Subiasella (Subiasella) extrema, Mahunka, 2008

Mahunka, S., 2008, A New Genus And Some Other Data Of Oribatids From Thailand (Acari: Oribatida), Acta Zoologica Academiae Scientiarum Hungaricae 54 (2), pp. 125-150 : 138-139

Subiasella (Subiasella) extrema sp. n.

( Figs 28–31 )

Diagnosis: Prodorsum with some longitudinal lines such as a short costular and a distinct lateral lines. Two pairs of large maculae in the interbothridial region. Bothridium with long posteromarginal tubercles; sensillus well dilated, fusiform, barbed at its distal margin. Notogastral setae short, mostly straight. Apodemata and epimeral borders partly weakly developed, bo. 4. framing posteriorly the genital aperture. Setae of genito-anal region, except for long setae ad 1 and ad 2 short, simple.

Material examined: Holotype: Thailand, Province Prachin Buri, Sakaerat Research Station , 15. 06. 2001. Leg. E. HORVÁTH & GY . SZIRÁKI (As-804). Three paratypes from the same sample. Holotype (1747-HO-07) and two paratypes (1747-PO-07): HNHM , one paratype: MHNG .

Measurements: Length of body: 222–247 µm, width of body: 100–122 µm.

Prodorsum: Rostral part of prodorsum widely rounded, without distinct apex. Rostral setae arising on its dorsal surface and a pair of very short costulae and some weak transversal lines are observable ( Fig. 28 ). A pair of well sclerotised lateral laths also present, along them the surface ornamented by fine ribs ( Fig. 31 ). Two pairs of interbothridial maculae, between them a short, weak crest visible. Bothridium large, with long posterior tubercles. Sensillus short, directed mostly backwards, its head wide, with short bristles on its posterior margin.

Notogaster: Elongate. A pair of long, well developed crests present. Ten pairs of setiform, characteristically straight notogastral setae present, setae c 2 much shorter than others.

Lateral part of podosoma: Exobothridial region without small tubercles, but well sclerotized; a large protuberance behind the bothridium and a longitudinal crest bearing the exobothridial setae observable ( Fig. 30 ). Pedotecta 1 well visible.

Ventral parts ( Fig. 29 ): Epimeral region well framed by crests anteriorly, its surface with irregular pattern. Sejugal and posterior apodemata and epimeral borders well developed, bo.4 running behind the genital aperture. Anterior part of sternal apodema reduced, its posterior part present. One pair of strong tuberles bearing setae 3b visible in the sejugal region. Epimeral setae varying in length. Genital, aggenital, anal and adanal setae ad 3 short, while ad 1 and ad 2 much longer than former setae. Lyrifissures iad in direct apoanal position.

Legs: All normal oppioid type. Solenidium ϕ 1 arising on a well developed process of tibia I.

Remarks: The new species is characterised first of all by some peculiar features first of all by the shape of the apodeme furthermore by the prodorsal pattern and the conspicuously large head of the sensillus. On this basis it was not relatable, to any of the heretofore known species in this genus.

Etymology: The new species is named after the conspicuous form of the apodemata and epimeral borders.

Figures

Figs 28–31. Subiasella (Subiasella) extrema sp. n. – 28 = body in dorsal view, 29 = body in ventral view, 30 = anterior part of prodorsum in lateral view, 31 = basal part of the prodorsum