Euphthiracarus dilatatus, Liu, Dong, Wu, Donghui & Chen, Jun, 2011

Liu, Dong, Wu, Donghui & Chen, Jun, 2011, Species of Euphthiracarus (Acari: Oribatida: Euphthiracaridae) from China, Zootaxa 2752, pp. 45-61 : 50

Euphthiracarus dilatatus sp. nov.

( Figs. 11–14 )

Material examined. Holotype: adult (in alcohol, LD-07-51), China: Hainan Province, Changjiang Li Autonomous County, Bawangling National Nature Reserve (19º03'12"N, 109º06'49"E), Dongganxian, from litter under pine tree, 1040M, 3 Aug., 2007, leg. Dong Liu.

Etymology. The new specific name “ dilatatus ” is from Latin, and refers to the dilated head of sensilli.

Measurements. Holotype: Prodorsum: length 300, width 210, height 120, setae: ss 80, in 155, le 125, ro 80, ex 22.5, distance between setae: ro -ro 40, in -in 113, le -le 50, in -le 87, le -ro 93; notogaster: length 590, width 405, height 396; setae: c1 125, c2 108, c3 95, c p 97, d1 90, d2 85, e1 120, e2 100, h1 120, h2 110, h3 95, ps1 115, ps2 103, ps3 95; distance between setae: c1-d1 175, d1-e1 157, e1-h1 120, h1-ps1 107; ventral region: genitoaggenital plate 231×90, anoadanal plate 300×77.

Integument: Colour brown. Surface of body covered with dense foveolae, except region under lateral carinae smooth.

Prodorsum: Each side with two parallel lateral carinae, upper carina stronger than lower one; bothridial scale situated below bothridium, posterior median apodeme present; sensilli short with narrow pedicel and dilated head, truncate distally and covered with robust spines; interlamellar setae long, robust, erect, covered with spines in distal half; lamellar setae similar in shape to interlamellar setae, sparsely barbed in distal half; rostral setae smooth, semierect, bent and flagellate distally; exobothridial setae short and fine; comparative length: in>le> ss = ro>ex.

Notogaster: 14 pairs of notogastral setae, relatively short, similar in shape to lamellar setae, sparsely barbed in distal half; setae c1-3 remote from anterior border, setae c1 more so than setae c2 and c3; vestigial setae f1 not discerned; openings of opisthosomal glands and five pairs of lyrifissures present.

Venter: Genital plates with nine pairs of setae, g1-3 short and fine, located in progenital position, other setae thicker and slightly longer; two pairs of aggenital setae present, ag1 minute, ag2 thick and about twice as long as ag1; three pairs of anal and three pairs of adanal setae present, setae an1 and an2 smooth and flagellate at distal end, setae an3 and adanal setae shorter, robust and covered with small and sparse spines in distal half; lyrifissures iad situated between setae an3 and ad3.

Gnathosoma: Setae h of mentum longer than distance between them; palps three-segmented with setal formula: 2-2-8(1).

Legs: Chaetotaxy of legs (without tarsi): I: 1-3-5(2)-5(1); II: 1-4-4(1)-5(1), III: 2-2-2(1)-2(1), IV: 2-1-1(1)- 2(1); all legs heterotridactylous.

Distribution. Known only from type locality.

Remarks. This new species is similar to E. takahashii Aoki, 1980 in having similar shape of sensilli, but differs from the latter by following characters: setae c1 not distinctly longer than setae d1, less twice as long as setae d1; posterior four genital setae not much longer than anterior ones; sensilli and rostral setae equal in length; notogastral setae sparsely barbed in distal half. This new species is also similar to E. cribarius ( Berlese, 1904) , but can be easily distinguished from the latter by following characters: surface of body covered with dense foveolae; sensilli short with narrow pedicel and dilated head covered with robust spines.

Figures

FIGURES 11 – 14. Euphthiracarus dilatatus sp. nov.: 11, lateral view of body (legs removed); 12, prodorsum, dorsal view; 13, sensillus; 14, ventral plates. Scale bars: 11 – 12, 14 = 100 μm; 13 = 50 μm.