Perscheloribates (Perscheloribates) parakontumensis, 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 : 295-299

Perscheloribates (Perscheloribates) parakontumensis n. sp.

Zoobank: 0E24D8AB-6CBD-4AF0-BFDD-0A7CE11E7EE3

( Figures 4–6 )

Diagnosis — Body size: 348–365 × 182–199. Rostrum pointed. Prolamella and translamella absent. Rostral, lamellar and interlamellar setae long, setiform, barbed; ro shortest, in longest. Bothridial seta long, lanceolate, with long, setiform apex, barbed. Lateral keel-shaped ridge present. Notogastral setae short, setiform, roughened. Epimeral and anogenital setae setiform, roughened.

Description — Measurements – Small species. Body length: 348 (holotype, female), 348– 365 (three paratypes, one male and two females); notogaster width: 182 (holotype), 182–199 (three paratypes).

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

Prodorsum ( Figs 4a , 5a ) – Rostrum pointed. Lamella located dorsolaterally, about half of prodorsum (measured in lateral view). Sublamella thin, similar to lamella in length. Sublamellar porose area (4) rounded. Prolamella absent, but its basal part sometimes developed. Translamella absent. Rostral (53–61), lamellar (69–73) and interlamellar (77–82) setae setiform, barbed. Bothridial seta (65–73) lanceolate, barbed, with long stalk and shorter head having long setiform apex. Exobothridial seta (20–24) setiform, slightly barbed. Alveolar vestige of second exobothridial seta and lateral keel-shaped ridge present. Sejugal porose area not observed. Dorsophragma slightly elongated.

Notogaster ( Figs 4a , 5 a-c) – Anterior notogastral margin convex medially. Pteromorph triangular, broadly rounded distally. Ten pairs of notogastral setae (10–12) setiform, roughened. Four pairs of sacculi with small opening and drop-like chamber. Distance S1–S1 shorter than S2–S2. Opisthonotal gland opening and all lyrifissures distinct. Circumgastric scissure often not observed. Circumgastric sigillar band visible.

Gnathosoma ( Fig. 4b ) – Similar to Perscheloribates paracuriosus n. sp. Subcapitulum longer than wide (82–90 × 65–73). Three pairs of subcapitular setae setiform, barbed; h (24– 28) longer than a (18–20) and m (10–12), m thinnest. Two pairs of adoral setae (10) 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 (32–36) longer than chb (16–20). Trägårdh’s organ narrowly triangular.

Epimeral and lateral podosomal regions ( Figs 4b , 5a ) – Epimeral setal formula 3-1-3-3. Setae setiform, roughened; 1b, 1c, 3b, 3c, 4c (16–24) longer than 1a, 2a, 3a, 4a, 4b (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 4b , 5 a-c) – Four pairs of genital (8–10), one pair of aggenital (10–12), two pairs of anal (10–41) and three pairs of adanal (10–12) setae setiform, roughened. Adanal lyrifissure located close and parallel to anal plates. Marginal porose area complete, band-like. Preanal organ of typical, goblet-like form. Ovipositor elongated (134 × 28), blade (61) shorter than length of distal section (beyond middle fold; 73). Each of the three blades with four smooth setae, ψ 1 ≈ τ 1 (24) setiform, ψ 2 ≈ τa ≈ τb ≈ τc (12) thorn-like. Six coronal setae (2) spiniform.

Legs (Figs 6a-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 (1-5-3-4-19) [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 2. Seta it present on all tarsi. 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 (female) and three paratypes (one male and two females):

U.S.A., Michigan, Emmet Co., Wilderness State Park, 45°44’N, 84°55’W, phoretic on specimens of Phellopsis obcordata (Kirby, 1873) (Coleoptera, Zopheridae), May 1981 (J. Kukor). Host specimen in UMMZ bearing the voucher label, “Mites removed, B.M. OConnor #81-0604-001.” Mites were found on 3 specimens of P. obcordata collected from a fruting body of the polypore fungus, Porodaedalea pini (Brot.) Murrill, 1905 (= Fomes pini, = Phellinus pini), growing on red pine, Pinus resinosa Alton, 1789. Mites were found in pits on the dorsal surface of the elytra. The habitat consists of around 4050 hectares of dense coniferous and mixed hardwood forest on the northeast shore of Lake Michigan. The host beetle is associated with several species of polypore fungi in dense boreal forests in Eastern North America (Evans 2014), suggesting that the normal habitat of this mite species is either on or in the fungal fruiting bodies or in the mycelium growing within the wood of the host tree.

Type deposition — The holotype and two paratypes 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.

Note: See Table 1 for explanation.

Etymology — The species name parakontumensis refers to the similarity between the new species and Perscheloribates kontumensis Ermilov & Frolov, 2019 .

Remarks — In the presence of pointed rostrum, lanceolate bothridial head with long setiform apex and developed notogastral setae, and in the absence of prolamella, the new species is similar to Perscheloribates kontumensis Ermilov & Frolov, 2019 from Vietnam (see Ermilov & Frolov 2019a), but differs from the latter by the presence of simple notogastral setae (versus with flexible tip in P. kontumensis ) and the absence of body sculpturing (versus simple in P. kontumensis ) and setae it on leg tarsi I–III (versus absent in P. kontumensis ).

Figures

Figure 4 Perscheloribates parakontumensis n. sp., adult: a – dorsal view; b – ventral view (legs omitted). Scale bar 100 μm.

Figure 5 Perscheloribates parakontumensis n. sp., adult: a – anterior part of body, lateral view (gnathosoma and legs omitted); b – posterior

Figure 6 Perscheloribates parakontumensis n. sp., adult: a – leg I, right, antiaxial view; b – leg II, without tarsus, right, antiaxial view; c – leg III, without tarsus, right, antiaxial view; d – leg IV, left, antiaxial view. Scale bar 50 μm.