Neseutegaeus Woolley, 1965

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 : 29

Neseutegaeus Woolley, 1965

Neseutegaeus Woolley, 1965, p. 307 .

Neseutegaeus Woolley, 1965 : Luxton, 1988a, p. 77.

Type species: Neseutegaeus spinatus Woolley, 1965 .

Diagnosis. The following diagnosis is modified from those of Woolley (1965) and Luxton (1988a): small to medium-sized oribatid mites (330–550 μm); rostrum rounded; lamellar cusps about one-third length of lamellae, rounded or obtuse apically, not projecting markedly beyond rostrum, with long, narrow, incurved medial tooth, lamellae separated from each other and translamella complete, incomplete or absent; lamellar seta emerging dorsally from lateral margin of lamellar cusp. Interlamellar setae short, not overlapping; bothridial setae long, club-shaped apically. Posterior margin of bothridium with anterior condyles of enantiophyses H. Humeral process long, slim, waisted basally, originating on anterolateral margin of notogaster, reaching to point half-way along length of lamella; anterolateral margin of notogaster conspicuously incised at base of humeral process, but lacking Vshaped or rounded projection. Notogaster U-shaped; with eight pairs of thick, short setae, no longer than distance between them, those of l series in centrodorsal position; h series centrodorsal or sub-marginal; setae of l and h series differing in shape in some species: those of l series sharp, spiniform, those of h series blunt, club-shaped; setae of p series minute. Pedotectum I (pd I) sub-rectangular in ventral view, pd II rectangular, discidium triangular, pointed. Margins of epimeral plates IV incomplete. Five or six pairs of genital setae; three pairs of adanal setae. Perigenital carina and enantiophysis E4 absent. Chelicerae chelate-dentate, of normal proportions. Pre-anal organ oval.

Remarks. Neseutegaeus spinatus Woolley, 1965 from Alex Knob Track, Westland, New Zealand was given a supplementary description by Hammer (1966, p. 72) based on non-type material from Fox Glacier and Milford. Woolley (1965) stated there are six pairs of genital setae, but Hammer reported five, present as alveoli: the setae could not be seen. Additional character states observed by Hammer (1966, Plate 32, Fig. 98c) of relevance to the generic definition include the lozenge-shaped anal plates; the circumpedal carinae (cc); the epimeral setal formula 3-1-3-2; the oval pre-anal organ and the morphology of the epimeral plates, with plates III smaller than others; lyrifissures iad in the para-anal position but not close to the anal plates and pedotectum I well-developed with margins semi-rectangular in outline.

Neseutegaeus denticulatus P. Balogh (1988) was described from Sri Lanka. But the species is not a Neseutegaeus as the lamellae are fused anteriorly, not free and with a medially-directed tooth as is characteristic for the genus. Pedotecta I and II are large, broad and pointed which, if confirmed, is unique within Eutegaeoidea . Coxisternal structures are uncertain from the description, including the morphology of the discidium, epimeral setal formula and the presence of enantiophyses E4 and perigenital carinae (P. Balogh, 1988, Figs. 16-18 therein). The species cannot be assigned to an existing genus within Eutegaeoidea , but requires re-description before consideration whether the establishment of a new genus is warranted.

The redefinition of Neseutegaeus above includes the four species described by Hammer (1966) ( N. angustus , N. consimilis , N. distendus and N. latus ) and N. spinatus , all from New Zealand. Neseutegaeus monteithi J. and P. Balogh, 1983b was described from Australia, but lacks the characteristic, thin elongated incurved tooth emerging from the centre of the apically transverse or obtuse lamellar cusp of the other species. Also, the interlamellar setae are long and recurved; the notogastral setae are not spiniform or club-shaped; there is a conspicuous pair of rounded projections at the base of the humeral process and the base of the process is not sharply incised. Neseutegaeus monteithi has a lamellar cusp with a well-developed apical tooth and the lamellar setae emerge sub-apically from the dorsal surface of the lateral margin of the cusp and very long, recurved interlamellar setae, recurved setae of the l series and a thin, narrow humeral process, typical of Atalotegaeus . On the basis of these character states, N. monteithi is recombined as Atalotegaeus monteithi (J. and P. Balogh, 1983b) comb. nov. and is redescribed below.

Figures

FIGURE 16. Atalotegaeus mensarosi (J. & P. Balogh, 1983), tritonymph, (a) dorsal aspect with larval and nymphal scalps; (b) ventral aspect. Scale bar = 200 μm.

FIGURE 17. Atalotegaeus monteithi (J. & P. Balogh, 1983a) comb. nov., adult (a) dorsal aspect; (b) ventral aspect. Scale bar = 200 μm.

FIGURE 18. Humerotegaeus carinatus gen. et sp. nov., adult (a) dorsal aspect; (b) ventral aspect. Scale bar = 200 μm.