Euscheloribates magdiwangensis, Ermilov K & K, 2022

Ermilov K, Sergey G. & K, Leonila Corpuz- Raros, 2022, Two new species of Euscheloribates (Acari, Oribatida, Scheloribatidae) from the Philippines, Acarologia 62 (3), pp. 811-820 : 816-818

Euscheloribates magdiwangensis n. sp.

Zoobank: EA8D40AF-4219-4543-95AE-99B0A7379957

( Figures 2b, d , 4 a-c;)

Diagnosis — Body length: 265–298. Rostrum rounded. Translamella represented by two short ridges directed backwards. Tutorium present. Rostral and lamellar setae long, setiform, slightly barbed; interlamellar seta long, setiform, erect, barbed; ro shortest, le longest. Bothridial seta with short stalk and elongate clavate, slightly barbed head. Anterior notogastral margin distinctly convex medially. All notogastral setae short, setiform, slightly flexible, smooth. Epimeral and anogenital setae short, setiform, smooth; both aggenital setae present; each anal plate with two setae. Circumpedal carina long. Leg tarsus I with 16 setae, tarsus III with 13 setae, trochanter III with one seta, genu IV with one seta.

Description of adult — Measurements – Body length: 265 (holotype, male), 298 (two paratype females), 265 (one paratype male); body width: 132 (holotype), 149, 166 (two paratype females), 132 (one paratype male).

Integument – Body color brown. Cuticle microporose (visible in dissected specimens under high magnification, ×1500).

Prodorsum – Rostrum slightly protruding, rounded. Lamella about 1/2 length of prodorsum. Prolamella lineate. Sublamella about 2/3 length of prodorsum. Sublamellar porose area rounded (4–6) or oval (8 × 4). Translamella absent, only two short ridges developed near lamellae, directed backwards. Tutorium medium-sized, simple. Rostral (28–32) and lamellar (49–53) setae setiform, slightly barbed. Interlamellar seta (36–41) setiform, erect, barbed. Exobothridial seta represented by alveolus. Bothridial seta (24–30) with short (4–6), smooth stalk and longer (20–24), elongate clavate, slightly barbed head. Bothridium with lateral scale. Dorsosejugal porose area oval (6 × 2–4). Dorsophragma distinctly elongate.

Notogaster – Anterior notogastral margin distinctly convex medially. Ten pairs of notogastral setae (14–16) setiform, thin, slightly flexible, smooth. Four pairs of sacculi drop-like; S3 smallest, sometimes poorly visible. Opisthonotal gland opening and all lyrifissures distinct.

Gnathosoma – Subcapitulum size: 65–69 × 45–53; subcapitular (a: 12; m, h: 16) and adoral (6) setae setiform, roughened. Palp (length: 41–45) setation: 0–2–1–3–9 (+ω); solenidion swollen distally. Postpalpal seta (4) spiniform, smooth. Chelicera (length: 65–69) with two setiform, barbed setae cha (: 24; chb: 16).

Epimeral and lateral podosomal regions – Epimeral formula: 3–1–2–2; setae (c: 4; others: 10–12) setiform, thin, smooth. Humeral porose area Ah distinct; Am not observed. Pedotecta I,

II represented by small laminae; pedotectum II rounded distally in ventral aspect. Discidium triangular, rounded distally. Circumpedal carina comparatively long, anteriorly reaching pedotectum II.

Anogenital region – Three pairs of genital (10–12), one pair of aggenital (10–12), two pairs of anal (10–12), and three pairs of adanal (12–14) setae setiform, thin, smooth. Adanal lyrifissure distinct. Marginal porose area not observed.

Legs – Claw slightly barbed on dorsal side. Porose area on all femora and on trochanters III, IV well visible; porose area on all tarsi and tibiae absent. Formulas of leg setation and solenidia: I (1–5–2–4–16) [1–2–2], II (1–5–2–4–15) [1–1–2], III (1–2–1–3–13) [1–1–0], IV (1–2–1–3–12) [0–1–0]; homology of setae and solenidia indicated in Table 1. Famulus short, slightly swollen distally, inserted posterior to solenidion 2 ω; seta d on femora III, IV inserted dorsobasally on segments. Solenidion ω 1 on tarsus I, ω 1 and ω 2 on tarsus II and σ on genu III slightly bacilliform; other solenidia setiform.

Material examined — Holotype (male) and three paratypes (one male and two females): Philippines, Sibuyan Is., Romblon Province, Mt. Magdiwang, Mount Guiting-guiting Natural Park, leaf litter in forest ( Museum number: JCBN 17 0330-2), 30.III.2017 (leg. O.L. Eusebio).

Type deposition — The holotype is deposited in the collection of the Senckenberg Museum of Natural History, Görlitz, Germany ; three 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.

Etymology — The species name magdiwangensis refers ro the place of origin, Mt. Magdiwang.

Differential diagnosis — Euscheloribates magdiwangensis n. sp. is morphologically most similar to Euscheloribates mixtus ( Mahunka, 1978) from Mauritius in having aggenital setae, clavate bothridial seta with short stalk and rounded rostrum, and in the absence of complete translamella and foveolate body ornamentation. However, the new species differs from the latter by smaller body size (length: 265–298 versus 320–325), in the presence (versus absence) of two short parts of translamellar line directed backwards, longest lamellar seta on the prodorsum (versus interlamellar seta longest), 10 pairs (versus one pair p 1 developed, others represented by alveoli) of well visible notogastral setae and two pairs (versus three pairs) of setae on epimeres III and IV, and by localization of only one (versus two) genital seta in medioanterior part of genital plate.

Figures

Figure 2 Euscheloribates guitingensisn. sp., adult: a – leg I, without trochanter, right, antiaxial view; b – leg II, right, antiaxial view; c – leg III, left, antiaxial view; d – leg IV, left, antiaxial view. Scale bar 20 μm.

Figure 4 Euscheloribates magdiwangensisn. sp., adult: a – dorsal view (legs omitted); b – ventral view (gnathosoma and legs omitted); c – lateral view (gnathosoma and legs omitted). Scale bar 50 μm.