Plonaphacarus hainanensis, Liu, Dong, Wu, Donghui & Chen, Jun, 2011

Liu, Dong, Wu, Donghui & Chen, Jun, 2011, Review of Plonaphacarus (Acari: Oribatida: Steganacaridae), with descriptions of eight new species from China, Zootaxa 2739, pp. 1-26 : 13

Plonaphacarus hainanensis sp. nov.

( Figs. 34–40 )

Material examined. Holotype: adult (in alcohol, LD-07-51), China: Hainan Province, Changjiang Li Autonomous County, Bawangling National Nature Reserve (19º07'0.5"N, 109º05'6.3"E), from litter under pine forest, 1040M, 3 Aug., 2007, leg. Dong Liu. Paratype: one adult (in alcohol, LD-07-51), same data as holotype.

Etymology. The new specific name “ hainanensis ” refers to the locality of Hainan.

Measurements: Holotype: Prodorsum: length 230, width 160, height 106, setae: ss 80, ro 35, in 85, le 15, ex 10, distance between setae: ro -ro 25, in -in 90, le -le 105; notogaster: length 508, width 310, height 279; setae: c1 45, c2 45, c3 35, c p 30, d1 40, d2 25, e1 30, e2 25, h1 35, h2 35, h3 25, ps1 35, ps2 35, ps3 30, ps4 25; distance between setae: c1- d1 170, d1-e1 150, e1-h1 120, h1-ps1 85; ventral region: ad1 35, ad2 65, ad3 15, an1 35, an2 35; genitoaggenital plate 103×110, anoadanal plate 140×75. Paratype: Prodorsum: length 225, width 160, height 100; notogaster: length 465, width 285, height 270.

Colour brown. Surface of body covered with distinct concavities..

Prodorsum with one strong dorsal carina, like a crown in lateral view; lateral carina and posterior furrow absent; dorsal and lateral region invisible; sensilli long with narrow pedicel and sickle-like head, covered with small spines unilaterally; interlamellar setae long, robust, curved backward and densely covered with small spines; rostral setae spiniform, rough and procumbent; lamellar and exobothridial setae short and fine; comparative length: in>ss> ro>le> ex.

Anterodorsal part of notogaster protrudent to form a hook-like projection covering posterior part of prodorsum; 15 pairs of short notogastral setae present, setae h3, ps3 and ps4 rough, thin and spiniform, other setae robust, bacilliform and densely barbed in distal half; setae c1 and c3 close to anterior border, setae c2 more remote than them; vestigial setae f1 positioned posterior to setae h1; two pairs of lyrifissures ia and im present.

Nine pairs of genital setae present, arranged in two rows with formula: 6(4+2): 3; one pair of aggenital setae present; anoadanal plates each with five well-developed setae, setae ad2 longest, setae ad3 shortest, shorter than anal setae.

Setae h of mentum longer than distance between them; chaetotaxy of legs (without tarsi): I: 1-4-2(2)-5(1); II: 1-3-2(1)-3(1), III: 2-2-1(1)-2(1), IV: 2-1-1-2(1); v’’ / v’ (femora I)=2.33; setae d on femora I situated near distal end of article; setae a’’ on tarsi I and II and setae ft’’ on tarsi II straight distally; setae s and pv’ on tarsi IV and setae s on tarsi I and II present; setae l’ on genua IV reduced; setae d on tibiae IV long, independent of solenidions; all legs monodactylous.

Distribution. Known only from type locality.

Remark. This new species is similar to P. concavus sp. nov., but differs by the following characters: In P. concavus , prodorsum with lateral carinae and posterior furrows; sensilli setiform; interlamellar setae short and spiniform; frontal part of notogaster concave in dorsal view; notogastral setae short, rough and spiniform, except setae c1 much longer and robust; adanal setae spiniform, much shorter than anal setae. In P. hainanensis , prodorsum without lateral carinae and posterior furrows; sensilli with sickle-like head, covered with small spines unilaterally; interlamellar setae long, robust, curved backward and densely covered with small spines; frontal part of notogaster normal in dorsal view; notogastral setae robust, bacilliform and densely barbed in distal half, except setae h3, ps3 and ps4 rough, thin and spiniform; adanal setae well-developed.

Figures

FIGURES 34 – 40. Plonaphacarus hainanensis sp. nov.: 34, lateral view of body (legs removed); 35, prodorsum, dorsal view; 36, left side of ventral plate; 37 – 40, trochanter, femur, genu and tibia: 37, leg I; 38, leg II; 39, leg III; 40, leg IV. Scale bars = 100 μm.