Sternoppia (Luisternoppia) subiasi, Miko, 2024

Miko, Ladislav, 2024, Oribatid mites (Acarina, Oribatida) from French Guyana III. A new subgenus and its type species, Sternoppia (Luisternoppia) subiasi sp. nov. from family Sternoppiidae Balogh et Mahunka, 1969, Zootaxa 5556 (1), pp. 200-204 : 201-204

Type species: Sternoppia (Luisternoppia) subiasi sp.nov.

Subgeneric diagnosis. With character states of Sternoppia Balogh & Mahunka, 1968 (also see Ermilov et al, 2022), with the following: Distinct transcostula present. Bothridial seta„dendritiform“, with well-developed fusiform head, ciliated distally with 5–6 long, mostly distally furcate or trifurcate cilia. Notogastral setae of l- and h- series long, reaching beyond the insertions of subsequent setae, insertions of lm clearly anteriomediad to insertions of la. In addition to epimeral seta 3a, also 4a strongly modified, penicillate to ramose, thick, with long and sharp ciliae or rami, directed anteriad. Similarly modified setae present on ventral side of tarsi II and III (seta pv, s, a, u).

Etymology. The subgeneric name prefix refers to given name of Luis Santos Subías.

Remarks. The presence of transcostula (or translamella) in higher oribatids is often used as a generic character and could probably justify establishing a separate genus within Sternoppiidae . The new species is however very similar in general morphology to species from the genus Sternoppia in most morphological characters, particularly in the development of the bothridial seta and ventral part of the body. As this is the first and single species with these distinctive characters, placement within Sternoppia as a separate subgenus is proposed. Further discovery of other species with these subgenus characters may eventually lead to its elevation to generic level.

Description of adult

( Figs 1 , 2 )

Measurements. Holotype body length: 335; notogaster length: 215; notogaster width: 228

Integument. Body color brown. Body surface smooth, lateral parts of prodorsum anterior and laterad to bothridium and between bothridium and acetabula I and II, as well as on lateral parts of epimeres I with fine and dense granulation. Lateral part of pedotectum I with reticulate pattern, dorsal part of podosoma above acetabula III and IV and discidium with larger flat tubercles, covered by granulation.

Prodorsum. Rostrum rounded or very slightly angulate. Costula well developed, with slightly arched proximal part, well developed postcostular tubercle and another subcostular cuticular thickening present around insertion of interlamellar seta, reaching bothridium. Bothridium quite small, with small postbothridial tubercle, another, large and elongated tubercle present anterolateral to bothridium. Transcostula present, well developed and quite broad, slightly concave flatly U-shaped, forming together with anterior part of costulae blunt ceratiform projections. Tectopedial field with distinctly thickened, costular border anteriad and anteriolaterad, with row of irregular sigillae laterad and anteriolaterad to costulae. Bothridial seta with well-developed fusiform head, ciliated distally with 5–6 long, mostly distally furcate or trifurcate cilia. Rostral (44), lamellar (62), and interlamellar (71) setae long, setiform, ro densely, in and le sparsely, shortly ciliate. Exobothridial seta (45) rectangularly bent, setiform.

Notogaster. Roughly circular, broader than its length. Ten pairs of notogastral setae, c (6) short setiform, setae of l- and h- series setiform, sparsely ciliate, very long (la 93; lm 87; lp 81; h 1 111; h 2 90; h 3 132), h 3 clearly the longest, all of them reaching distinctly beyond insertions of subsequent seta. Setae h distally attenuated and slightly flagelliform. Setae p much shorter (32–35), setiform, sparsely but distinctly ciliated. Seta lm inserted anteriomediad to la. Lyrifissure ia and im visible, quite long (6–12), other lyrifissures not observed.Two small round spots (diameter around 2) present, one posterolaterad to lp insertion, one anterolaterad to h 2.

Gnathosoma . Subcapitulum size 86 × 53; mentum length 33; rutellum distally broadened, hyaline, pointed anteriad. Subcapitular setae setiform, a (10) smooth, m (27) and h (34) with long, sparse ciliae, palp and chelicerae as in Sternoppia ( Ermilov et al. 2022) (not studied in detail due to limited material available).

Epimeral and lateral podosomal regions. Epimeral plates with complicated tecta, these tecta on epimere I and partly also epimere II overlapping, with distinct angular lobes anteriomediad, bearing insertion of seta 1a. Tecta from epimeres II and III not touching medially, surrounding slightly depressed anterogenital area and bearing distinct and modified epimeral setae 3a, tectum of epimere 4 framing epimeral posterior margin, well developed and distinct. Epimeral setae of various shapes and sizes. Setae 3a (33) strong, thickened, ramose with rami of different length, pointed mediad, directed against each-other. Setae 4a (27) strong, penicillate, standing close to each-other, parallel and oriented anteriad, inserted on thickened cuticular arch anterior to genital opening. Other epimeral setae long, setiform, sparsely but distinctly ciliated, seta 1a shorter (25), strongly bend and slightly thickened at the base; 1b longer (44), also with thickened proximal (basal) part. Other epimeral setae setiform and sparsely ciliated, 2a, 3b, 3c shorter (41–44) and 1c, 4b and 4c much longer (60, 66, and 54, respectively). Discidium rather large, dentiform.

Anogenital region. Genital opening (39 x 39) and anal opening (66 x 66) rather small, separated by broad strip of ventral plate. Genito-anal formula 6 g, 1 ag, 2 an, 3 ad. Genital setae (13–17) setiform, with 1–2 bristles distally. Anal setae (19–25) setiform, distinctly ciliated. Aggenital and adanal setae of similar length (31–36), setiform and ciliated, ad 3 strongly shifted laterad, distance ad 3 –ad 3 roughly 1,6 times more than distance ad 1 –ad 1. Lyrifissure iad (18–19) close and parallel to anal plate.

Legs. Leg setation and solenidia as in other Sternoppia ( Ermilov et al. 2022) , formulas: 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]. Famulus setiform, tarsal solenidia blunt, other setiform, proral setae on legs II-IV short, thorn-like, some ventral setae on tarsi I–III (u, a, s, pv“) modified, stronger, with long and acute cilia, penicillate. Seta v’ of trochanter I and II very long, setiform, densely ciliated. Remaining setae mostly setiform and ciliated. More detailed study of legs not performed due to limited material available.

Type material. Holotype and one damaged paratype (sex not studied) from South America , French Guyana, sample LM-2012-008: Montagne de Kaw, GSM 4°33’16.248”N, 52°10’18.061”W, near Auberge Camp Caiman , close to Reserve for Coq du Roche , 220 m above sea level. Tropical rainforest litter, dead leaves, and rotting wood on the soil surface, moist. March 10 th, 2012, Ladislav Miko lgt.

The holotype is deposited in the Acarological collection of the Senckenberg Museum in Gorlitz, Germany, paratype in collection of the author (Prague, Czech Republic).

Remarks. The new species differs from all known Sternoppia species by the presence of a transcostula (versus transcostula absent), very long notogastral setae (versus setae of notogaster relatively shorter) and specific form of bothridial seta.

Etymology. The species is named in honour of outstanding Spanish acarologist Luis Santos Subías, a reminder of his extensive work in taxonomy and biogeography of oribatid mites.

Key to subgenera of Sternoppia

A key to all other species is available in Ermilov et al. (2022)

1. Bothridial seta bacilliform, with slightly developed, not ciliated head; interbothridial region with two pairs of tubercles; adanal setae not ciliated; body length: 660–720................................. Sternoppia (Andoppia) Ermilov et al., 2022 ............................................................Monotypical, type species: S. (A.) tetratuberculata

- Bothridial seta setiform or slightly fusiform, unilaterally or distally ciliated; interbothridial region without or with one pair of tubercles; adanal setae ciliated.......................................................................... 2

2. Distinct transcostula present, costula anteriad with angular distal end. Notogastral setae very long, reaching clearly over insertions of following setae. Epimeral setae 3a and 4a modified, thick, penicillate or ramose, with long and dense rami and cilia............................................................... Sternoppia (Luisternoppia) subgen. nov..............................................................Monotypical, type species S. (L.) subiasi sp. nov.

- Transcostula absent, costula anteriorly without angular ends. Notogastral setae usually short and not reaching insertions of following seta, rarely one or few setal pairs long. None or only one pair of epimeral seta (either 3a or 4a) usually modified and strongly ciliated................................................... Sternoppia (s. str.) Balogh & Mahunka, 1968.................................................. 16 species, type species S. mirabilis Balogh & Mahunka, 1968

Figures

FIGURE 1. Sternoppia (Luisternoppia) subiasi sp. nov., adult (holotype). A—dorsal view; B—ventral view; C—detail of genital shield and setae (enlarged, not to scale). Scale bar indicating 100 µm.

FIGURE 2. Sternoppia (Luisternoppia) subiasi sp. nov., adult (holotype). A—infracapitulum; B—bothridial area with base of costulae, bothridial and interlamellar seta; C—selected epimeral setae; D—prodorsal setae; E—selected notogastral setae; F—tibia and tarsus of leg III. Scale bars indicating: 50 µm (bar near D for A, C, D, E), 50 µm (B), and 100 µm (F).