitiosus mandible 8. The pecten mandibularis is absent and seta interna is also absent in some species.
Differential characteristics
The species with one median mental tooth can be distinguished by the flat mentum and 7 pairs of lateral teeth. Parach arc mentum. The species with 2 median teeth can be separated by the 7 pairs of lateral teeth, flat mentum Parach vitiosus mentum and 2-4 teeth on the premandible Parach vitiosus premandible where Harnischia has 6 teeth.
Diversity
European species: 17
Treated taxa:
Species-group Parachironomus gr. arcuatus
Parachironomus biannulatus
Parachironomus frequens