Idiozetes schusteri, ErmilovK & SalavatulinK, 2024

ErmilovK, Sergey G. & SalavatulinK, Vladimir M., 2024, Contribution to knowledge of the oribatid mite genus Idiozetes (Acari, Oribatida, Idiozetidae), with description of a new sexually dimorphic species from Vietnam, Acarologia 64 (3), pp. 768-776 : 770-774

Idiozetes schusteri sp. n.

Zoobank: 8E07C15D-0400-48F5-9965-6BC34FE12CE1

( Figures 1–3 )

Type material

Holotype (male) and six paratypes (three males and three females): Vietnam, Dong Nai Province, Dong Nai Biosphere Reserve, Cat Tien National Park , litter under Dipterocarpus alatus and Haldina cardifolia , 20.XI.2022 – 10.XII.2022 (collected by V.M. Salavatulin and A.A. Kudrin).

Additional (non-type) material: six specimens (three males and three females): same data as for the type material but from bark (at the height of 13 m) and branches (at the height of 25 m) of Dipterocarpus alatus .

The holotype is deposited in the collection of the Senckenberg Museum of Natural History, Görlitz, Germany; six paratypes and non-type material 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.

Diagnosis

Body length: 307–360. Pteromorphs and notogaster posterolateral to lenticulus partially striate. Tutoria fused dorsally on prodorsum forming bidentate structure. In males, posterior part of notogaster with two large tubercles (versus tubercles absent in females). Nine pairs of notogastral setae. Five pairs of saccules. Epimeral setal formula: 2–1–2–2. Eight pairs of genital setae. Monodactylous.

Description

Measurements – Body length: 307 (holotype), 307–330 (male paratypes), 345–360 (female paratypes); notogaster width: 150 (holotype), 150–165 (male paratypes), 195–210 (female paratypes).

Integument – Body color brown. Body covered by thick cerotegument including black dirt and debris forming blocky structure. Surface densely microporose (visible only under high magnification in dissected specimens); pteromorph and notogaster posterolateral to lenticulus partially striate.

Prodorsum ( Figures 1A, B ; 2A, C) – Rostrum broadly rounded. Lamella distally triangular. Tutoria broad, fused dorsally on prodorsum forming bidentate structure. Rostral (13–15) and lamellar (22–26) setae setiform, roughened; bothridial seta (86–94) with long, roughened stalk and short, unilaterally dilated, flattened, barbed head.

Notogaster ( Figures 1A, B ; 2A–C ; 3A, B) – Five pairs of saccules, with small opening and bacilliform (often furcate) channel. In males, posterior part of notogaster with two large tubercles (versus tubercles absent in females), bearing opening of sacculus S4. Nine pairs of notogastral setae, posterior setae (p 1 – p 3) longer than others (13–15 versus 7–9), all setiform, roughened. Opisthonotal gland opening and all lyrifissures distinct.

Gnathosoma ( Figures 3C–F ) – Subcapitulum size: 73–82 × 49–53; subcapitular setae (a: 15; m: 9–11; h: 11–13) setiform, roughened; m thinnest, a thickest; both pairs of adoral setae (9–11) setiform, barbed. Small depression located posterior to h. Palp length: 45–49; postpalpal seta (7) spiniform, roughened. Chelicera length: 73–82; setae (cha: 26–28; chb: 11–13) setiform, barbed.

Epimeral and lateral podosomal regions ( Figures 1B , 2C ) – Sejugal region concave. Epimeral setal formula: 2–1–2–2; setae 1a, 2a, 3a (4) spiniform smooth, others (13–15) setiform, roughened. Parastigmatic apophysis Sa thorn-like. Discidium broadly rounded.

Anogenital region ( Figures 1B ; 2C, 3A, B) – Genital (7–9), anal (13–15), adanal (13–15) setae setiform, roughened; eight pairs of genital setae; left anal plate of the holotype with two setae. Adanal lyrifissure close and parallel to anterior half of anal plate.

Legs ( Figures 3G–J ) – Monodactylous; claw strong, slightly barbed dorsally. Lateroparaxial porose area on femora I–IV and on trochanters III, IV well visible. Formulas of leg setation and solenidia: I (1–4–3–4–16) [1–2–2], II (1–4–3–4–15) [1–1–2], III (0–2–1–3–15) [1–1–0], IV (0–1–2–3–14) [0–1–0]; homology of setae and solenidia indicated in Table 1 . Famulus medium-sized, rod-like. Solenidion 1 φon tibia I subflagellate; ω 1 and ω 2 on tarsi I and II, and φ 2 on tibia I rod-like; other solenidia slightly bacilliform.

Remarks

Idiozetes schusteri sp. n. differs from the other species of the genus in combination of the following morphological traits: sexually dimorphic (males smaller and with two large tubercles in posterior part of notogaster); tutoria fused dorsally on prodorsum forming bidentate structure; nine pairs of notogastral setae (c, la, lm, h 1 – h 3, p 1 – p 3); five pairs of notogastral saccules; eight pairs of genital setae; monodactylous. Distinctive characters of the new species from the other species of the genus Idiozetes can be found in the identification key below.

Etymology

This species is named in honor the well-known acarologist Reinhart Schuster (1930–2023), Professor Emeritus of Karl-Franzens-University Graz, Austria ( Krisper et al. 2023).

Figures

Figure 1 Idiozetes schusteri sp. n., adult, female (gnathosoma and legs not shown): A — dorsal view; B — ventral view. Scale bar 50 μm.

Figure 2 Idiozetes schusterisp. n., adult, male (A, B) and female (C) (gnathosoma and legs not shown): A — dorsal view of notogaster; B — right lateral view of notogaster; C — right lateral view. Scale bars 50 μm.

Figure 3 Idiozetes schusteri sp. n., adult, male (A) and female (B–J): A, B — posterior view; C — subcapitulum (dissected), ventral view; D — left lip with adoral seta, ventral view; E — palp, right, antiaxial view; F — chelicera, left, paraxial view; G — tibia and tarsus of leg I, right, antiaxial view; H — trochanter and femur of leg I, left, paraxial view; I — tibia and tarsus of leg II, left, paraxial view; J — leg IV, right, paraxial view. Scale bars 50 μm (A, B), 25 μm (G–J), 20 μm (C, D, F), 10 μm (E).