Novonothrus nothofagii, Colloff, Matthew J., 2011

Colloff, Matthew J., 2011, A review of the oribatid mite family Nothridae in Australia, with new species of Novonothrus and Trichonothrus from rain forest and their Gondwanan biogeographical affinities (Acari: Oribatida), Zootaxa 3005, pp. 1-44 : 18-20

Novonothrus nothofagii sp. nov.

(Figs. 10, 12g, 17d, 18c, 19a)

Dimensions. Holotype female length 782 μm, breadth 435 μm; paratype male length 732 μm, breadth 388 μm. Paratype females (n = 4) mean length 821 μm (range 808–843 μm), mean breadth 416 μm (range 394–455 μm);

Female. Prodorsum: Median light oval region 15 μm long 22 μm broad, Y-shaped ridge medial of lateral light oval regions (each 24 μm long, 17 μm broad) positioned anterior of lamellar setae. Rostral setae (ro) straight, smooth, spiniform, 24 μm long (Fig. 10a). Lamellar seta (le) 34 μm long, smooth, straight, spiniform, on squat tubercle positioned equidistantly between midline of prodorsum and lateral margin. Prodorsum expanded laterally in region posteriolateral of le. Interlamellar seta (in) 27 μm long, straight, smooth, spiniform, pointed, covered in bacilliform cerotegument. Bothridial rim rounded, without anterior ridge extending towards le. Exobothridial seta ex 1 not visible in dorsal view. Bothridial seta (bs) flagelliform, smooth, 188 μm long, apex reflexed. Prodorsum alveolate.

Notogaster: Ratio of length to breadth 1.42; notogaster barrel-shaped; margins convex, caudal margin transverse, slightly undulating (Fig. 10a). Notogastral cuticle with medium to large alveoli (4–10 μm diameter), occasionally paired, semi-circular ( Fig. 17 d), sparsely-distributed (5–12 μm apart). Setae of c -f series and p 3 slightly curved, pointed, smooth, broadened basally, 38–51 μm long. Distance between setae c 1 1.1 × that between c 1 and c 2; distance between setae c 1 0.9 × that between d 1; distance between d 2 1.6 × that between d 1; distance between e 1 1.3 × that between f 1. Setae of h series and p 1-2 barbed, covered in broad, phylliform cerotegument (Fig. 10c). Caudal margin rounded with slight crenellations. Faint longitudinal ridge on either side of notogaster extending from lateral of seta h 1 to lateral of seta c 2.

Subcapitulum: Mentum foveolate. Gena with four setae: a and m 1-3, a longer than others (Fig. 10b); coxal spine (e) present. With two adoral setae ( Fig. 12 g); curved, setiform, sub-equal in length.

Coxisternum: Epimeral plates I–III adjacent, plates IV separate along sternal line (Fig. 10b). Epimeral setal formula: 6-5-6-5. Epimeral setae smooth, setiform, 10–21 μm long. Setae on epimeral plates I and II positioned along medial part of plate; those of epimeral plate III and IV predominantly on posterior part of plate. Epimeral plates IV broadly triangular, with triangular posteriomedian spur adjacent to genital plate.

Anogenital Region: Each genital plate 133 μm long, 74 μm broad, divided transversely, with nine smooth setiform setae 17–26 μm long: six setae in median file (four on anterior part of plate) and three in lateral file (one on anterior part of plate; Fig. 10b). Pre-anal plate narrow, rounded laterally, 103 μm broad. Each anal plate 164 μm long, 41 μm broad, with two smooth, spiniform setae, 24–31 μm long; one on anterior, one on posterior part of plate. Adanal setae subequal in length and shape to anal setae. Ventral margin of notogaster posterior of anal plates entire, rounded.

Lateral View: Anterior prodorsal margin curved vertically; lateral expanded region extending as far as abjugal furrow (ab; Fig. 10d). Lamellar seta projecting almost as far as base of ro. Exobothridial seta ex 2 present as alveolus. Interbothridial region convex. Lyrifissure ia short (21 μm). Notogastral shield convex, elongated, flat between setae c 1 and f 1; ratio of notogastral height to length 0.53. Lateral notogastral ridge well-developed, coinciding with bases of lateral setae, curved ventrally in posterior part as far as base of seta h 3. Opening of opisthonotal gland positioned ventral of seta f 2, prominent, slit-like, surrounded by circular ridge of cuticle.

Legs: Pre-tarsus monodactylous. Tarsus I elongated, conical 178 μm long ( Fig. 19 a). Femur I 126 μm long in dorsal view; setae sparingly barbed ( Fig. 18 c); d slightly longer (40 μm) than others (26–30 μm). Setal formula of Leg I (solenidia in brackets): 7-5(1)-6(2)-27(3).

Material examined. Holotype female and paratype male, moss ( Dicranoloma billiardieri ), Nothofagus cunninghami forest, The Beeches, Lady Talbot Drive near Warburton, Yarra Ranges National Park, Victoria, 37°29'14"S 145°49'59"E, 800 m., coll G. Perdomo, May 2009. Five paratype females, FM (HD) 80-177 [SR 250], litter in Eucalyptus , Nothofagus cunninghami forest, Mount Donna Buang, 37°42'S 145°41'E, 1200 m., A. Newton & M. Thayer, 14.1.1980. Holotype and paratype from The Beeches deposited in the Australian National Insect Collection, CSIRO Ecosystem Sciences, Canberra. Two paratypes from Mount Donna Buang in Roy A. Norton collection, College of Environmental Science and Forestry, State University of New York, Syracuse. Other paratypes in Field Museum, Chicago.

Etymology. The specific name is from Nothofagus , alluding to its macrohabitat in Nothofagus cunninghami temperate rain forest.

FIGURE 10. Novonothrus nothofagii sp. nov., holotype female; a) dorsal; b) ventral; c) detail of seta h 1; d) lateral view.

Remarks. Novonothrus nothofagii sp. nov. differs from other members of the genus by the following combination of characters: 1) prodorsum with lateral expanded regions; 2) interlamellar setae smooth, spiniform, with bacilliform cerotegument; 3) notogastral cuticle with large, round, sparsely-distributed alveoli; occasionally paired, semi-circular; 4) notogastral setae of c -f series smooth, curved, thin; 5) notogastral setae h 1, h 2 and p 1 barbed, covered in phylliform cerotegument; 6) exobothridial seta very small, not visible in dorsal view; 7) caudal margin rounded with slight crenellations; 8) epimeral setation 6-5-6-5; 9) Tarsus I with 27 setae.

Novonothrus nothofagii is morphologically most similar to N. silvanus sp. nov. (cf. below) and N. barringtonensis , though is smaller than the latter species. All three species have smooth notogastral setae of the c -f series, and some of the h and p series are barbed: h 1, h 2 and p 1 in N. barringtonensis , h 1-3 and p 1 in N. nothofagii and N. silvanus . The epimeral setal formula is 6-5-6-5 or with minor variations. Novonothrus nothofagii differs from N. silvanus in having 27 rather than 38 setae on Tarsus I.

Figures

FIGURE 12. Novonothrus silvanus sp. nov., paratype female; a) subcapitulum; b) palp tarsus; c) adoral setae; d) N. barringtonensis sp. nov., paratype female, adoral setae; e) N. glabriseta sp. nov., paratype female, adoral setae; f) N. coronospinosus sp. nov., adoral setae; g) N. nothofagii sp. nov., adoral setae; h) N. glabriseta sp. nov., paratype female, detail of rostrum.

FIGURE 17. Detail of notogastral cuticle of Novonothrus spp.: a) N. barringtonensis sp. nov.; b) N. coronospinosus sp. nov.; c) N. glabriseta sp. nov.; d) N. nothofagii sp. nov.; e) N. silvanus sp. nov.; f) N. flagellatus Hammer, 1966.

FIGURE 18. Dorsal views of the right femur of Leg I of Novonothrus spp.: a) N. barringtonensis sp. nov.; b) N. coronospinosus sp. nov., c) N. nothofagii sp. nov., d) N. glabriseta sp. nov.; e) N. silvanus sp. nov.; f) N. flagellatus Hammer, 1966.

FIGURE 19. Tarsus I; a) Novonothrus nothofagii sp. nov., left, antiaxial aspect; b) N. glabriseta sp. nov., right, paraxial aspect; c) N. barringtonensis sp. nov., left, antiaxial aspect; d) N. flagellatus sp. nov., left, antiaxial aspect.