Theinemann, 1924
Body
Small to medium sized to large larvae up to 6 mm long. Living larvae are yellowish to greenish. The anterior and posterior parapods are separate and bear rows of claws. The anal segment is placed ventrally on the preanal segment, thus forming a more or less right angle with the body axis Parapha impensus anal segm. The procercus is very small and two pairs of anal tubules are present (Wiederholm, 1983; Moller Pillot, 1984b).
Head
The head length is 0.25-0.33 mm. The smaller eye is placed ventrally of the larger one instead of distally Paraphaenocladius eye.
Antenna
The antenna consists of five segments, segment 3 usually shorter than segment 4. The blade is as long or longer than the flagellum. Lauterborn organs very large Parapha impensus antenna 8.
Mentum
The mentum has one Parapha pseudirr mentum 8 median tooth (slightly subdivided in P. impensus Parapha impensus mentum9) and 5 pairs of lateral teeth. The ventromental plates are distinct but do not cover any teeth of the mentum. The beard is absent. The setae submenti are close to the mentum.
Labrum
The pecten epipharyngis consists of three short spines, SI is plumose and the labral lamellae are fused to form a plate with a smooth of serrated tip. The premandible has three apical teeth (Wiederholm, 1983; Moller Pillot, 1984b).
Mandible
The mandible has an apical tooth and 3 inner teeth. The seta interna has simpel or serrate branches (Wiederholm, 1983).
Differential characteristics
The combination of two eyes on top of each other and the more or less right angle between the anal segment and the body axis are distinctive.
Diversity
European species: 8
Treated species:
Paraphaenocladius exagitans-monticola
Paraphaenocladius impensus
Paraphaenocladius penerasus
Paraphaenocladius pseudirritus