Eremella vazdemelloi, Ermilov & Frolov, 2019

Ermilov, Sergey G. & Frolov, Andrey V., 2019, Contribution to the knowledge of the oribatid mite genus Eremella (Acari, Oribatida, Eremellidae), Acarologia 59 (2), pp. 214-226 : 215-222

Eremella vazdemelloi sp. nov.

Zoobank: 034FC270-6CA6-414A-B2DA-E694C483CFAA ( Figures 1–6)

Diagnosis — Body size: 232–265 × 132–157. Body surface densely tuberculate and microgranulate. Costulae long. Tutorial ridges absent. Rostral, lamellar, interlamellar and exobothridial setae short, setiform, barbed; le thickest. Bothridial setae of medium size,

with slightly flattened, clavate, barbed head, always directed posterolaterally or posteriorly. Notogastral setae short, setiform, with curved tip, minutely barbed. Epimeral and anogenital setae short, setiform, minutely barbed. Six pairs of genital setae.

Description

Measurements — Body length: 249 (holotype: female), 232–265 (47 paratypes: 32 females and 15 males); notogaster width: 149 (holotype), 132–157 (47 paratypes). No clear difference between females and males in body size.

Integument — ( Figs 1a, b, 2a–d, 3a–d, 4a–d, 5a–c, 6a, g, i). Body light brown. Body surface (including genital and anal plates) and all leg femora and trochanters III, IV with dense tubercles (their diameter up to 6), which are covered by numerous microgranules (their diameter less than 1); tubercles often connected by slightly developed ridges. Subcapitular mentum with tubercles and striae. Leg genua, tibiae and tarsi with dorsal and paraxial ridges.

Prodorsum — ( Figs 1a, 2b, 4a–d, 6b–e). Rostrum broadly rounded. Costulae long, usually distinctly developed ( Fig. 4a), rarely poorly visible ( Fig. 4b), located dorsally between rostral setae and bothridia. Tutorial ridges completely absent. Rostral (14–16), lamellar (10–12), interlamellar (8–10) and exobothridial (8–10) setae setiform, barbed; le thickest, ex thinnest.

Bothridial setae (41–45) with short stalk and well developed, slightly flattened, clavate, barbed head, specifically directed posterolaterally or posteriorly. Bothridia with lateral thickening.

Dorsophragmata and pleurophragmata not observed.

Notogaster — ( Figs 1a, 2a–d, 4a–c, 6f). Ten pairs of notogastral setae similar in length (10–12), setiform, with curved tip, hardly barbed. Opisthonotal gland openings, lyrifissures (except ia – not found), circumgastric scissure and circumgastric sigillar band poorly visible.

Gnathosoma — ( Figs 1b–d, 2a, b, 6g). Subcapitulum longer than wide (53–57 × 36–41). Three pairs of subcapitular setae setiform; a (10–12) and h (14–16) hardly barbed, m (14–16) distinctly barbed. Two pairs of adoral setae (4–6) setiform, smooth. Palps (41–45) with setation 0-2-1-3-9(+ω). Postpalpal setae (2) thorn-like, smooth. Axillary saccules poorly visible, elongated. Chelicerae (57–61) with two setiform, barbed setae, cha (18–20) longer than chb (10–12). Trägårdh’s organ of chelicerae tapered.

Epimeral and lateral podosomal regions — ( Figs 2a, b). Epimeral setal formula 3-1-2-2. Setae setiform, hardly barbed; 1b (18–20) longer than 3b, 4a, 4b (18) and 1a, 1c, 2a, 3a (10–12). Discidia broadly triangular.

Anogenital region — ( Figs 2a–e, 6h, i). Six pairs of genital, one pair of aggenital, two pairs of anal and three pairs of adanal setae similar in length (10–12), setiform, hardly barbed. Adanal lyrifissures located close and parallel to anal plates. Preanal organ small, slightly elongate, conical. Ovipositor elongated (length 65–71, width of cylindrical part 20), blades (24–26) shorter than length of distal section (beyond middle fold; 41–45). Each of the three blades with four smooth setae, ψ1 ≈ τ1 (30–32) setiform, ψ2 ≈ τa ≈ τb ≈ τc (10–12) thorn-like. Coronal setae not observed.

Legs — ( Figs 3a–d, 4a–c, 5c, d). Median claw slightly thicker than lateral claws, all strong, smooth. Porose areas on femora I–IV slightly visible, located dorsoparaxially on femora I, II and posteroparaxially on femora III, IV. Porose areas on trochanters not observed. Formulas of leg setation and solenidia: I (1-5-3-4-17) [1-2-2], II (1-5-3-4-15) [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 of tarsi I thickened, erect, truncate distally, inserted between solenidia. Solenidion φ1 on tibiae

I very long, setiform; ω1 and ω2 on tarsi I and φ2 on tibiae I comparatively long, distinctly or slightly thickened, blunt-ended, ω1 specifically curved; other solenidia comparatively short, bacilliform. Dorsoanterior apophysis of tibiae I (bearing both solenidia) well developed.

Material examined — Holotype (female) and 47 paratypes (32 females and 15 males): Brazil, Mato Grosso State, Cuiabá, Flor do Cerrado, 15°29ʹ38″S 56°4ʹ36″W, termite nest ( Cornitermes silvestrii ) in small patch of Cerradão , a forest-like subtype of the Cerrado , 27.II.2017 (collected by A. V. Frolov).

Type deposition — The holotype and one paratype are deposited in the collection of UNESP —Universidade Estadual Paulista, Department of Zoology and Botany, 15054–000

São José do Rio Preto–SP, Brazil; registration numbers: 1739.1 and 1740.1, respectively.

Five paratypes are deposited in the Acarology collection of the Zoological Institute, Russian Academy of Sciences, Saint-Petersburg, Russia. Three paratypes are deposited in the collection of the Senckenberg Institute, Görlitz, Germany. Thirty eight paratypes are deposited in the Tyumen State University Museum of Zoology, Tyumen, Russia. All in ethanol with a drop of glycerol.

Etymology — The new species is named after Dr. Fernando Vaz-de-Mello (Federal University of Mato Grosso, Cuiabá, Brazil), the leading scarab beetle researcher in Brazil.

Remarks — Eremella vazdemelloi sp. nov. is morphologically most similar to Eremella ensifera Balogh and Mahunka, 1968 in having tuberculate body surface and setiform notogastral setae, but differs from the latter by the presence of short notogastral setae (versus medium size), the bothridial setae specifically directed posterolaterally or posteriorly (versus laterally), and the absence of tutorial ridges (versus present).