Austrophthiracarus taranaki, Liu & Zhang, 2018

Liu, Dong & Zhang, Zhi-Qiang, 2018, New Zealand Austrophthiracarus (Acari, Oribatida, Steganacaridae): two new species from the North Island, Zootaxa 4500 (3), pp. 443-450 : 444-445

Austrophthiracarus taranaki sp. nov.

( Figures 1A–H )

Diagnosis. Entire surface of idiosoma finely punctate; one pair of prodorsal lateral carinae present; median sigillar fields long and bifurcate distally; sensilli short narrow fusiform with pointed head; other prodorsal setae short and fine, nearly similar in length; 16 pairs of notogastral setae present, all stout and sparsely barbed; vestigial setae f 1 positioned posterior to setae h 1; two pairs of lyrifissures ia and im present; h>h–h; formula of genital setae: 6(4+2):3; setae ad 1, ad 2 and anal setae stout and sparsely barbed, setae ad 3 rough and thinnest.

Description. Measurements. Holotype: Prodorsum: length 315, width 230, height 110, setae: ss 45, ro 30, in 22, le 25, ex 15; notogaster: length 620, width 445, height 460; setae: c 1 130, c 2 125, c 3 110, cp 110, d 1 115, e 1 115, h 1 125, h 3 90, ps 1 125, ps 4 65; ad 1 60, ad 2 55, ad 3 38, an 1 105, an 2 95; genito-aggenital plate 110×165, ano-adanal plate 95×245. Paratypes: Prodorsum: length 305–310, width 225, height 100–103; notogaster: length 600–615, width 430–440, height 450–455.

Integument. Colour dark brown. Entire surface finely punctate.

Prodorsum ( Figs 1A–B ). Median crista, posterior furrows absent; one pair of lateral carinae present, not reaching sinus; sigillar fields distinct, median field long, bifurcate distally, lateral fields shorter; sensilli (ss) short narrow fusiform with pointed head; other prodorsal setae (in, le, ro and ex) short and fine, nearly similar in length; comparative length: ss> ro> le> in> ex, in–in / ro–ro≈ 2.32.

Notogaster ( Fig. 1A ). 16 pairs of notogastral setae present, medium in length (c 1 / c 1 – d 1 ≈0.77), stout, erect, and sparsely barbed in distal half; additional setae located in ps rows; setae c 1 and c 2 further away from anterior border than setae c 3 vestigial setae f 1 positioned posterior to setae h 1; two pairs of lyrifissures ia and im present.

Gnathosoma ( Figs 1D–F ). Subcapitulum typical of family ( Fig. 1D ); setae h, m and a simple and smooth; setae h longer than distance between them; adoral seta or 1 apparently flat with barbs; or 2–3 simple and smooth; palp ( Fig. 1E ) 4-segmented, with femur and genu fused; palpal setation: 0-2-2-7(1); supracoxal seta simple and smooth; chelicera ( Fig. 1F ) typical of family.

Ano-genital region ( Figs 1A, C ). Nine pairs of genital setae (g) arranged with formula: 6(4+2):3; ano-adanal plates each with five setae (ad, an), setae ad 1 and ad 2 stout and sparsely barbed, setae ad 3 rough and thinnest; anal setae sparsely barbed, straight and longer; comparative length: an 1> an 2> ad 1> ad 2> ad 3.

Legs ( Figs 1G–H ). Setal counts for leg segments: I: 1-4-2(2)-4(1)-19(3); II: 1-3-2(1)-3(1)-12(2), III: 2-2-1(1)- 2(1)-10, IV: 2-1-1-2(1)-10; setae d on femora I inserted located near distal ends of articles; setae a’’ on tarsi I and setae ft’’ on tarsi II straight; setae a’’ on tarsi II curved distally; setae s and pv’ on tarsi IV present; setae s on tarsi I and II present.

Material examined. Holotype: adult ( NZAC, in alcohol, 77/33), New Zealand: TK, Wilkies Pools , Dawson Falls area, Egmont National Park, 1170 m a.s.l., from moss, 21 Feb. 1977, leg. B. M. May. Paratypes: two adults ( NIGA, in alcohol, 77/133), same data as holotype .

Type deposition. Holotype specimen is deposited in NZAC . Paratypes are deposited in NIGA .

Etymology. Named after Mt. Taranaki and used as a noun in apposition.

Remarks. This new species is similar to Austrophthiracarus filiformis Liu & Chen, 2014 in having one pair of prodorsal lateral carinae present, prodorsal setae short and 16 pairs of fine notogastral setae present, vestigial setae f 1 positioned posterior to setae h 1, formula of genital setae: 6(4+2):3, ano-adanal plates with five setae, setae d on femora I inserted near distal ends of articles, but can be differentiated by: 1) sensilli short narrow fusiform with pointed head (versus setiform, long and narrow in A. filiformis ); 2) median sigillar fields bifurcate distally (versus connected but not bifurcate); 3) additional setae located in ps rows (versus in h rows); 4) two pairs of notogastral lyrifissures present (versus four pairs); 5) setae g 6–9 short, not longer than distance between them (versus longer); 6) adanal setae shorter than anal setae (versus longer than anal setae).

Compared with Austrophthiracarus vestigius Liu & Wu, 2016 , this new species is similar by short lamellar and rostral setae, and 16 pairs of notogastral setae present, but differs by the following characters: 1) one pair of prodorsal lateral carinae present (versus absent in A. vestigius ); 2) sensilli with pointed end (versus rounded end); 3) interlamellar and exobothridial not vestigial (versus vestigial); 4) setae cp situated at level of setae h 2 (versus much lower, nearly at level of setae h 3); 5) two pairs of notogastral lyrifissures present (versus four pairs); 6) formula of genital setae: 6(4+2):3 (versus 9(4+5):0); 7) ano-adanal plates with five setae (versus six setae); 8) setae d on femora I inserted near distal ends of articles (versus remote).

Figures

FIGURE 1. Austrophthiracarus taranaki sp. nov.: A, lateral view of body (legs removed); B, prodorsum, dorsal view; C, left side of ventral plate; D, subcapitulum, palpi removed; E, palp, antiaxial view; F, chelicera, antiaxial view; G, tibia IV; H, femur I. Scale bars: A–C=100 µm; D–H=50 µm.