Plonaphacarus concavus, 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 : 8

Plonaphacarus concavus sp. nov.

( Figs. 10–18 )

Material examined. Holotype: adult (in alcohol, W-89-117), China: Hubei Province, Lichuan City (30°17'27.59"N, 108°56'10.95"E), Maoba, Xingdoushan Mt., from litter, 850M, 24 Jul., 1989, leg. Yun-Qi Cui.

Etymology. The new specific name “ concavus ” is from Latin, and refers to the concave anterodorsal part of notogaster.

Measurements: Holotype: Prodorsum: length 319, width 205, height 150, setae: ss 151, ro 30, in 25, le 27, ex 10, distance between setae: ro -ro 45, in -in 70, le -le 132; notogaster: length 710, width 420, height 390; setae: c1 150, c2 30, c3 24, c p 20, d1 35, d2 25, e1 25, e2 20, h1 25, h2 20, h3 20, ps1 40, ps2 25, ps3 25, ps4 15; distance between setae: c1-d1 242, d1-e1 205, e1-h1 190, h1-ps1 125; ventral region: an1 70, an2 70; genitoaggenital plate 148×145, anoadanal plate 195×140.

Colour grey-yellowish. Surface of body reticulate.

Prodorsum with one pair of strong dorsal carinae; lateral carinae moderately long, reaching sinus; dorsal and lateral region weakly visible; posterior furrows present; sensilli long, rough and setiform; other setae short, rough and spiniform, except exobothridial setae short and fine; interlamellar and lamellar setae semi-erect, rostral setae procumbent; comparative length: ss>ro>le> in>ex.

In lateral view, anterodorsal part of notogaster protrudent to form hook-like projection covering posterior part of prodorsum; frontal part of notogaster concave in dorsal view; 15 pairs of notogastral setae present, short, rough and spiniform, except setae c1 much longer and robust; setae c1-3 remote from anterior border, setae c2 more so than c1 and c3; vestigial setae f1 positioned anterior to setae h1; lyrifissures not observed.

Nine pairs of genital setae present, arranged in two rows with formula: 6(4+2): 3; one pair of aggenital setae present; three pairs adanal setae short, rough and spiniform; two pairs of long and robust anal setae present.

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’ (formora I)=3.75; setae d on femora I situated near distal end of article; setae a’’ on tarsi II curved distally; setae a’’ on tarsi I and setae ft’’ on tarsi II straight distally; setae s and pv’ on tarsi IV present; setae s on tarsi I absent and on tarsi 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 easily distinguished from other species of this genus by the combination of following characters: prodorsum with one pair of strong dorsal carinae; rostral setae procumbent; in lateral view, anterodorsal part of notogaster protrudent to form hook-like projection covering posterior part of prodorsum; frontal part of notogaster concave in dorsal view; 15 pairs of notogastral setae present, short, rough and spiniform, except setae c1 much longer and robust.

Figures

FIGURES 10 – 18. Plonaphacarus concavus sp. nov.: 10, lateral view of body (legs removed); 11, prodorsum, dorsal view; 12, anterodorsal part of notogaster, dorsal view; 13, left side of ventral plate; 14, mentum of infracapitulum; 15 – 18, trochanter, femur, genu and tibia: 15, leg I; 16, leg II; 17, leg III; 18, leg IV. Scale bars = 100 μm.