Porrhotegaeus ornatus J. Balogh & Mahunka, 1966

Colloff, Matthew J., 2023, The oribatid mite superfamily Eutegaeoidea (Acari, Oribatida), with descriptions of new taxa from Australia and New Caledonia and a re-assessment of genera and families, Zootaxa 5365 (1), pp. 1-93 : 76-78

Porrhotegaeus ornatus J. Balogh & Mahunka, 1966

( Fig. 40 )

Porrhotegaeus ornatus J. Balogh & Mahunka, 1966, p. 557 .

Dimensions. Holotype female length 1,020 μm, breadth 806 μm. Non-type material: females (n = 8): mean length 1,111 μm (range 1,082 –1,178 μm); mean breadth 867 μm (range 806–909 μm); males (n = 3): mean length 1,034 μm (range 1,024 –1,049 μm); mean breadth 849 μm (range 844–858 μm).

Redescription of adult. Prodorsum: rostrum acute, rounded; rostral setae (ro) long, thin, smooth, on short tubercles. Lamellae broad, with fine striate microsculpture dorsally, becoming reticulate ventrally, lateral margins strongly convex; cusps broadly separated medially, medial edge concave, with single sharp apical tooth; lamellar setae (le), relatively short, thin, smooth, emerging from ventral surface of lamellar cusp near apex ( Fig. 40a ). Bothridia long, corniculate, extending beyond lateral margins of lamellae, with slight fold anterior of bothridium; bothridial seta long, smooth, bacilliform, pointed. Posterior margin of prodorsum with anterior condyle of postbothridial enantiophysis B.

Notogaster: ratio of length to breadth: 0.79; notogaster flat, smooth, without obvious cerotegument. Humeral process long, with striate microsculpture, pointed, reflexed ventrally, lateral margin straight; medial margin strongly serrated, convex: incised and folded over cuticle of basal part of process ( Fig. 40a ). Lyrifissures ia and im not visible. With nine pairs of long, marginally-positioned setae with fine spines, projecting vertically; with complete l, h and p series (h 1 is present); setae p 2 and p 3 smooth, p 2 as long as h series, p 3 shorter; p 1 positioned dorsally and same length as l and h series.

Ventral aspect: subcapitulum elongated, narrow; subcapitular setae h extremely long, thin; a and m shorter. Chelicerae chelate-dentate and of normal proportions. Tutorium broad, curved, with sharp apex, margin serrated, microsculpture reticulate ( Fig. 40b ). Epimeral plates not discrete in midline, sub-rectangular to trapezoid, plates I and II large, plates III extremely narrow, plates IV sub-ovoid, smaller than others; epimeral setation 3-1-3-2; setae well-developed, 1b longer than others. Apex of pedotectum I (pd I) horn-shaped; pd II broad, rectangular, protruding laterally; pd I and II with reticulate microsculpture; discidium straight, acutely pointed apically; faint perigenital carina (pc) and posterior tubercles of enantiophysis E4 present. Ventral plate ovoid, broader than long. Genital and anal plates separated by distance of a third of length of genital plates; genital plates 119 µm long, with six pairs of short setae sub-equal in length, aligned longitudinally; three pairs of long, thin adanal setae; lyrifissure iad in para-anal position, some distance from anal plate, more than length of iad. Anal plates lozenge-shaped, 136 µm long. Pre-anal organ (po) T-shaped.

Material examined and locality data. Holotype female, ANIC accession no. 53-000665, Murwillumbah, New South Wales, coll. J. Balogh, 7.iii.1965 . Non-type material: three females, ANIC 460 , litter, Nothofagus moorei rainforest, O’Reilly’s Rainforest Retreat, Lamington National Park , Queensland, 28°14'S, 153°08'E, 920 m., coll. R. J. Kohout, 21.iii.1973. Four females, ANIC 655 A, litter, Nothofagus moorei rainforest, O’Reilly’s Rainforest Retreat, Lamington National Park , Queensland, 28°14'S, 153°08'E, 920 m., coll. J. Lawrence and T. Weir, 22- 27.xi.1978. Two females, one male, ANIC 771 , litter under Nothofagus moorei , Wiangaree State Forest , New South Wales, 28°23’S, 153° 4’E, 1,050 m., coll. T. Weir and A. Calder, 10-12.ii.1983. One female, ANIC 772 , same data as ANIC 771.

Remarks: Porrhotegaeus ornatus has some morphological similarities with P. githabul , as outlined above. However, it and P. herminae share the faint perigenital carinae which are absent in the two other Porrhotegaeus species. Porrhotegaeus ornatus is the only member of the genus with the anterior condyles of enantiophyses B. Further, P. ornatus differs from P. herminae in that pedotectum II in the latter species is extremely large, leaf-shaped and striated, whereas that in P. ornatus is rectangular and reticulate. Also, in P. herminae the adanal setae are much shorter than those of P. ornatus , the lamellar cusps lack an apical tooth and the humeral processes are not striated.

J. Balogh and Mahunka (1966, Fig. 5 therein) illustrated P. ornatus with a translamella. However, the holotype lacks a translamella, consistent with the other three species in the genus. Also, the serrated medial margins of the humeral processes, the anterior condyles of enantiophyses B and the faint perigenital carinae were not shown in the original description and the setae of the l and h series were illustrated as emerging from the ventral surface of the notogastral margin instead of the dorsal surface.

Porrhotegaeus ornatus was recorded at Murwillumbah and Barrington Tops, New South Wales, and at Beechmont, Queensland, by Hunt et al. (1998b).

Figures

FIGURE 5. Eutegaeus nothofagii sp. nov., adult (a) dorsal aspect; (b) ventral aspect; (c) detail of cerotegument on notogaster. Scale bars: (a, b) = 200 μm; (c) = 20 μm.

FIGURE 40. Porrhotegaeus ornatus J. Balogh & Mahunka, 1966, adult (a) dorsal aspect; (b) ventral aspect. Scale bar = 200 μm.