(Holmgren, 1869)
Subgenus Pogonocladius Brundin, 1956
Body
Medium sized larvae up to 9 mm long. The L4 setae are simpel and > 150 µm. The anterior and posterior parapods are separate and bear rows of claws. Procercus and two pairs of anal tubules present (Wiederholm, 1983; Moller Pillot, 1984b).
Head
Head length 0.55 - 0.70 mm. Eye composed of three separated eyes, one large and two small ones in front Pogo cons head (Moller Pillot, 1984b)
Antenna
The antenna consists of only four segments Pogo cons antenna. The blade is shorter than the flagellum. Lauterborn organs are conspicuous (Moller Pillot, 1984b).
Mentum
The mentum has one median tooth and 6 pairs of lateral teeth. The median tooth not as high as the first laterals and second laterals somewhat reduced, Pogo cons mentum. The ventromental plates are weak. The beard is present (Wiederholm, 1983).
Labrum
The pecten epipharyngis consists of three scales, SI is bifid and the premandible has one or two apical teeth (Wiederholm, 1983; Moller Pillot, 1984b).
Mandible
The mandible has an apical tooth and 3 inner teeth.
Differential characteristics
Orthocladius can be separated from all other genera, except Paratrichocladius, by the bifid SI, mentum with 1 median tooth and 6-9 pairs of lateral teeth, 5 segmented antenna (4 in O. consobrinus) and simpel body seta. Paratrichocladius however has a blueish thorax in freshly preserved larvae and a lobed ring beneath the ssd of the mandible. Both characters are absent in Orthocladius.
O. consobrinus can be separated from all other Orthocladius by the compound eye in three parts Pogo cons head and the 4 segmented antenna Pogo cons antenna.