Tritegeus mitratus Ermilov 2024
Creators: name: Ermilov, Sergey G.
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Sarcoptiformes
Cepheusidae
Tritegeus
Tritegeus mitratus

description: Tritegeus mitratus (Aoki, 1967)
(Figs 5, 6)
Material. Three specimens (one male and two females): Japan, Shikoku, Ishizuchi Mountain National Park, Tsuchigoya, Mt. Kamegamori, 1650 m a.s.l., abies and moss litter, with fungi and moss 15.VIII.1980 (S. Peck).
All specimens (preserved in 70% solution of ethanol with a drop of glycerol) are deposited in the collection of the University of Tyumen, Museum of Zoology, Tyumen, Russia.
Supplementary description of adult. Measurements. Body length: 780–825; notogastral width: 550–600.
Integument (Figs 5A–C). Body color dark brown. Body and legs partially covered by thick gel-like layer of cerotegument, including dense microtubercles, larger near the U-shaped thickening on notogaster; lamella, epimere I, pedotecta I, II, discidium, lateral part of prodorsum partially foveate; lateral side of body between humeral process and acetabula II – IV with dense large tubercles; anogenital region with heavy ridges; marginal region of notogaster with some longitudinal ridges; additionally, humeral process, podosomal region and dorsal part of pedotectum I partially rugose.
Prodorsum (Figs 5A–C). Rostrum pointed, not observable in dorsal aspect. Rostral region with short transverse ridge. Lamellar cusps fused mediodistally on significant continuation (hence, translamella absent); outer tooth of lamellar cusp well developed. Tutorium with numerous teeth and small scales dorsally. Rostral seta (86–94) setiform, with short, flexible tip, barbed; lamellar seta (131–154) with thickened mediobasal part and flagellate distal part, with sparse barbs; interlamellar seta (176–195) thickened, acuminate, roughened; bothridial seta (90–94) with longer stalk and short expanded head bearing numerous strong spines; exobothridial seta (56–60) setiform, roughened.
Notogaster (Figs 5A–D). Centrodorsal region bordered by U-shaped thickening bearing dorsal notogastral setae. Setae h 1 (49–56) and p 1 (56–64) thickened, acuminate, heavily barbed; p 2, p 3 (34–41) slightly stiff, roughened; other setae (86–94) thickened, acuminate, roughened. Opisthonotal gland opening and all lyrifissures observable.
Gnathosoma (Figs 6A–C). Subcapitulum size: 146–157 × 105–112; subcapitular setae (a: 30–34; m: 19–22; h: 30–37) setiform, roughened; m thinnest; both adoral setae (17–19) setiform, smooth. Palp length: 82–86; postpalpal seta (11) spiniform, roughened. Chelicera length: 146–161; setae (cha: 34–37; chb: 26–30) setiform, barbed.
Epimeral and podosomal regions (Figs 5B, C). All epimeral setae (3c, 4c: 56–64; 1b: 37–45; 1c, 3b, 4a, 4b: 30; 1a, 2a, 3a: 11) setiform, roughened. Discidium large, elongate triangular, rounded distally.
Anogenital region (Figs 5B–D). Genital (g 1, g 2: 26–30; g 3: 22–26; others: 15–19), aggenital (22–26), anal (22– 26), and adanal (ad 1: 30–34; others: 26–30) setae setiform, roughened. Adanal lyrifissure distinct, oblique.
Legs (Figs 6D–G). All tarsi with three claws; median claw thicker than lateral claws; all claws slightly barbed on dorsal side. Trochanters III and IV with long tooth dorsoanteriorly. Formulas of leg setation and solenidia: I (1- 5-3-4-20) [1-2-2], II (1-4-3-4-16) [1-1-2], III (2-3-2-3-15) [1-1-0], IV (1-2-3-3-12) [0-1-0]; homology of setae and solenidia indicated in Table 1; comparison of morphology of some setae between T. mitratus, T. tridactylus and T. luissantossubiasi presented in Table 2.
Remarks. Based on the original description (Aoki 1967) and the data presented here, the following diagnostic traits for T. mitratus are proposed:
Adult. Body size: 780–840. Notogaster foveolate. Rostrum pointed. Lamellar cusps fused mediodistally (rostrum not observable in dorsal aspect). Rostral seta setiform, with short, flexible tip, barbed; lamellar seta with thickened mediobasal part and flagellate distal part, with sparse barbs; interlamellar seta thickened, acuminate, roughened; in˃le˃ro; bothridial seta with shortly expanded head bearing numerous strong spines. Centrodorsal region of notogaster bordered by U-shaped thickening. Notogastral setae h 1 and p 1 comparatively short (p 1 slightly longer than h 1) thickened, acuminate, heavily barbed; p 2, p 3 shortest, slightly stiff, roughened; other setae medium-sized, thickened, acuminate, roughened. All leg tarsi heterotridactylous; trochanters III and IV with long tooth dorsoanteriorly; seta pv’ on Ta I, II with ventral sparse spines; l” on Ti I, II setiform; v’ on Ti I, II setiform, with ventral sparse spines; l” on Ge I, II setiform.
description: Published as part of Ermilov, Sergey G., 2024, Taxonomic contribution to knowledge of the oribatid mite genus Tritegeus (Acari, Oribatida, Cepheusidae), pp. 37-50 in Zootaxa 5556 (1) on pages 46-48, DOI: 10.11646/zootaxa.5556.1.4, http://zenodo.org/record/14595292