Beckiella costulata, Mahunka, 2006

Mahunka, S., 2006, Oribatid Mites (Acari: Oribatida) From Venezuela, Ii. New Or Rare Species From Montane Forests, Acta Zoologica Academiae Scientiarum Hungaricae 52 (3), pp. 271-286 : 272-273

Beckiella costulata sp. n.

( Figs 1–5 )

Diagnosis: Lamellae conspicuous, strongly developed. Prodorsal surface – except the interlamellar part – smooth. Sensillus long, directed laterally, its head lanceolate. Dorsosejugal suture absent, nine pairs of short notogastral setae present. Epimeral setae – except 1c, 3c and 4c – very short. Tarsus of leg IV with large, triangular elevation.

Material examined: Holotype: Estado Mérida, Parc Nacional Sierra Nevada. Andean montane rainforest dominated by Decussocarpus ( Podocarpaceae ) near the cable car station La Montaña. At 2460 m. alt. Litter and mosses. 15. Febr. 1997. Coll. S. & T. PÓCS (No. 97121). 5 paratypes from the same locality. Holotype (1701-HO-05) and 4 paratypes (1701-PO-05): HNHM 2, 1 Paratypes: MHNG 3.

Description: Measurements: Length of body: 612–737 µm, width of body: 225–300 µm.

Prodorsum: Rostral apex slightly elongated. Prodorsum with well-developed, slightly curved costulae, nearly parallel, not far from each other ( Fig. 5 ), they reach beyond the insertion of lamellar setae ( Fig. 4 ) with distal end directed outwards. Interlamellar region and the surface of costulae foveolate. Rostral and lamellar setae setiform, distinctly barbed, interlamellar and exobothridial setae simple, thin and smooth. Sensillus long, directed slightly backwards and outwards; head simply lanceolate, smooth.

Notogaster: Dorsosejugal suture reduced, in its place only very thin lines visible ( Fig. 1 ). Nine pairs of short notogastral setae present, setae c 2 absent. Setae la and lm setiform, smooth, lp, h 1 and h 2 spiniform, pilose, the remaining setae bacilliform, smooth. No essential difference in their length, only setae h 3 shorter than setae p 1 – p 3.

Lateral part of podosoma: Tutorium short, pedotectum 1 small.

Ventral parts ( Fig. 3 ): Infracapitulum with a small hollow anteromedially. Epimeral setal formula: 1–0–2–3. Setae 1c much longer than the remaining ones, curving backwards. Some apodemes and borders well, others weakly developed. Longitudinal one well visible. Epimeral borders framing the epimeal region posteriorly conspicuously wide. All setae in the anogenital region short, setae ad1 and ad2 bacilliform, all others setiform.

Legs: Tarsus IV with a pair of large, sharply pointed elevation ( Fig. 2 ).

Remarks: The new species is well characterised by the form of the wide and well-sclerotised lamellae. On this basis the new species belongs to species group of Beckiella reticulofemorata BALOGH et MAHUNKA, 1982 , along with B. opposita MAHUNKA, 1982 , B. fratercula BALOGH et MAHUNKA, 1978 , etc. The new species is distinguished from all congeners by the conspicuous length of lamellae.

Etymology: Named after the well-developed prodorsal costulae.

1 Serial number of the collectors.

2 HNHM: deposited in the Hungarian Natural History Museum, Budapest, with identification number of the specimens in the Collection of Arachnida.

3 MHNG: deposited in the Muséum d’Histoire Naturelle, Geneva.

Figures

Figs 1–5. Beckiella costulata sp. n.: 1 = body in dorsal view, 2 = leg IV, 3 = body in ventral view, 4 = rostral part of the podosoma in lateral view, 5 = rostral part of the podosoma in dorsal view