Arphthicarus spiniformis, Liu & Wu & Chen, 2014

Liu, Dong, Wu, Donghui & Chen, Jun, 2014, First record of the genus Arphthicarus Niedbała (Acari: Oribatida: Phthiracaridae) from China, with descriptions of two new species, Journal of Natural History (J. Nat. Hist.) 48 (35 - 36), pp. 2199-2206 : 2203-2205

Arphthicarus spiniformis sp. nov.

( Figure 2 )

Diagnosis

Surface of body foveolate; lateral carinae and median carina absent; sigillar fields weakly visible; posterior furrows present; sensilla with long and narrow pedicel and rounded head; interlamellar and notogastral setae thick and semi-erect, covered with small spines in distal half; lamellar setae minute; rostral setae spiniform, short, smooth and semi-erect; exobothridial setae short and fine; ss> in> ro>le> ex; vestigial setae f 1 posterior to setae h 1; two pairs of lyrifissures ia and im present; h <h–h; setae g 6 situated slightly anteriolateral to g 4; setae ad 2 situated between setae an 1 and an 2, and far away from setae an 1; setae ad 3 smooth; ad 2> ad 1> an 1 = an 2> ad 3; setae d on femora I situated near distal end of article.

Material examined

Holotype: adult ( ZMCAS, in alcohol, N–17), China: Guangxi Province, Xing’ an County, Maoershan Mts. (25°52 ʹ 51.56 ʺ N, 110°29 ʹ 39.54 ʺ E), from moss, 1200 m, 14 July 1985, leg. Yun-Qi Cui . Paratypes: two adults ( NIGA, in alcohol), China: Guangxi Province, Lipu County (24°29 ʹ 16.23 ʺ N, 110°23 ʹ 42.77 ʺ E), from litter, 22 October 2012, leg. Yong-Ming Wu.

Description

Measurements. Holotype: Prodorsum: length 187, width 135, height 82, setae: ss 45, ro 22, le 12, in 43, ex 4; distance between setae: ro–ro 16, in–in 53, le–le 86; notogaster: length 330, width 220, height 200; setae: c 1 46, c 2 43, c 3 43, c p 45, d 1 40, d 2 35, e 1 35, e 2 40, h 1 36, h 2 45, h 3 35, ps 1 40, ps 2 45, ps 3 41, ps 4 40; distance between setae: c 1 – d 1 75, d 1 – e 1 105, e 1 – h 1 77, h 1 – ps 1 60; ventral region: ad 1 50, ad 2 56, ad 3 30, an 1 31, an 2 31; genitoaggenital plate 136 × 90, anoadanal plate 151 × 120. Paratypes: Prodorsum: length 175–180, width 130–135, height 80–85; notogaster: length 320–325, width 205–215, height 190–195.

Integument. Colour yellowish. Surface of body foveolate.

Prodorsum ( Figure 2A–C ). Lateral carinae and median carina absent; sigillar fields weakly visible; posterior furrows present; sensilla (ss) with long and narrow pedicel and rounded head; interlamellar setae (in) thick, semi-erect and pointed distally, covered with small spines in distal half; lamellar setae (le) minute and smooth; rostral setae (ro) spiniform, short, smooth and semi-erect, thicker than lamellar setae; exobothridial setae (ex) short and fine; comparative length: ss> in> ro>le> ex.

Notogaster ( Figure 2A ). Fifteen pairs of setae present, short (c 1 <c 1 – d 1), similar shape to interlamellar setae, setae c 1 longest, setae d 2, e 2 and h 3 shortest; setae c 1–3 remote from anterior border, setae c 2 more remote than c 1 and c 3; vestigial setae f 1 posterior to setae h 1; two pairs of lyrifissures ia and im present.

Ventral region ( Figure 2D, E ). Setae h of mentum shorter than distance between them. Nine pairs of genital setae (g) present, arranged with formula: 6(4 + 2): 3. Anoadanal plates each with five setae (ad and an), pointed distally, setae ad 1 and ad 2 rough, nearly straight, longer and thicker than other setae, setae ad 3 and anal setae slightly thinner and smooth; comparative length: ad 2> ad 1> an 1 = an 2> ad 3.

Legs ( Figure 2F–I ). Setal counts for leg segments (without tarsi): I: 1–4–2(2)–5(1); II: 1–3–2(1)–3(1), III: 2–2–1(1)–2(1), IV: 2–2–1–2(1); setae d on femora I situated near distal end of article; setae a” on tarsi I and setae ft” on tarsi II curved distally; setae a” on tarsi II curved distally; setae s and pv’ on tarsi IV present; setae s on tarsi I and II absent; setae d on tibiae IV short.

Etymology

The new specific name ‘ spiniformis ’ is from Latin, and refers to the shape of rostral setae.

Remarks

This new species is similar to Arphthicarus evexus Niedbała, 2000 from Vietnam in the presence of posterior furrows on prodorsum, two pairs of lyrifissures present, vestigial setae f 1 posterior to setae h 1, similar shape of sensilla, short and fine lamellar setae, h <h–h, but can be easily distinguished from the latter species by following characters: in A.spiniformis sp. nov., lateral carinae absent; interlamellar setae much shorter (in 43), ss> in; rostral setae shorter (ro 22) and semi-erect; setae g 6 situated slightly anteriolateral to g 4; setae ad 2 shorter and straight, situated between setae an 1 and an 2, and far away from setae an 1; setae ad 3 smooth. In A.evexus lateral carinae distinct; interlamellar setae much longer (in 75.9), in> ss; rostral setae longer (ro 37.9), lying parallel to surface of prodorsum; setae g 6 situated at the level between g 4 and g 5, and closer to g 5; setae ad 2 longer and hooked, situated posteriolateral to setae an 1, and very close to setae an 1; setae ad 3 covered with small setae.

Figures

Figure 2. Arphthicarus spiniformis sp. nov. (A) Lateral view of body (legs removed); (B) prodorsum, dorsal view; (C) sensillum, dorsal view; (D) right side of ventral plate; (E) mentum of infracapitulum; (F–I) trochanter, femur, genu and tibia: (F) leg I; (G) leg II; (H) leg III; (I) leg IV. Scale bars: 50 μm.