Brundin, 1956
Body
Small larvae up to 3,6 mm long (Cranston and Saether, 1982). Living larvae are greenish, blueish or purplish (Moller Pillot, 1984b). The L4 setae of the abdomen are short and simpel. The anterior and posterior parapods and procercus are present.
Head
The head length is 0.265 - 0.344 mm (Cranston and Saether, 1982).
Antenna
The antenna consists of four or five segments. Lauterborn organs absent. The small third segment (of A. submontanus) is unclearly separated from the second segment with a small apical coronet. In A. submontanus the fourth segment is much longer than the third (Moller Pillot, 1984b) Acam antenna. In A. reissi the third segment is subequal to the fourth (Cranston and Saether, 1982) Acamptocl reissi antenna9.
Mentum
The pale mentum is very characteristic in having three small teeth only. The dorsomentum consists of a plate with an outer row of 12 - 16 teeth. Beard absent (Cranston and Saether, 1982; Wiederholm, 1983; Moller Pillot, 1984b) Acam mentum.
Labrum
The pecten epipharyngis consists of three spines, SI simpel, premandible with four teeth (Wiederholm, 1983).
Mandible
The mandible has a long distal tooth and four small teeth within. Seta interna is short with 4 - 5 simpel branches (Cranston and Saether, 1982; Wiederholm, 1983).
Differential characteristics
In the subfamily Orthocladiinae there is no genus with a mentum resembling Acamptocladius. Also the dorsomental plates are unique Acam mentum.
Diversity
European species: 2
Treated species:
Acamptocladius reissi
Acamptocladius submontanus