Hoplophthiracarus sidorchukae, Liu & Zhang, 2019

Liu, Dong & Zhang, Zhi-Qiang, 2019, Hoplophthiracarus sidorchukae sp. nov. (Acari, Oribatida, Phthiracaridae) from the North Island, New Zealand, Zootaxa 4647 (1), pp. 226-230 : 227-229

Hoplophthiracarus sidorchukae sp. nov.

( Figures 1 A–F)

Diagnosis. Entire surface of idiosoma finely punctate; one pair of short prodorsal lateral carinae present; sensilli medium size with swollen and rough head; interlamellar setae stout and erect; lamellar setae short and thin; rostral setae semi-erect; in> ss> ro> ex> le; one additional notogastral setae located in ps rows; vestigial setae f 1 positioned posterior to setae h 1; four pairs of notogastral lyrifissures present; setae h of mentum vestigial; formula of genital setae 7(4+3):2; ano-adanal plates with five pairs of setae, setae ad 2 longest and hooked distally, setae ad 3 similar in shape to genital setae; setae d on femora I curved distally and situated remote from distal ends of segments.

Description. Measurements. Holotype: Prodorsum: length 275, width 125, height 103, setae: ss 25, ro 23, in 42, le 15, ex 20; notogaster: length 535, width 352, height 335; setae: c 1 60, d 1 58, e 1 55, h 1 60, ps 1 62; ad 1 45, ad 2 75, ad 3 15, an 1 32, an 2 32; genito-aggenital plate 20 5×14 2, ano-adanal plate 26 5×160. Paratype: Prodorsum: length 290, width 132, height 106; notogaster: length 550, width 365, height 345.

Integument. Colour brown. Entire surface finely punctate.

Prodorsum ( Figs 1 A–B). Median crista, posterior furrows absent; one pair of short lateral carinae present, not reaching sinus; sigillar fields distinct, median field long, lateral fields shorter; sensilli (ss) medium size with swollen and rough head; interlamellar setae (in) stout and erect; lamellar setae (le) thin and shortest; rostral setae (ro) spiniform and semi-erect, thicker than lamellar setae; exobothridial setae (ex) short and fine; all prodorsal setae rough, except lamellar and exobothridial setae smooth; comparative length: in> ss> ro> ex> le, in–in / ro–ro≈ 4.25, in–in / in–le≈ 3.62.

Notogaster ( Fig. 1A ). 16 pairs of notogastral setae present, medium in length (c 1 / c 1 – d 1 ≈0.55), stout, erect and rough; additional setae located in ps rows; setae c 1 and c 3 slightly near anterior margin, setae c 2 remote from margin; vestigial setae f 1 and f 2 present, setae f 1 positioned posterior to setae h 1; four pairs of notogastral lyrifissures ia, im, ip and ips present.

Ventral region ( Figs 1A , C–D). Setae h of mentum vestigial. Nine pairs of genital setae (g) arranged with formula: 7(4+3):2; setae g 6 situated between level of setae g 4 – g 5, and closer to setae g 5; distance between g 7 and g 8 and between g 4 and g 5 long; ano-adanal plates each with five rough setae (ad, an), setae ad 2 longest and hooked distally; setae ad 3 shortest and thinnest, similar in shape to genital setae; comparative length: ad 2> ad 1> an 1 = an 2> ad 3.

Legs ( Figs 1 E–F). Setal counts for leg segments: I: 1-4-2(2)-5(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 curved distally, located at level of setae v’’, distinctly remote from distal ends of segments; setae a’’ on tarsi I and II and setae ft’’ 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, 84/33), New Zealand: CL, Mercury Islands , Middle Island, from litter, 19 Feb. 1984, leg. G. Hall. Paratype: one adult ( NIGA, in alcohol, 84/33), same data as holotype .

Type deposition. Holotype specimen is deposited in NZAC and the paratype is deposited in NIGA.

Etymology. The species is named in memory of Dr. Ekaterina A. Sidorchuk (09.07.1981 – 20.01.2019), an outstanding acarologist from Paleontological Institute, Russian Academy of Sciences, for her significant contributions to Acarology (see Rasnitsyn 2019 for details of her research and contributions).

Remarks. This new species is distinctly different from congeneric species by having 16 pairs of rough and stout notogastral setae, finely punctate surface, prodorsum without median crista and posterior furrows, interlamellar setae less than three times longer than lamellar setae, and setae h of mentum vestigial.

Compared with Hoplophthiracarus bisulcus Niedbała, 1993 , the new species is morphologically similar in having finely punctate surface of prodorsum, median crista and posterior furrows absent, similar shape of rostral setae, similar length of interlamellar and lamellar setae, two pairs of vestigial setae f 1 and f 2 present, and setae f 1 positioned posterior to setae h 1, but can be differed by (1) surface of notogaster finely punctate (versus comma-like sculptured in H. bisulcus ); (2) one pair of short prodorsal lateral carinae present (versus absent); (3) sensilli medium size (ss> ro) with narrow stalk and swollen head (versus ss <ro and lanceolate); (4) interlamellar setae stout, lamellar setae thin (versus all flagellate); (5) in> ss> ro> ex> le (versus in> ro> le> ss> ex); (6) 16 pairs of notogastral setae, stout and medium size (versus 15 pairs, flagellate and longer); (7) ad 3 setae similar in shape to genital setae (versus much longer and thicker than genital setae); (8) setae h of mentum vestigial (versus short); (9) setae d on femora I curved distally, located at level of setae v’’ (versus forked distally, located anterior to level of setae l”).

Figures

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