Neseutegaeus wardi, 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 : 30-31

Neseutegaeus wardi sp. nov.

( Fig. 12 )

Dimensions. Holotype male length 306 μm, breadth 195 μm. Paratype females (n = 5): mean length 333 μm (range 331–337); mean breadth 222 μm (range 217–226). Paratype males (n = 4): mean length 313 μm (range 305–323); mean breadth 204 μm (range 195–212). Ratio of prodorsum to total length: 0.41 (holotype).

Description of adult. Prodorsum: rostrum rounded; rostral setae (ro) short, curved, smooth, visible in dorsal aspect. Lamellae broad, extending beyond lateral margin of prodorsum, separated medially, lateral margins convex, without translamella ( Fig. 12a ). Lamellar seta (le) long, smooth, incurved, emerging from apex of lamellar cusp just anterior of long, thin, medially-directed lamellar tooth. Interlamellar seta (in) thin, relatively short, flagelliform with thick cylinder of cerotegument basally, emerging from lateral margin of inverted V-shaped prodorsal ridge. Bothridia prominent, overlapping laterally with inner margins of humeral processes, openings angled anterolaterally, anterior margin with squat tubercle, posterior margin with anterior condyle of enantiophysis H in form of V-shaped projection. Bothridial seta long, recurved, apex slightly expanded with fine spines. Curved ridge with wavy margin on prodorsum between bothridia.

Notogaster: ratio of length to breadth: 0.89; notogaster U-shaped, convex. Humeral processes narrow, with few small scattered tubercles, lateral margin convex, medial margin concave, with V-shaped basal indentation laterally and slight notch medially, apex pointed extending anteriorly to point level with middle of lamella ( Fig. 14a ). With eight pairs of notogastral setae: l, h 2 and h 3 and p series present, setae of l and h series flat, leaf-shaped, slightly curved, with pectinate margins ( Fig. 12c ), in centrodorsal position; p series short, smooth, curved, visible in dorsal view.

Ventral aspect: subcapitulum acute apically; subcapitular setae short, smooth, seta a twice as long as m and h ( Fig. 12b ). Chelicerae chelate-dentate, of normal proportions. Tutorium not visible in ventral aspect. Epimeral plates I-III discrete, separated in midline, sub-rectangular to sub-triangular, plates I with a small ovoid depression between them, plates IV lacking posterior margin; epimeral setation 2-1-3-2; setae 4b slightly longer than others. Pedotectum I (pd I) sub-rectangular in lateral outline; pd II small, blunt, sub-rectangular, not projecting beyond lateral margin of pd I; discidium well-developed, blunt, pointed. Ventral plate U-shaped, broader than long, with cluster of short tubercles near circumpedal carina. Genital and anal plates separated by distance about same as length of genital plates; genital plates 35 µm long, with six pairs of setae aligned longitudinally, g 1 longer than others, distance between g 5 and g 6 markedly greater than between g 4 and g 5; lyrifissure iad in para-anal position, close to margin of anal plate. Anal plates lozenge-shaped, 49 µm long; setae of the ad series very short. Pre-anal organ (po) oval.

Type designation, material examined and locality data. Holotype male, ANIC accession no. 53-1044, ANIC 578 , moss forest, Mount Panie [Mont Panié], New Caledonia, 20°34'S, 164°46'E, 750 m., coll. P.S. Ward, 14.ii.1977 . Paratypes: seven females, five males, ANIC accession no. 53-1045, ANIC 580 , litter, rainforest, Mount Koghis [Mont Koghi], New Caledonia, 23°11'S, 166°31'E, 749 m . [summit], coll. P.S. Ward, 18.ii.1977.

Etymology. This species is named in honour of its collector, Professor Philip S. Ward, Department of Entomology and Nematology, University of California, Davis.

Diagnosis. Neseutegaeus wardi can be distinguished from the other species in the genus by the following combination of characters: (1) the prominent bothridia, extending well beyond the lateral margin of the prodorsum; (2) the curved ridge between the bothridia; (3) the scattered tubercles on the humeral process; (4) the flattened, pectinate setae of the l and h series; (5) the epimeral setal formula 2-1-3-2; (6) epimeres I with a small ovoid depression between them; (7) the marked gap between genital setae g 5 and g 6 compared with the other genital setae; (8) the cluster of small tubercles near the circumpedal carina.

Remarks. Neseutegaeus wardi is not particularly morphologically similar to other species of Neseutegaeus . The setae of the l and h series are leaf-like, pectinate, and in the centrodorsal position, like those of N. spinatus Woolley, 1965 (cf. Hammer, 1966, Fig. 98b therein), though the spines on the setae of N. wardi are much longer. Unlike N. wardi , N. spinatus has heavily striated lamellae, a partial translamella and the interlamellar setae are setiform, not flagelliform. Neseutegaeus wardi differs from N. consimilis and N. distentus in that their notogastral setae are thin, curved and smooth. The new species differs from N. angustus and N. latus in that these species have notogastral setae of the l series that differ in morphology from the h series. Neseutegaeus wardi is the first species in the genus to be recorded outside New Zealand.

Figures

FIGURE 12. Neseutegaeus wardi sp. nov., adult (a) dorsal aspect; (b) ventral aspect. Scale bar = 100 μm.

FIGURE 14. Atalotegaeus deficiens sp. nov., adult (a) dorsal aspect; (b) ventral aspect. Scale bar = 200 μm.