Dometorina (Dometorina) robusta, Ermilov & Salavatulin, 2023

Ermilov, Sergey G. & Salavatulin, Vladimir M., 2023, Taxonomic contribution to the knowledge of the oribatid mite family Scheloribatidae (Acari, Oribatida), with description of three new species from Vietnam, Zootaxa 5336 (2), pp. 233-246 : 234-237

Dometorina (Dometorina) robusta sp. nov.

( Figures 1 , 2 )

Type material. Holotype (female) and six paratypes (three males and three females): Vietnam, Dong Nai Province, Dong Nai Biosphere Reserve, Cat Tien National Park , 11°26′34.64′′N, 107°26′06.67′′E, about 130 m a.s.l., branches from one tree Dipterocarpus alatus at the height of 25 m (sample: PrD4), 01.XII.2022-5.XII.2022 (leg. V.M. Salavatulin and A.A. Kudrin).

The holotype is deposited in the collection of the Senckenberg Museum of Natural History, Görlitz, Germany; six paratypes are deposited in the collection of the Tyumen State University Museum of Zoology, Tyumen, Russia. All specimens are preserved in 70% solution of ethanol with a drop of glycerol.

Diagnosis. Body length: 270–315. Anogenital region partially striate. Rostrum rounded. Rostral and lamellar setae long, setiform, barbed; interlamellar seta long, robust, barbed; bothridial seta short, with globular, barbed head, entirely visible in dorsal aspect; in longer than ro and le. All notogastral setae short, setiform, thin, roughened. Four pairs of sacculi. Epimeral formula: 3-1-3-2. Aggenital setae absent.

Description. Measurements. Body length: 315 (holotype), 270–285 (male paratypes), 300–315 (female paratypes); notogaster width: 203 (holotype), 165 (male paratypes), 195–210 (female paratypes).

Integument ( Figs 1B, C ). Body light brown to brown. Surface indistinctly microsculpturing microgranulate; lateral side of prodorsum and anogenital region, regions between acetabula I and II, Am and acetabula IV partially striate.

Prodorsum ( Figs 1A, C ). Rostrum rounded. Lamella lineate, about 1/2 length of prodorsum; translamella absent; sublamella present; prolamella complete. Sublamellar porose area oval (6–7 × 2–4), poorly visible. Rostral (49–52) and lamellar (56–58) setae setiform, barbed; interlamellar seta (64) robust, acuminate, barbed; exobothridial seta (6) setiform, thin, smooth, inserted on short ridge; bothridial seta (17–19) with short stalk and globular, barbed head, entirely visible in dorsal aspect.

Notogaster ( Figs 1A, C ; 2A ). Dorsosejugal suture distinct, straight. All setae (11–15) setiform, thin, roughened. Four pairs of sacculi drop-like. Opisthonotal gland opening and all lyrifissures well visible.

Gnathosoma (2B–D). Subcapitulum size: 71–75 × 52–56; subcapitular setae (a: 13–15; m: 9–11; h: 22–26) setiform, thin, a sparsely barbed, m, h slightly roughened; m thinner than a and h; both adoral setae (9–11) setiform, barbed. Palp length: 49–52; setation: 0-2-1-3-9(+ω); postpalpal seta (6) spiniform, slightly roughened. Chelicera length: 82–90; setae (cha: 26–30; chb: 17–19) setiform, barbed.

Epimeral and lateral podosomal regions ( Figs 1B, C ). Epimeral formula: 3-1-3-2; all setae (1b: 19–22; 4a: 17– 19; 1c: 15; 3b, 3c, 4c: 11–13; 1a, 2a, 3a: 9–11) setiform, thin, roughened. Humerosejugal porose area Am diffuse. Discidium and circumpedal carina not observed.

Anogenital region ( Figs 1B, C ; 2A ). Genital (9–11), anal (11–13) and adanal (13–15) setae setiform, thin, slightly roughened; aggenital setae absent. Adanal lyrifissure close and parallel to anal plate. Ovipositor distinctly elongate (131 × 49); all blades (56) shorter than length of distal section (beyond middle fold; 75); setae ψ 1, τ 1 (19– 22) setiform, smooth; ψ 2, τ a, τ b, τ c (11) slightly stiff, acuminate, smooth; six coronal setae (4) spiniform, smooth.

Legs ( Figs 2E, F ). Empodial claw strong; both lateral claws distinctly thinner, with tubercle ventrodistally; all slightly barbed on dorsal side. Tarsal pulvillus well developed. Typical porose area on trochanters III, IV, femora I–IV, tibia I–IV, tarsi I–IV. Formulas of leg setation and solenidia: I (1-5-2-4-18) [1-2-2], II (1-5-2-4-15) [1-1-2], III (2-3-1-3-15) [1-1-0], IV (1-2-2-3-12) [0-1-0]; homology of setae and solenidia indicated in Table 1 . Solenidion ω 1 on tarsus I, ω 1, ω 2 on tarsus II, σ on genua III slightly thickened, rounded apically; φ 1 on tibia I, φ on tibiae II–IV, σ on genua I subflagellate; other solenidia setiform; φ on tibiae III, IV terminating in flattened disc. Famulus inserted posterior to ω 2.

).

Remarks. Dometorina (Dometorina) robusta sp. nov. is most similar to D. (Dometorina) rostrata Luxton, 1993 from China in the absence of aggenital setae, the presence of striate anogenital region, and by robust interlamellar setae. However, the new species differs from the latter by the morphology of the rostrum (rounded versus pointed), the localization of the bothridium (entirely visible in dorsal aspect versus covered by anterolateral part of the notogaster in dorsal aspect) and number of setae on the epimere IV (two pairs versus three pairs).

Etymology. The specific epithet robusta (“robust” in Latin) alludes to morphology of the interlamellar seta in the new species.

Figures

FIGURE 1. Dometorina (Dometorina) robusta sp. nov., adult (gnathosoma and legs omitted): A—dorsal view; B—ventral view; C—right lateral view. Scale bar 100 μm.

FIGURE 2. Dometorina (Dometorina) robusta sp. nov., adult: A—posterior view; B—subcapitulum, ventral view; C—palp, right, antiaxial view; D—chelicera, right, antiaxial view; E—leg I, right, antiaxial view; F—leg IV, left, antiaxial view. Scale bars 100 μm (A), 20 μm (B–F).