Arcoppia tetraramosa, Ermilov, 2024

Ermilov, Sergey G., 2024, Taxonomic contribution to knowledge of the oribatid mite subfamily Arcoppiinae (Acari, Oribatida, Oppiidae), Ecologica Montenegrina 73, pp. 72-81 : 73-76

Arcoppia tetraramosa sp. nov.

https://zoobank.org/ urn:lsid:zoobank.org:act:15B19BC6-0B1F-43AF-8A07-000323DFCECB

( Figs 1–11 )

Type material. Holotype (female) and four paratypes (two males and two females): eastern Guatemala, Izabal Department, Las Escobar, 8 km SW. Puerto Barrios , rainforest litter, 12–14.XI.1986 (E.E. Lindquist).

The holotype is deposited in the collection of the Canadian National Collection, Ottawa, Canada; four 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.

Diagnosis. Body length: 315–360. Basal part of prodorsum densely tuberculate. Rostrum tripartite, median part rounded, shorter than lateral ones. Costulae and transcostula forming trapezoid complex. Specific ridge-like structure present in front of transcostula. Rostral, lamellar and interlamellar setae setiform, slightly barbed; of these, le shortest, in longest; bothridial seta clavate, with four long, slightly barbed branches. All notogastral setae setiform, slightly barbed to well barbed; c well observable; lm, lp and h 2 long; la and h 3 medium-sized; other setae comparatively short; la located posterolateral to lm. Discidium rounded. Adanal lyrifissure close and parallel to anal aperture.

Description of adult. Measurements. Body length: 330 (holotype), 315 (male paratypes), 330– 360 (female paratypes); body width: 195 (holotype), 180 (male paratypes), 180–210 (female paratypes).

Integument. Body color light brown. Body surface mostly smooth but basal part of prodorsum and lateral side of body between bothridium and acetabula I, III densely tuberculate (diameter of tubercle up to 4).

Prodorsum. Rostrum tripartite, with rounded median part and longer triangular lateral ones. Costulae and transcostula fused, forming trapezoid costular-transcostular complex. Specific ridge-like structure (similar to an arch with triangular narrowness anteriorly) present in front of transcostula. Rostral (34–41), lamellar (26–30) and interlamellar (52–64) setae setiform, slightly barbed; exobothridial seta (19–22) setiform, roughened; bothridial seta (71–79) with long stalk and short, clavate head having four long, slightly barbed branches (cornicles absent); lateral branches slightly longer than medial branches. Interbothridial and postbothridial tubercles absent. Interbothridial muscle sigillae not observable.

Notogaster . Anterior notogastral margin convex. All notogastral setae (p 1: 19–22; c: 22–26; h 1, p 2, p 3: 26–30; la, h 3: 52–56; lm, h 2: 90–97; lp: 112–116) setiform, slightly barbed to well barbed; la located posterolateral to lm. Opisthonotal gland opening and lyrifissures ia, im, ip distinct; lyrifissures ih and ips not observable.

Gnathosoma. Subcapitulum size: 82–90 × 49–56; all subcapitular setae (22–26) setiform, slightly barbed; both adoral setae (7) setiform, smooth. Palp length: 52–56; setation: 0–2–1–3–9(+ω); solenidion long (3/4 of tarsus), slightly bacilliform, pressed to surface; postpalpal seta (7) spiniform, smooth. Chelicera length: 82–90; setae (cha: 24–26; chb: 15–17) setiform, barbed.

Epimeral and lateral podosomal regions. Epimeral formula: 3–1–3–3; all setae (1c: 13–15; 1a, 2a, 3a: 15–19; 1b, 3b, 4b: 19–26; 4a, 4c: 34–41; 3c: 45–56) setiform, slightly barbed. Discidium rounded.

Anogenital region. Anogenital formula: 6–1–2–3; all genital setae (9–11) setiform, roughened; aggenital (19–22), anal (15–19) and adanal (ad 1: 15–19; ad 2, ad 3: 19–22) setae setiform, slightly barbed. Adanal lyrifissure close and parallel to anal aperture.

Legs. Claw of each leg smooth. Trochanter III with several lateral and posterior teeth. Formulas of leg setation and solenidia: I (1–5–2–4–20) [1–2–2], II (1–5–2–4–16) [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; setae p’ and p” setiform on tarsus I versus short, conical (poorly observable) on tarsi II–IV; seta s eupathidial on tarsus I; seta pv” on tarsus IV modified, brush-like; solenidia ω 1 on tarsus I, ω 1, ω 2 on tarsus II, φ on tibia II, and σ on genu III medium-sized, slightly bacilliform; ω 2 on tarsus I and φ 2 on tibia I medium-sized, rodlike; other solenidia long, subflagellate.

Remarks. In having long, barbed branches of the bothridial seta and comparatively long dorsal notogastral setae, A. tetraramosa sp. nov. is similar to A. dechambrierorum ( Mahunka, 1983) from the Northern Neotropical region and A. serrulata ( Balogh & Mahunka, 1980) from the Northern Neotropical and Oriental regions. However, the new species can be distinguished from both by the morphology of the rostrum (median part rounded, shorter than lateral ones versus median part triangular, similar to lateral ones in length in A. dechambrierorum , triangular, longer than lateral ones in A. serrulata ), the length of dorsal notogastral setae (lm, lp and h 2 long, la and h 3 medium-sized versus lm, lp, h 2, la, and h 3 similar in length, medium-sized), the sculpturing of basal part of the prodorsum (densely tuberculate versus with some short longitudinal ridges in A. dechambrierorum and A. serrulata ), the length of the costula (completely developed versus mediobasal part of costula not observable in A. dechambrierorum and A. serrulata ), and the presence (versus absence in A. dechambrierorum and A. serrulata ) of the specific ridge-like structure in front of the transcostula.

In having specific ridge-like structure in front of the transcostula, A. tetraramosa sp. nov. is similar to W. cervifer from the Northern Neotropical region ( Mahunka 1983; see supplementary description below). However, the new species can be distinguished from the latter by the morphology of the bothridial seta (clavate, with four branches versus pectinate, with five branches in W. cervifer ), length of dorsal notogastral setae (lm, lp and h 2 distinctly longer than la and h 3 versus lm, lp, h 2, la, and h 3 similar in length), the sculpturing of basal part of the prodorsum (densely tuberculate versus with one pair of short longitudinal ridges in W. cervifer ), the length of the costula (completely developed versus mediobasal part of costulae not developed in W. cervifer ).

Etymology. The species name tetraramosa (“four” and “branch” in Latin) refers to the presence of four branches on the bothridial head.

Figures

Figures 1–4. Arcoppia tetraramosa sp. nov., adult (gnathosoma and legs omitted): 1—dorsal view; 2—ventral view; 3—right lateral view; 4—bothridial seta, lateral view. Scale bars 100 μm (1–3), 20 μm (4).

Figures 5–11. Arcoppia tetraramosa sp. nov., adult: 5—subcapitulum, ventral view; 6—palp, left, paraxial view; 7—chelicera, right, antiaxial view; 8—leg I, right, antiaxial view; 9—leg II, right, antiaxial view; 10—leg III, left, antiaxial view; 11—leg IV, left, antiaxial view. Scale bars 20 μm (5–7), 50 μm (8–11).