Perscheloribates (Perscheloribates) paracuriosus, Ermilov & OConnor, 2020

Ermilov, Sergey G. & OConnor, Barry M., 2020, New Perscheloribates species (Acari, Oribatida, Scheloribatidae) phoretic on beetles (Insecta, Coleoptera), Acarologia 60 (2), pp. 289-300 : 290-295

Perscheloribates (Perscheloribates) paracuriosus n. sp.

Zoobank: 4637B85A-2B7A-46E5-BCEB-1BD63BD07E7D

( Figures 1–3 )

Diagnosis — Body size: 348–381 × 166–199. Rostrum pointed. Prolamella and translamella absent. Rostral, lamellar and interlamellar setae long, setiform, barbed; ro shortest, in longest. Bothridial seta long, lanceolate, barbed. Lateral keel-shaped ridge present. Notogastral seta short, setiform, roughened, c, la, lm short, simple, others longer, flexible. Epimeral and genital setae setiform, roughened. Anal and adanal setae flexible, roughened. Leg seta it absent on all tarsi.

Description — Measurements – a relatively small species. Body length: 365 (holotype, male), 348, 381 (two paratypes, two females); notogaster width: 182 (holotype), 166, 199 (two paratypes).

Integument – Body color light brown. Body surface punctate (visible under high magnification in dissected specimens). Lateral part of prodorsum slightly microgranulate.

Prodorsum (Figs 1a, 2a) – Rostrum pointed. Lamella located dorsolaterally, about half of prodorsum (measured in lateral view). Sublamella thin, slightly shorter than lamella. Sublamellar porose area (4) rounded. Prolamella and translamella absent. Rostral (53–57), lamellar (65–73) and interlamellar (102–110) setae setiform, barbed. Bothridial seta (82–86) lanceolate, barbed, with long stalk and shorter pointed apically head. Exobothridial seta (12–16) setiform, roughened. Alveolar vestige of second exobothridial seta and lateral keel-shaped ridge present. Sejugal porose area not observed. Dorsophragma slightly elongated.

Notogaster (Figs 1a, 2a-c) – Anterior notogastral margin convex medially. Pteromorph triangular, broadly rounded distally. Ten pairs of notogastral setae setiform, roughened, with different length and morphology; c, la, lm shorter (12–16), simple, others distinctly longer lp (, 24–36; others 32–41), with flexible tip. Four pairs of sacculi with small opening and drop-like chamber. Distance S1–S1 equal S2–S2. Opisthonotal gland opening and all lyrifissures distinct. Circumgastric scissure not observed. Circumgastric sigillar band visible.

Gnathosoma ( Figs 2 d-g) – Subcapitulum longer than wide (82–86 × 65–73). Three pairs of subcapitular setae setiform, barbed; h (28–32) longer than a (20–24) and m (20–24). Two pairs of adoral setae (10–12) setiform, barbed. Palp (49–53) with setation 0-2-1-3-9(+ω). Postpalpal seta (4) spiniform. Chelicera (90–94) with two setiform, barbed setae, cha (41–32) longer than chb (16–20). Trägårdh’s organ narrowly triangular.

Epimeral and lateral podosomal regions ( Figs 1b , 2a ) – Epimeral setal formula 3-1-3-3. Setae setiform, roughened; 1b and 3b (24–28) longer than 1c, 3c, 4a, 4b, 4c (16–20) and 1a, 2a, 3a (10–12). Setae 1c inserted laterally on pedotectum I. Pedotectum II quadrangular in ventral view, with one protruding tip. Discidium rounded distally. Circumpedal carina long, reaching pedotectum II.

Anogenital region ( Figs 1b , 2 a-c) – Four pairs of genital (10–12) and one pair of aggenital (12–14) setae setiform, roughened. Two pairs of anal (32–41) and three pairs of adanal (32–41) setae flexible, roughened. Adanal lyrifissure located close and parallel to anal plates. Marginal porose area not observed. Preanal organ of typical, goblet-like form. Ovipositor elongated (138 × 20), blade (65) shorter than length of distal section (beyond middle fold; 73). Each of the three blades with four smooth setae 1, ψ ≈ τ 1 (24) setiform, ψ 2 ≈ τa ≈ τb ≈ τc (12) thorn-like. Six coronal setae (2) spiniform.

Legs ( Figs 3 a-d) – Claw of leg pretarsus sparsely barbed on dorsal side. Porose area on femora I–IV and on trochanters III, IV slightly visible; ventral porose area in basal part of tarsus and distal part of tibia not observed. Formulas of leg setation and solenidia: I (1-5-2-4-17) [1-2-2], II (1-5-2-4-13) [1-1-2], III (2-3-1-3-13) [1-1-0], IV (1-2-2-3-11) [0-1-0]; homology of setae and solenidia indicated in Table 1 . Seta it absent on all tarsi, seta a’ absent on tarsus IV. Famulus of tarsus I short, erect, slightly swollen distally, inserted between solenidion ω 1 and seta ft”. Solenidion ω 1 on tarsus I, ω 1 and ω 2 on tarsus II and σ on genu III bacilliform, other solenidia setiform.

Material examined — Holotype (male) and two paratypes (two females): Philippines, Negros Oriental, Sibulan Municipality, Lake Balinsasayao, 09°21’N, 123°10’E, 835 m a.s.l., phoretic on a specimen of Aceraius lamellatus Gravley, 1918 ( Coleoptera , Passalidae ), 9 August 1982 (P.D. Heideman). Data on localization of mites on A. lamellatus was not reported. Host specimen in the University of Michigan Museum of Zoology ( UMMZ) bearing the voucher label, “Mites removed, B.M. OConnor #83-1800-024.” The host specimen was collected in a decaying log in primary dipterocarp forest.

Type deposition — The holotype and one paratype are deposited in the collection of the University of Michigan Museum of Zoology, Ann Arbor, MI, USA; one paratype is deposited in the collection of the Tyumen State University Museum of Zoology, Tyumen, Russia. All specimens are stored in ethanol with a drop of glycerol.

Etymology — The species name paracuriosus refers to the similarity between the new species and Perscheloribates curiosus Ermilov, 2016 .

Remarks — In the presence of a pointed rostrum, lanceolate bothridial head and developed notogastral setae, and in the absence of prolamella, the new species is similar to Perscheloribates curiosus Ermilov, 2016 from Cuba (see Ermilov & Tolstikov 2016), but differs from the latter by the morphological differentiation of the notogastral setae c, (la, lm short, simple; others distinctly longer, flexible) (versus all setae short, similar in length, simple in P. curiosus ), the presence of flexible anal and adanal setae (versus simple in P. curiosus ) and a keel-shaped ridge on the lateral side of the prodorsum (versus absent in P. curiosus ), and the absence of custodium (versus present in P. curiosus ).

Figures

Figure 1 Perscheloribates paracuriosus n. sp., adult: a – dorsal view; b – ventral view (gnathosoma and legs omitted). Scale bar 100 μm.

Figure 2 Perscheloribates paracuriosus n. sp., adult: a – anterior part of body, lateral view (gnathosoma and legs omitted); b – posterior part

Figure 3 Perscheloribates paracuriosus n. sp., adult: a – leg I, left, paraxial view; b – leg II, without tarsus, left, paraxial view; c – leg III, without tarsus, left, antiaxial view; d – leg IV, left, antiaxial view. Scale bar 50 μm.