Goetghebuer, 1937
Subgenus Orthocladius van der Wulp, 1874
Body
Medium sized larvae up to 7 mm long. The anterior parapods are separate. The two posterior parapods bear rows of claws. Procercus is present. Two pairs of anal tubules present. On the abdominal segments 1 - 7 the L4 the bundle large with up to 25 setae as long as the segment (Moller Pillot, 1984b ).
Head
The head is yellow.
Antenna
The antenna has a normal length and consists of five segments Cric ornatus antenna.
Mentum
The mentum has one median tooth and 6 pairs of lateral teeth. All lateral teeth are normally developed. Cric holsatus mentum.
Labrum
The pecten epipharyngis consists of three scales. SI is bifid. The premandible with 2 apical teeth (Hirvenoja, 1973).
Mandible
The mandible with a smooth inner side and the apical tooth is longer than the joined inner teeth. Cric holsatus mand
Differential characteristics
O. holsatus larvae resemble members of the genus Cricotopus by the setal tufts of the L4 Cric (C) 14 Cric (I) sylv body seta. O. holsatus can be separated from all Cricotopus s.s. by the mentum with middle tooth > 2.5 x the first lateral tooth, no reduced lateral teeth, the large L4 bundles and mandible with elongated apical tooth.
O. holsatus is easely separated from the other Orthocladius by its long L4 tufts.