Kieffer, 1906
Body
Large larvae up to 15 mm long. The head often (P. olivacea) with a large black spot Prodiam oliv head ventral. Body setae pale and indistinct. The anterior and posterior parapods are separate and bear rows of claws. Procercus is about twice as high as wide with 8 anal and 2 subapical setae. Two pairs of anal tubules present (Wiederholm, 1983).
Head
Antenna
The antenna consists of four segments. The first segment is long and segments 3 and 4 are small. The blade is longer than the flagellum. Lauterborn organs are small but distinct.
Mentum
The mentum has two low median teeth and 7-8 pairs of lateral teeth including the 1 or 2 small teeth of the first lateral pairs. The ventromental plates are very large and resemble those of Chironomini Prodiam oliv mentum. A beard with a fringe of very long hairs may be present (P. olivacea) or absent (P. rufovittata).
Labrum
The pecten epipharyngis consists of three scales, SI is serrate distally and the 2 labral lamellae broad and pectinate. The premandible has 2 apical teeth (Wiederholm, 1983).
Mandible
The mandible has an apical tooth and 4 inner teeth. The seta interna has serrate branches (Wiederholm, 1983).
Differential characteristics
The characteristic dark spot ventrally on the head (P. olivacea) Prodiam oliv head ventral, very large ventromental plates in combination with a normal mandible and 7-8 pairs of lateral mental teeth are distinctive for Prodiamesa Prodiam oliv mentum.
Diversity
European species: 4
Treated species:
Prodiamesa olivacea
Prodiamesa rufovittata