Zetorchella arsiensis Ermilov, 2023

Ermilov, S. G. & Rybalov, L. B., 2023, A new species of the genus Zetorchella Berlese, 1916 (Acari: Oribatida: Caloppiidae) from Ethiopia, with a key to species of the genus from Afrotripical region, Far Eastern Entomologist 469, pp. 1-10 : 3-8

Zetorchella arsiensis Ermilov , sp. n.

https://zoobank.org/NomenclaturalActs/ F52F4DCE-0C94-43E1-A012-3A777D37EE57

Figs 1–16

TYPE MATERIAL. Holotype – ♀, Ethiopia: Oromia Region, Arsi Zone, Arsi Mountains National Park, Mount Chilalo, 07º56′09.5′′N, 039º11′54.7′′E, 3177 m a.s.l., sifting litter under Hypericum sp. , Thyme sp. and green mosses in heather bushes ( Erica arborea ), Berlese's funnels, 27.XI 2021, leg. L.B. Rybalov. Paratypes: 7♂, 4♀, same data as holotype .

TYPE DEPOSITION. The holotype is deposited in the collection of the Senckenberg Museum of Natural History , Görlitz, Germany; 11 paratypes are deposited in the collection of the Tyumen State University Museum of Zoology , Tyumen, Russia. All specimens are preserved in ethanol with a drop of glycerol.

DIAGNOSIS. Body length: 796–898. Interlamellar, epimeral and anogenital regions foveate; notogaster foveolate; genital plate striate. Interlamellar seta medium-sized, slightly phylliform, barbed. Bothridial seta comparatively short, clavate, barbed. Notogaster with sinuous ridges. All notogastral setae comparatively short, phylliform (dilated mediodistally), barbed. Epimeral and anogenital setae setae setiform, slightly barbed. With two pairs of adanal setae. Leg tarsus I with 19 setae (l” absent).

MEASUREMENTS. Body length: 830 (holotype), 796–898 (11 paratypes); body width: 597 (holotype), 531–614 (11 paratypes).

DESCRIPTION. Integument. Body color brown to dark brown. Body surface densely microgranulate. Anterior part of prodorsum foveate-reticulate. Interlamellar, epimeral and anogenital regions, subcapitular mentum, leg trochanters III, IV, and podosomal region between bothridium and acetabula III, IV foveate (cells or semicells of different form with strong ridge-like borders between them). Notogaster foveolate (rounded cells). Genital plate longitudinally striate. Leg femora I-IV microfoveate. Marginal region of ventral plate with numerous small tubercles forming often chain-like structures.

Prodorsum. Rostrum widely rounded. Lamella about 1/2 length of prodorsum. Prolamella absent. Sublamella slightly shorter than lamella. Sublamellar porose area rounded (6–8), located ventral to sublamella. Tutorium similar to lamella in length, ridge-like, reaching insertion of rostral seta. Rostral (135–149) and lamellar (180–192) setae setiform, barbed. Interlamellar seta (102–114) slightly phylliform and dilated distally, barbed. Exobothridial seta (69–73) setiform, thin, barbed. Bothridial seta (61–77) clavate, barbed, with stalk and head similar in length. Dorsosejugal porose area not observed.

Notogaster. Anterior notogastral margin distinct, slightly convex medially. Humeral process slight, elongate quadrangular. Notogaster with some slightly developed (but well visible) sinuous ridges. Ten pairs of notogastral setae (61–77) phylliform (dilated mediodistally), barbed. Five pairs of porose areas rounded (6–8). Opisthonotal gland opening and all lyrifissures distinct.

Gnathosoma. Subcapitulum size: 180–205 × 139–164. Subcapitular (a: 30–32; m and h: 49–61) and adoral (16) setae setiform, barbed. Palp (135–151) setation: 0– 2–1–3–9(+ω). Postpalpal seta (8) spiniform, roughened. Chelicera (186–205) with two setiform, barbed setae (cha: 61–69; chb: 41–49).

Epimeral and lateral podosomal regions. Epimeral setal formula: 3–1–3–3. Setae (1a, 2a, 3a: 41–49; 1c, 3c, 4c: 65–73; others: 49–61) setiform, slightly barbed. Circumpedal carina sharply defined, originating from anogenital region, and then curving to approach circumgastric scissure asymptotically, ending below humeral process strong. Discidium strong, subtriangular.

Anogenital region. Genital (32–36), aggenital (41–49), anal (32–36), and adanal (41–49) setae setiform, slightly barbed. Two pairs of adanal setae present; seta ad 1 thicker than ad 2 in some paratypes. Adanal lyrifissure located close and parallel to anal plate. Marginal porose area absent.

Legs. Tridactylous. Median claw slightly thicker than lateral claws, all barbed on dorsal side; each lateral claw with small tooth ventrodistally. Tibia I with small dorsodistal apophysis bearing solenidia φ 1 and φ 2. Dorsal porose area on tarsi I, II, dorsoparaxial porose area on femora I–IV and on trochanters III, IV, proximoventral porose area on tarsi I-IV, and distoventral porose area on tibiae I-IV well observed; proximoventral and distoventral porose areas divided into two parts. Formulas of leg setation and solenidia: I (1–5–3–4–19) [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 . Famulus short, erect, slightly swollen distally, inserted between solenidion ω 2 and seta ft”. Seta s on tarsus I eupathidial, located between setae u and a.

REMARKS. Zetorchella arsiensis Ermilov , sp. n. is morphologically most similar to the other Ethiopian species Zetorchella robertbecki Ermilov, Subías, Shtanchaeva et Friedrich, 2021 in having striate genital plates, two pairs of adanal setae and 10 pairs of phylliform notogastral setae. However, the new species differs from the latter by the larger body size (796–898 × 531–614 versus 481–614 × 348– 464) and the presence of medium-sized bothridial seta similar to notogastral setae in length (versus bothridial seta long, about 1.7 length of notogastral setae), welldeveloped foveolae and slightly developed sinuous ridges on the notogaster (versus foveolae poorly observed; ridges completely absent), heavily foveate anogenital region (versus anogenital region slightly foveolate), and foveolate anal plate (versus anal plate foveate-reticulate).

DISTRIBUTION. Ethiopia.

ETYMOLOGY. The species name arsiensis refers to the place of origin, Arsi Mountains National Park.

Figures

Figs 1–3. Zetorchella arsiensis Ermilov, sp. n., adult: 1 – dorsal view (legs not shown); 2 – ventral view (gnathosoma and legs not shown); 3 – right lateral view (gnathosoma and legs not shown). Scale bar = 100 μm.

Figs 4–10. Zetorchella arsiensis Ermilov, sp. n., adult: 4 – subcapitulum, ventral view; 5 – chelicera, left, paraxial view; 6 – palp, left, antiaxial view; 7 – leg I, right, antiaxial view; 8 – leg II, without trochanter and tarsus, right, antiaxial view; 9 – leg III, without tarsus, right, antiaxial view; 10 – leg IV, left, antiaxial view. Scale bar 20 μm (4–6), 50 μm (7–10).

Figs 11–14. Zetorchella arsiensis Ermilov, sp. n., adult, SEM micrographs: 11 – dorsal view; 12 – ventral view; 13 – lateral view; 14 – ventrolateral view.

Figs 15, 16. Zetorchella arsiensis Ermilov, sp. n., adult, SEM micrographs: 15 – anterodorsal view; 16 – notogastral seta h1.