Johannsen, 1905
Body
Medium sized larvae with a length up to 12 mm. Living larvae are yellowish and may have brown spots which turn pink in conserved specimens. Fringe of swimming hairs absent (Wiederholm, 1983; Moller Pillot, 1984a).
Head
The head length is 0.9 - 1.5 mm with a cephalic index of 50-65 (Moller Pillot, 1984a).
Antenna
The antennal segments are all yellow and the antennal ratio is 3.8 - 7. The ring organ is situated at 0.5 - 0.6 of the height of the first segment. The second segment is normal and lacks a tuning fork (Wiederholm, 1983; Moller Pillot, 1984a).
Mentum
Dorsomentum without teeth.
Ligula and paraligula
Ligula with 5 brown teeth in a concave row. Paraligula with a long outer tooth and a much smaller inner tooth Abl ligula paraligula.
Mandible
The mandible has a large basal tooth.
Maxilla
The maxilla is very long with the basal segment of the maxilla is subdivided in 2 - 6 segments Abl longistyla maxilla Abl phatta maxilla.
Anal tubules
4 anal tubules which are longer than wide.
Posterior parapods
Some claws on posterior parapods may be brown Abl claw. No teeth on the inner margin.
Differential characteristics
In the tribe of the Pentaneurini with a concave row of ligula teeth Abl ligula paraligula, Ablabesmyia differs from all other genera in having a long maxilla with a subdivided basal segment Abl longistyla maxilla Abl phatta maxilla. The brown claws amidst the yellow ones on the posterior parapods is a shared character with Monopelopia, Rheopelopia and Xenopelopia.
Diversity
European species: 4
Treated species:
Ablabesmyia longistyla
Ablabesmyia monilis
Ablabesmyia phatta