Eutegaeus soror P. Balogh, 1985

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 : 27-28

Eutegaeus soror P. Balogh, 1985

( Fig. 11 )

Eutegaeus soror P. Balogh, 1985, p. 86 .

Dimensions. Holotype female length 1,178 μm, breadth 704 μm. Ratio of prodorsum to total length: 0.36 (holotype). Topotypes: females (n = 6): mean length 1,065 μm (range 1,027 –1,122 μm), mean length 774 μm (range 718–814 μm); males: length 940 μm and 963 μm, breadth 727 μm and 798 μm.

Redescription of adult. The holotype specimen of Eutegaeus soror is badly damaged and missing the genital and anal plates as well as the notogastral and lamellar setae. Accordingly, the redescription below is supplemented by reference to topotypic material, collected within 18 km of the type locality from identical microhabitat (leaf litter) in the same vegetation community (sub-tropical rainforest).

Prodorsum: rostrum acute; rostral setae (ro) reflexed, smooth. Lamellae broad, separated medially, parallel, lateral margins conspicuously convex, translamella absent.Lamellar setae (le) smooth, curved, overlapping, emerging from well-developed cup-shaped incisions, each flanked by long sharp teeth of equal size; lamellar cusps extending anteriorly beyond rostrum ( Fig. 11a ). Interlamellar setae (in) at least twice as long as setae le, recurved; marked invagination laterally at base of lamella anterior of bothridium. Bothridia projecting laterally to inner margins of humeral processes, openings angled anterolaterally, posterior margin with anterior condyles of enantiophyses H in form of prominent V-shaped flange; anterior margin with rounded protuberance. Bothridial setae long, setiform, smooth.

Notogaster: with thin cerotegument; ratio of length to breadth: 0.81; notogaster rounded, convex. Humeral processes broad, without dorsal keel; waisted at their bases, then expanding and sharply pointed apically, extending to point level with middle of lamella ( Fig. 11a ). Short, sharp lateral projection on notogaster posterolateral of humeral process. With eight pairs of long, flagelliform, smooth notogastral setae, l series, h 2, h 3 and p series present: la and lm in centrodorsal position, lp and h series in sub-marginal position; h 2 longer than others, which are sub-equal in length; p 1 markedly longer than others in p series; notogastral margin with irregular flat tubercles.

Ventral aspect: subcapitulum acute apically; mentum as long as broad; subcapitular setae smooth, setae m and h each twice as long as a ( Fig. 11b ). Tutorium short, blunt, not well-developed, barely visible in ventral aspect. Epimeral plates discrete except IV, all broadly separated in midline, sub-rectangular, plates II slightly shorter than others; epimeral setation 3-1-3-2; setae on plates III clustered. Pedotectum I (pd I) slight, sub-rectangular in lateral outline, with short blunt spur apically; pd II small, pointed; discidium triangular with sharp point. Ventral plate broader than long. Genital and anal plates separated by distance about half length of genital plates; genital plates 148 µm long, with six pairs of setae sub-equal in length, g 4 displaced laterally; lyrifissure iad in para-anal position, some distance from anal plate, more than its length. Anal plates lozenge-shaped, 272 µm long; setae of the ad series very long, at least twice length of setae p 2. Pre-anal organ (po) T-shaped.

Material examined and locality data. Holotype female, ANIC accession no. 53-638, leaf litter, rainforest, Lynchs Creek, Airdrop Road, Wiangaree State Forest , New South Wales, 28°23’S, 153°03’E, 820 m, coll. V. J. Pattemore . Topotypes: six females, two males, ANIC 460 , leaf 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 .

Diagnosis. Eutegaeus soror can be distinguished from other species in the genus by the following combination of characters: (1) the absence of a translamella; (2) the presence of the anterior condyle of enantiophysis H; (3) the short tubercle-like projection on the anterior margin of the bothridium; (4) the sharp lateral projection on the notogaster posterolateral of the humeral process; (5) the extremely long, flagelliform interlamellar setae and notogastral setae of the l and h series; (6) the relatively small pedotectum I with a short apical spur; (7) the short, pointed pedotectum II; (8) the three setae on epimeral plate III clustered in a group on the medial part of the plate; (9) the relatively long setae p 1 but with setae p 2 and p 3 considerably shorter; (10) the very long adanal setae, at least twice as long as p 2 and p 3.

Remarks. Eutegaeus soror is morphologically most similar to E. bidhawal , as detailed above. P. Balogh (1985) considered E. soror belongs to a species group containing E. stylesi and E. radiatus from New Zealand, characterised by very long setae p 1, very short setae p 2 and p 3 and deeply incised lamellar cusps. Eutegaeus pinnatus from New Zealand, also has these character states. However, setae p 1 in the three New Zealand species are on short tubercles whereas such tubercles are absent in E. bidhawal and E. soror .

Figures

FIGURE 11. Eutegaeus soror P. Balogh, 1985, adult (a) dorsal aspect; (b) ventral aspect. Scale bar = 500 μm.