Suctobelbella (Ussuribata) wiryeca, Bayartogtokh & Bae, 2024

Bayartogtokh, Badamdorj & Bae, Yang-Seop, 2024, New findings of oribatid mites of the genus Suctobelbella (Acari: Oribatida: Suctobelbidae) from Korea, Zootaxa 5556 (1), pp. 226-241 : 236-238

Suctobelbella (Ussuribata) wiryeca sp nov.

( Figures 7 , 8 )

Diagnosis. Body length 189 μm, width of notogaster 113 μm. Rostrum rounded centrally, with one large and 2–3 small teeth laterally. Tectopedial field large, narrowed anteriorly, but not fused; median prodorsal tubercle irregular oval. Lamellar and interlamellar seta thin, smooth; bothridial seta clavate, with long stalk and oval, smooth head. Interbothridial tubercle irregular oval; postbothridial tubercle rounded. Notogaster almost round, very slightly longer than wide; medial tubercle slightly smaller than lateral tubercle; notogastral setae c, l - and h -series very long, strongly barbed; setae p 1 and p 2 small, thin, smooth. Sejugal apodeme and apo.2 strongly developed, without medial cavity; epimeral setae medium long, genital setae g 2 – g 6 short, other anogenital setae fairly long, all thin, smooth.

Measurements. Body length 189 μm, width of notogaster 113 μm, length of notogaster 126 μm.

Integument. Body colour yellowish brown, prodorsum dorsally and laterally with numerous tubercles; notogaster and posterior part of ventral plate covered by granular cerotegument.

Prodorsum ( Figs 7A, C , 8A, C, D ). Rostrum rounded centrally, with one large and 2–3 small teeth laterally. Tectopedial field large, elongate irregular oval, narrowed anteriorly, but not fused; median prodorsal tubercle irregular oval, with small posterior projection. Rostral seta inserted laterally, geniculate, ciliate unilaterally in medial part. Lamellar seta medium long; interlamellar seta short, both setae thin, smooth; exobothridial seta not evident. Bothridial seta clavate, with long stalk and oval, smooth head. Interbothridial tubercle irregular elongate oval, narrowed anteriorly, but rounded posteriorly; postbothridial tubercle rounded.

Notogaster ( Figs 7A , 8A ). Almost round, very slightly longer than wide, anterior margin slightly rounded. Medial tubercle slightly smaller than lateral humeral tubercle, opposite to interbothridial and postbothridial tubercles, respectively. Lenticulus oval, with distinct anterior and lateral borders, situated at level slightly anterior to seta la. Nine pairs of notogastral setae: c, l - and h -series very long, strongly barbed; p 1 and p 2 small, thin, smooth. Lyrifissures and opisthonotal gland opening not evident.

Gnathosoma ( Figs 7B , 8B ). Subcapitulum, palp and chelicera typical for family. Subcapitulum longer than wide; subcapitular seta h distinctly longer than a and m, all setae setiform, smooth.

Epimeral region ( Figs 7B , 8B ). Apodemes apo.sj and apo.2 well developed, without cavity medially. With typical epimeral setal formula 3-1-3-3; epimeral setae medium long, setiform, thin, smooth. Discidium rounded distally.

Anogenital region ( Figs 7B , 8B ). Five pairs of genital, one pair of aggenital, two pairs of anal and three pairs of adanal setae setiform, thin, smooth; g 1 distinctly longer than other genital setae; anal setae slightly shorter than adanal setae. Seta ad 1 inserted anterolateral to anal aperture, at level slightly anterior to an 2. Distance ad 3 – ad 3 much shorter than ag–ag. Adanal lyrifissure located laterally, adjacent and parallel to anal aperture.

Legs. Morphology of leg segments, setae and solenidia typical for Suctobelbidae . Tarsi with smooth claw. Formula of leg setation: I (1-5-2-4-20), II (1-5-2-4-13), III (2-3-1-3-13), IV (1-2-2-3-10); formula of solenidia: I (1-2-2), II (1-1-2), III (1-1-0], IV (0-1-0].

Material examined. Holotype (female): Wirye Park , Seongnam-shi, Gyeonggi Province, Korea, from a mixed forest, soil and litter under broad leaved trees, Coll. Y.S. Bae, 10 July 2023.

Distribution and habitat ecology. Currently, this species is known only from the type locality, Wirye Park in Central Korea, and is an inhabitant of the litter and soil of deciduous forest.

Etymology. The specific name “ wiryeca ” refers to the name of a historical and cultural park in the Gyeonggi Province of Korea, from which we discovered this species.

Remarks. The new species easily differentiates from the other known species of Suctobelbella (Ussuribata) by the long, strongly barbed notogastral setae of c, l - and h -series, and smooth bothridial seta. Among the known species of this subgenus, the following species, S. (U.) bivittata ( Hammer, 1979), S. (U.) womersleyi ( Balogh, 1968) , both known from the Oriental region, and S. (U.) chinonei Subías, 2017 known from East Asia, resemble the new species in the similar structure of notogastral setae (see Balogh 1968; Hammer 1979; Chinone 2003; Bayartogtokh & Bae 2024).

However, the first species, S. (U.) bivittata clearly differs from the present new species in the distinctly barbed bothridial setae (vs. smooth in new species); six pairs of genital setae (vs. five pairs in new species); presence of large medial cavity in the epimeral region (vs. absent in new species); finely barbed, thin notogastral setae (vs. heavily barbed, thick in new species); central part of prodorsum reticulate (vs. tuberculate in new species); subtriangular median prodorsal tubercle (vs. irregular oval in new species); much smaller and well-separated medial and lateral humeral tubercles (vs. large and adjacent in new species); and much larger body size (189 vs. 220 μm).

The second species, S. (U.) womersleyi is different from the present new species in the distally pointed, clearly ciliate bothridial seta (vs. distally rounded, smooth bs in new species); only distal part of notogastral setae la, lm, lp, h 2 and h 3 heavily ciliate, thickened distally (vs. setae c, l - and h -series strongly barbed throughout, pointed distally in new species); rostrum with three rather long teeth of subequal size (vs. with one large and 2–3 small teeth in new species); small humeral tubercles (vs. humeral tubercles large in new species); and much larger body size (189 vs. 262 μm).

The third species, S. (U.) chinonei is clearly distinguishable from the present new species by the bothridial seta with capitate head barbed laterally (vs. clavate and smooth bs in new species); six pairs of genital setae (vs. five pairs in new species); thin, smooth notogastral setae (vs. setae c, l - and h -series strongly barbed in new species); and much larger body size (189 vs. 234 μm).

Figures

FIGURE 7. Line drawing images of Suctobelbella (Ussuribata) wiryeca sp. nov. (legs except basal part not illustrated). A— Dorsal view; B—Ventral view; C—Lateral view of rostrum.

FIGURE 8. Compound microscopic images of Suctobelbella (Ussuribata) wiryeca sp. nov. A—Dorsal view; B—Ventral view; C—Prodorsum and anterior part of notogaster; D—Dorsal view of rostrum.