Eutegaeus bidhawal, Colloff, 2023

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 : 21-23

Eutegaeus bidhawal sp. nov.

( Fig. 7 )

Dimensions. Holotype female length 1,094 μm, breadth 896 μm. Paratype females (n = 4) mean length: 1093 μm (range: 1,077 –1,132 μm); mean breadth: 851 μm (range: 821–901 μm). Paratype male length: 1,012 μm, breadth 778 μm. Ratio of prodorsum to total length: 0.33 (holotype).

Description of adult. Prodorsum: rostrum acute; rostral setae (ro) curved, smooth, on short tubercles, not visible in dorsal aspect. Lamellae broad, separated medially, parallel, lateral margins conspicuously convex, without a translamella. Lamellar setae (le) smooth, curved, extending well beyond apices of rostral setae, emerging from well-developed cup-shaped incisions, each flanked by two short sharp teeth of equal size; lamellar cusps extending well beyond rostrum ( Fig. 7a ). Interlamellar setae (in) on posteromedial margin of lamellae, at least four times length of setae le, extending well beyond rostrum and apices of setae le. Bothridia projecting laterally almost to inner margins of humeral processes, openings angled anterolaterally, posterior margin convex, lacking anterior condyle of enantiophysis H. Bothridial setae long, curved, bacilliform, smooth, pointed.

Notogaster: with thin granular cerotegument; ratio of length to breadth: 0.9; notogaster rounded, convex. Humeral processes narrow, with dorsal keel, waisted at their bases, expanded then pointed apically, extending anteriorly to point level with middle of lamella ( Fig. 7a ). Short, sharp lateral projection bearing lyrifissure ia on notogaster posterolateral of humeral process. With eight pairs of notogastral setae, l series, h 2, h 3 and p series present, l and h series in sub-marginal positions, flagelliform, smooth, very long (at least 250 μm); lm slightly shorter than others ( Fig. 7c ); bases of setae h 2 same distance apart as those of p 1; setae of p series much shorter than l and h series, p 1 longer than p 2 and p 3.

Ventral aspect: subcapitulum acute apically; mentum as long as broad; subcapitular setae short, smooth, setae m twice as long as a and h ( Fig. 7b ). Tutorium broad, right-angled. Epimeral plates discrete, all broadly separated in midline, sub-rectangular to trapezoid, plates II shorter than others; epimeral setation 3-1-3-2; setae 3a and 3b longer than others. Pedotectum I (pd I) well-developed, with large, conical anterior lobe and sub-rectangular posterior lobe; pd II small, acutely pointed; discidium with sharp point. Ventral plate broader than long. Genital and anal plates separated by distance about half length of genital plates; genital plates 173 µm long, with 6 pairs of setae, g 5 displaced laterally, g 1 longer than others; lyrifissure iad in para-anal position, some distance from margin of anal plate same as seta ad 3. Anal plates lozenge-shaped, 276 µm long; setae of the ad series very long; longer than setae p 2. Pre-anal organ (po) T-shaped.

Type designation, material examined and locality data. Holotype female, ANIC accession nos. 53-1036; paratypes: one male, two females, ANIC accession no. 53-1037, moss on Sassafras ( Atherosperma moschatum ), rainforest, 1,077 m., Errinundra Saddle, Errinundra National Park, Victoria, 37°19’S 148°51’E, 1,030 m., coll. M.J. Colloff, 29.ix.2009. Paratypes: two females, ANIC accession no. 53-1038, moss ( Dicranoloma billiardieri ), Nothofagus cunninghami rainforest, The Beeches, Lady Talbot Drive near Warburton, Yarra Ranges National Park, Victoria, 37°29’S, 145°50’E, 800 m., coll. G. Perdomo, May, 2009.

Etymology. The specific name is a noun in apposition. The species is named for the Bidhawal People of Gippsland and the Errinundra Plateau on whose traditional land this species was found.

Diagnosis. Eutegaeus bidhawal can be distinguished from other species in the genus by the following combination of characters: (1) the absence of a translamella; (2) the prominent, sharp lateral projection on the notogaster; (3) the long, flagelliform interlamellar setae (4) the long, flagelliform setae of the l and h series; (5) the prominent, sub-rectangular pedotecta I with lobed apices; (6) the short, pointed pedotecta II; (7) relatively long setae p 1 but with setae p 2 and p 3 considerably shorter; (8) the very long adanal setae.

Remarks. This species shares with E. soror (cf. below) the very long flagelliform interlamellar setae and notogastral setae of the l and h series. However, the l and h setae are shorter in E. soror , which also has lamellae cusps with reticulate microsculpture, a V-shaped flange on the posterior margin of the bothridium, the bases of setae h 1 positioned further apart than those of setae p 1, the genital setae sub-equal in length, setae on epimeral plates III clustered medially instead of spaced along the length of the plate as in E. bidhawal , with small tutoria and small pedotecta I with a short apical spur, rather than the broad, right-angled tutoria and prominent lobe-shaped pedotecta I of E. bidhawal .

Figures

FIGURE 7. Eutegaeus bidhawal sp. nov., adult (a) dorsal aspect; (b) ventral aspect. Scale bar = 200 μm.