Strenzke, 1959
Body
Living larvae are red. Four ventral tubules on the 11th abdominal segment of equal length and normally coiled Chir. tubules coiled. Segment 10 without tubules. Procercus and anal tubules present (Wiederholm, 1983; Vallenduuk and Moller Pillot, 2002).
Head
Width 500 - 700 µm, the frontal apotome is pale and the gula is intermediate (Vallenduuk and Moller Pillot, 2002).
Antenna
The antenna consists of 5 segments, the first segment 102 - 131 µm long (Vallenduuk and Moller Pillot, 2002). The blade is not longer than the flagellum. Lauterborn organs distally on the second segment.
Mentum
The mentum has three median teeth and 6 pairs of lateral teeth with mentum type 1 Mentum type 1 pict. Ventromental plates with 46 - 50 hooks.
Labrum
SI is plumose and labral lamellae are normal.
Mandible
The mandible with a pale dorsal tooth, apical tooth dark and 3 inner teeth of type 3 Chiron mand lll9. The pecten mandibularis is present and seta interna with 4 toothed and plumose branches.
Differential characteristics
Chironomus is the only genus with 2 pairs of tubules on the 11th segment Chir 4 ventral tubules. Some species lack the ventral tubules (C. salinarius Chir no tubules, C. nudiventris and C. agilis). C. salinarius occurs only in brackish and salt water. The latter two species have a pair of lateral setae on segment 10 Chir 2 lateral tubules. These two species can be separated from Einfeldia pagana by the absence of a pit on the frontal apotome.
C. piger can be separated from all other Chironomus (except C. riparius) by:
Two pairs of coiled ventral tubules on segment 11 and no tubules on segment 10.
Gula intermediate and inmost mandible tooth as dark as the others (type 3). C. piger can be separated from C. riparius by the ventromental plates with 46 - 50 outer hooks (C. piger 35 - 45 hooks).