Neoeutegaeus phyllophorus J. & P. Balogh, 1983

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 : 51-54

Neoeutegaeus phyllophorus J. & P. Balogh, 1983

( Figs. 26 , 27 )

Neoeutegaeus phyllophorus J. & P. Balogh, 1983b, p. 291.

Neoeutegaeus sp. : Hunt et al., 1998.

Dimensions. Holotype male: length 281 μm, breadth 196 μm. Ratio of prodorsum to total length: 0.42.

Redescription of adult. The holotype specimen of Neoeutegaeus phyllophorus is badly damaged and missing the anal plates, the bothridial, notogastral and lamellar setae. Accordingly, the redescription below is supplemented by reference to topotypic material, collected within 20 km of the type locality from identical microhabitat (leaf litter) in the same vegetation community (sub-tropical rainforest).

Prodorsum: rostrum acute apically; rostral setae (ro) extremely short, smooth, not visible in dorsal aspect. Lamellae broad, extending anteriorly well beyond rostrum, separated medially, lateral margins convex with a small invagination anterior of bothridium ( Fig. 26a , 27a ). Lamellar seta (le) short, curved medially, with fine spines, emerging on short apophysis, with shallow invagination and small tooth medially; medial margins of cusps parallel, with complete translamella. Interlamellar setae (in) minute, close together. Bothridia elongate, corniculate, projecting laterally beyond inner margins of humeral processes, openings angled anterolaterally. Bothridial seta long, head club-shaped, with fine spines. Anterior condyle of post-bothridial enantiophyses B on posterior margin of prodorsum.

Notogaster: ratio of length to breadth: 0.86; notogaster rounded, convex. Humeral processes long, straight, parallel, triangular, pointed, with dorsal keel, extending to point level with translamella; lateral margin expanded where process joins anterior margin of notogaster forming slight projection ( Fig. 26a ). Lyrifissures not visible. With eight pairs of sub-marginal notogastral setae, l series and h 2 and h 3 smooth, curved, short, pointed, sub-equal in length ( Fig. 26a ), covered in cerotegument; p series very short, setiform, not visible in dorsal aspect.

Ventral aspect: subcapitulum broad; subcapitular setae h extremely short, on anterior margin of mentum; setae a at least twice their length; mentum much broader than long, with fine, granular microsculpture ( Fig. 26b , 27b ). Tutorium very broad, pointed. Epimeral plates I-II discrete, broadly separated in midline, plates I massive, as broad as long; plates III shorter and narrower than others; with triangular median strip of cuticle between plates I and pair of epimeral foveolae (ef) at its base and second pair between plates II and III; epimeral setation 3-1-3-2; setae very short, sub-equal in length. Pedotectum I (pd I) well-developed, rectangular in lateral outline; pd II very long and broad; lateral margins sloped obliquely; discidium broad, rounded apically; perigenital carina and enantiophysis E4 present. Ventral plate ovoid, markedly broader than long. Genital and anal plates separated by distance of less than half length of genital plates; genital plates longer than anal plates: 36 µm long, with five pairs of short setae sub-equal in length, g 3 displaced laterally; three pairs of short adanal setae; lyrifissure iad in para-anal position, some distance from margin of anal plate, about same as distance of bases of seta ad 2 from plate. Anal plates sub-rectangular, 33 µm long. Pre-anal organ (po) oval.

Material examined and locality data. Holotype male, ANIC accession no. 53-00637, litter, Nothofagus moorei rainforest, Point Lookout, near Ebor, New England National Park, New South Wales, 30°29'S, 152°25'E, 1,525 m, coll. I. Naumann, 25.iv.1973. Non-type material: three males, four females, ANIC 836, litter, closed forest, Gibraltar Range National Park, New South Wales, 29°31'S, 152°22'E, 920 m, coll. L. Hill, 14.vi.1982. One adult female, ANIC 754, Nothofagus and Sassafras ( Atherosperma moschatum ) litter, Nothofagus moorei forest, Cobark Forest Park, Barrington Tops, New South Wales, 31°59’S, 151°49’E, coll. T. Weir and A. Calder, 15.xi.1981. Eight females, two males, ANIC 459, litter, Nothofagus moorei rainforest, O’Reilly’s Rainforest Retreat, Lamington National Park, Queensland, 28°14’S 153°08’E, 920 m, coll. R.W. Taylor, 21.iii.1973. Six females, two males, 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.

Diagnosis. Neoeutegaeus phyllophorus can be distinguished from other species in the genus by the following combination of characters: (1) the long lamellar seta with spinose ornamentation; (2) the lamellar seta emerging from a short apophysis, with a shallow invagination and a small tooth medially; (3) the long bothridial setae with a club-shaped head bearing spinules; (4) the presence of the anterior tubercles of enantiophyses B on the posterior prodorsum; (5) the pronounced notch anterior of the bothridium; (6) the pointed notogastral setae; (7) the presence of two pairs of epimeral foveolae.

Remarks. Neoeutegaeus phyllophorus is morphologically most similar to N. corniculatus , as detailed above. The Neoeutegaeus sp. recorded by Hunt et al. (1998) from rainforest litter at O’Reilly’s Rainforest Retreat, Lamington National Park, Queensland (28°14’S 153°08’E, coll. R. Kitching), and illustrated in Fig. 27 , is identified here as N. phyllophorus : it has well-developed epimeral foveolae, a character state that does not occur in other Neoeutegaeus species. Also, Neoeutegaeus sp. shares with N. phyllophorus similar dimensions, the invagination of the lateral lamella anterior of the bothridium, the long bothridial seta with a dilated head and short spines and the notogastral setae are the same size and shape.

Figures

FIGURE 26. Neoeutegaeus phyllophorus J. & P. Balogh, 1983a, adult (a) dorsal aspect; (b) ventral aspect. Scale bar = 100 μm.

FIGURE 27. Scanning electron micrographs of Neoeutegaeus sp. from O’Reilly’s Rainforest Retreat, Lamington National Park, Queensland (from Hunt et al., 1998b).