Scapheremaeus anteriorugosus, Mahunka, 2011

Mahunka, S., 2011, New And Little Known Oribatid Mites From Madagascar (Acari: Oribatida) Ii., Acta Zoologica Academiae Scientiarum Hungaricae 57 (1), pp. 1-21 : 11-13

Scapheremaeus anteriorugosus sp. n.

( Figs 21–23 )

Diagnosis. Rostral part wide, rostrum widely rounded. Very short costulae and a well developed transcosula present, bearing short apophyses of lamellar setae. Whole surface of prodorsum covered by irregular rugae. Interlamellar setae present. Notogaster without long humeral apophyses, lenticulus well-developed, centrodorsal plate oval, covered with large, irregular alveoli, circumdorsal scissure complete. Ten pairs of notogastral setae, p series dilated. Six pairs of genital setae present. Lyrifissures iad located in anterior corner of ano-adanal aperture.

Material examined. Holotype: Madagascar, Toamasina Province. Maromizaha forest . 26. August 1998. Leg. Dr. T. Pócs (9878) (Afr-921). Holotype (1814-HO-10) deposited in the HNHM .

Measurements: Length of body: 305 µm, width of body: 165 µm.

Prodorsum: rostrum very wide, without median cusp. Anteromedian margin nearly straight or slightly rounded Rostral setae comparatively long, thin, smooth and setiform, bent inwards, arising ventrally. Costulae very short, connected with a well observable transcostula. Transcostula bearing two apophysis with short, bacilliform lamellar setae. In front of transcostula parallel crest present. Rostral and interlamellar surface ornamented with well sclerotised striae in irregular position. narrow region with mainly longitudinal ribs present between bothridia. This region bordered by narrow striae anteriorly. Sensillus wide, club-shaped, darkly-pigmented. Interlamellar setae minute, arising very near to bothridia.

Notogaster: Humeral process absent, tuberculate, without extension ventrally. Lenticulus round, well observable, beside it some irregular ribs present. Centrodorsal plate completely separated by the circumdorsal scissure. Centrodorsal plate ornamented with large alveoli, with a weak V-shaped ridge in caudal region. Lateral circumnotogastral plate plicate. Ten pairs of notogastral setae present, two pairs (lm and lp) located in the circumdorsal scissure. Anterior notogastral setae short, straight, bacilliform, some posterior setae covered by cerotegument layer, club shaped. Lyrifissures not or badly visible on account of the similar plicate-like structure.

Lateral part of podosoma: Tutorium well-developed, lateral carina. Pedotectum I and II small, not covering the acetabula.

Ventral parts: Subcapitulum visible, diarthric, setae h minute, surface smooth. All epimeral setae not examinable, visible setae very short, slightly bacilliform. Six pairs of setiform genital setae present, aggenital and anal setae minute. Three pairs of adanal setae, all short and minute, all three pairs locates along the posterior margin of ano-adanal aperture, setae ad 1 stand very near to each other. Lyrifissures iad in para-anal position.Ventral plate with weak radially located striae.

Legs: All legs destroyed, not observable.

Remarks: This is the first record of the genus Scapheremaeus BERLESE, 1910 in Madagascar. The species of the genus belong to several species groups (COLLOFF 2009). On the basis of the ten pairs of notogastral setae, the absence of the lateral carinae of the prodorsum, the short and poorly developed lamellae, and the short lamellar setae and their short basal apophyses the new species belongs to the “pterosus” group. However the new species has a very short humeral apophysis (very long in S. palaciosi Rios, 1996 , S. taurus BALOGH, 1970 and S. yamashitai Aoki, 1970 ). S. anteriorugosus has long and well developed ribs-like anterior prodorsal sculpture (they are short and foveolate, sometimes nearly smooth in S. guerini (BERLESE, 1908) , S. petrosus Sitnikova, 1975 and S. johnsi BALOGH, 1970 ). S. anteriorugosus sp. n. also can be distinguished from other species by the form of the notogastral setae, which are very short, with some partly rounded in the new species, and its median notogastral sculpture, which consists of very large alveoli.

Etymology: The species name refers to the sculpture of the anterior part on the prodorsum.

Figures

Figs 21–23. Scapheremaeus anteriorugosus sp. n.: 21 = body in dorsal view, 22 = body in ventral view, 23 = prodorsal sculpture