Oudemansia Schött, 1893

Palacios-Vargas, José G. & Bu, Yun, 2020, New records of Collembola from marine littoral sand of Hainan Island, China with description of a new Oudemansia species (Neanuridae: Pseudachorutinae), Zootaxa 4810 (1), pp. 117-130 : 118-119

Genus Oudemansia Schött, 1893

Type species: Oudemansia coerulea Schött, 1893

Diagnosis. General aspect like Pseudachorutes . Labrum elongated, forming a beak with long distal setae, short proximal setae, with a total of 11–13 setae. Labium truncate. Hypopharynx well developed, bifid at the apical end. 8 eyes on each side, in three groups (4, 1 and 3), 3 ocular setae, postantennal organ absent. Mandible with one or two longitudinal rows of teeth on median edge. Maxilla styliform. Ant. III organ with two relatively long microsensilla, not in a groove, not covered by cuticular fold, guard sensilla short. Dorsal guard sensillum migrated towards Ant. IV. Ant. IV with trilobed apical bulb and one apical organite; ms absent. Usually with few cylindrical sensilla, no ventral sensorial file. Body chaetotaxy composed of only two rows of short smooth setae on each segment. Sensorial setae long. Body sensorial setae on Th. II and III are m6 and p4; on Abd. I–IV on p5, in Abd. V on p3. Some species with pseudocelli well developed on head, posterior to eye patch, and on Abd. I, III, and IV. No capitate tenent hairs on tibiotarsi. Claw moderately long, untoothed or armed with inner and/or lateral teeth. Ventral tube with 2 + 2 to 4 + 4 setae. Retinaculum with 3 + 3 teeth. Furcula short but well developed, mucro and dens fused, with 5–6 dental setae on posterior side. Abd. VI with 2–4 spines or spiniform setae. Colour black, dark blue, blue-red or purple. Length 0.8–2.0 mm. Inhabitants of marine littoral environments. ( Delamare Deboutteville & Massoud, 1964).

Distribution. Indonesian Archipelago, Vietnam, Japan, China, Madagascar, Australia and United States of America.

Remarks. This is the only genus in the Subfamily Pseudachorutinae with anal spines. Mouthparts are very complex and the hypopharynx well developed; eyes separated in 3 groups. All members of this group are marine littoral inhabitants. There is a strong reduction of cephalic chaetotaxy and of body, with only two rows of setae on each segment.