Parabelbella rusfareastensis, Ermilov & Ryabinin, 2020

Ermilov, Sergey G. & Ryabinin, Nikolay A., 2020, Сontribution to the knowledge of Parabelbella (Acari, Oribatida, Damaeidae): description of two new species from Russia and the U. S. A., redescription of P. inaequipes (Banks, 1947) and a key to known species, Zootaxa 4860 (3), pp. 352-374 : 353-360

publication ID	https://doi.org/ 10.11646/zootaxa.4860.3.2
publication LSID	lsid:zoobank.org:pub:59EEE472-ADE2-4A25-8749-4AEB19619078
DOI	https://doi.org/10.5281/zenodo.4536362
persistent identifier	https://treatment.plazi.org/id/DD13FD06-FFA8-FFE8-FF69-B136FDF1FBF0
treatment provided by	Plazi
scientific name	Parabelbella rusfareastensis
status	sp. nov.

Treatment

Parabelbella rusfareastensis sp. nov.

( Figs 1–6 View FIGURE 1 View FIGURE 2 View FIGURE 3 View FIGURE 4 View FIGURE 5 View FIGURE 6 )

Material examined. Holotype (male) and five paratypes (one male and four females): Russia, Far East, Primorsky Krai, Botchinsky Reserve, Baza mountain , 400 m a.s.l., 48°14’45’’N, 139°25’19’’E, soil in forest with cedars and spruce at the Mulpa river , 21.VI.2007 (collected by A.Yu. Oleinikov). Eight paratypes (one male and seven females): Russia, Far East, Khabarovsky Krai, Verkhnebureinsky District , Bureinsky Reserve , 3 km from the Umalta- Makit River , 51°40’02’’N, 134°14’46’’E, soil in mountain spruce forest on the western slope, 25.V.2013 (collected by A.L. Antonov). GoogleMaps

Type deposition. The holotype is deposited in the collection of the SMNH; 13 paratypes are deposited in the collection of the TSUMZ. All specimens are preserved in ethanol with a drop of glycerol.

Diagnosis. Body size: 348–398 × 215–249. Propodolateral apophysis absent. One pair of prodorsobasal tubercles (Ba). Rostral and lamellar setae long, setiform, barbed. Interlamellar seta long, stiff, erect, barbed. Bothridial seta very long, flagellate, smooth. Dorsal notogastral setae long, stiff, elongate crescent, sparsely barbed, p 1 – p 3 short, thinner and less stiff, roughened. Setae c 1 directed posterolaterad. Distance c 1 – c 1 shorter than that of c 1 – c 2. Distance lm–lp little longer than that of la–lm and lp–h 3. Parastigmatic apophysis Sa thorn-like, Sp tubercle-like. Epimeral and median ventral tubercles absent. Two pairs of ventrosejugal tubercles present, simple. Discidium triangular. Epimeral and anogenital setae setiform, roughened, seta 3b inserted on Vp. Leg femur III with five setae.

Description. Measurements. Body length: 348 (holotype), 348–398 (13 paratypes); notogaster width: 215 (holotype), 215–249 (14 paratypes). No clear differences between males and females in body size.

Integument ( Figs 5 View FIGURE 5 A–D). Body color light brown. Surface of body and legs sculptured (microtuberculate), partially covered by layer of cerotegument, which is represented by tuberculate and bacillar (sometimes also filamentous) structures.

Prodorsum ( Figs 1A, C View FIGURE 1 ; 5A, C View FIGURE 5 ; 6A, B View FIGURE 6 ). Rostrum rounded. Prodorsal tectum and propodolateral apophysis absent. Anterobothridial ridge distinct. Median part of interbothridial region with some distinct muscle sigillae, which anteriorly are bordered by semi-oval carina. One pair of prodorsobasal tubercles (Ba) developed, simple. Rostral (49–53) and lamellar (61–65) setae setiform, barbed, directed anteromediad. Interlamellar seta (36–41) stiff, erect, barbed, directed posteriad. Bothridial seta (225–246) flagellate, smooth. Exobothridial seta (20–24) setiform, thin, slightly barbed.

Notogaster ( Figs 1 View FIGURE 1 A–C; 5A, C; 6A, C). Oval. Exuvial scalps absent in all specimens. Eleven pairs of notogastral setae of light color, stiff, elongate crescent, but posterior setae (p 1 – p 3) thinner and less stiff. Setae c 1, c 2, la, lm, lp, h 1 – h 3 (41–49) sparsely barbed, p 1 – p 3 (20–24) roughened. Dorsal notogastral setae inserted in two parallel rows, c 1 directed posterolaterad, other setae directed posteriad (c 2 sometimes posterolaterad). Mutual distance between setae c 1 – c 1 shorter than that of c 1 – c 2. Distance between insertions of seta lm–lp little longer than that of la–lm and lp–h 3. All notogastral lyrifissures, opisthonotal gland opening, circumgastric scissure and circumgastric sigillar band distinct.

Gnathosoma ( Figs 2 View FIGURE 2 A–C; 5B). Subcapitulum longer than wide (86–90 × 69–73). Three pairs of subcapitular setae (a, 24–38; m, 32–36; h, 28–32) setiform, slightly barbed. Two pairs of adoral setae (8–12) setiform, thin, roughened. Palp (77–82) with setation 0-2-1-3-9(+ω). Solenidion of palptarsus bacilliform, appressed to palptarsal surface. Postpalpal seta (6) spiniform, smooth. Chelicera (82–86) with two setiform setae, cha (24–28) barbed, chb (14–16) shortly ciliate unilaterally in mediodistal part. Trägårdh’s organ of chelicera elongate triangular.

Lateral podosomal and epimeral and regions ( Figs 1B, C View FIGURE 1 ; 5B, C View FIGURE 5 ; 6A, D, E View FIGURE 6 ). Parastigmatic apophysis Sa thornlike, elongate triangular, Sp tubercle-like. Both pairs of epimeral tubercles and one pair of median tubercles absent. Two pairs of ventrosejugal tubercles present, simple. Discidium triangular. Epimere I with small median hollow (ring-like internal structure in light microscope). Epimeral setal formula 3-1-3-4. Epimeral setae (1a, 2a, 3a, 4a, 4b, 20–24; 1b, 1c, 3b, 4c, 4d, 24–28; 3c, 41–45) setiform, roughened, seta 3b inserted on ventrosejugal tubercle Vp.

Anogenital region ( Figs 1B, C View FIGURE 1 ; 5B, C View FIGURE 5 ; 6A View FIGURE 6 ). Six pairs of genital (g 1, 24–28; g 2 – g 6, 20–24), one pair of aggenital (20–24), two pairs of anal (20–24) and three pairs of adanal (20–24) setae setiform, roughened. Adanal lyrifissure diagonal, located close to anal plate. Adanal seta ad 3 located posteriorly to adanal lyrifissure. Ovipositor typical for Damaeidae ( Ermilov 2010) , broad, slightly elongated (length 56, width of cylindrical part 45), blade (20) shorter than length of distal section (beyond middle fold; 36). Each of the three blades with four smooth thorn-like setae (8–10) thorn-like. Six coronal setae thorn-like (6).

Legs ( Figs 3A, B View FIGURE 3 ; 4A, B View FIGURE 4 ; 5 View FIGURE 5 A–C; 6A). Leg I similar to body in length approximately, legs II and III shorter than body length, leg IV longer than body length ( Table 1 View TABLE 1 ). Claw of all legs comparatively small, thin, smooth. Dorsoparaxial porose area on femora I–IV and on trochanters III and IV well visible. Formulas of leg setation and solenidia: I (1-7-4-4-20) [1-2-2], II (1-6-4-4-17) [1-1-2], III (2-5-3-3-17) [1-1-0], IV (1-4-3-3-14) [0-1-0]; homologies of setae and solenidia indicated in Table 2. Solenidion and coupled seta on genua I-III similar in length approximately.

Note: Roman letters refer to normal setae, Greek letters to solenidia (except ɛ = famulus), d σ and d φ – seta and solenidion coupled. * – seta v” present in P. rusfareastensis (versus absent in P. pseudoinaequipes and P. inaequipes )

Etymology. The specific name rusfareastensis refers to the place of origin (Russian Far East).

Remarks. Parabelbella rusfareastensis sp. nov. is morphologically most similar to Parabelbella crenatosetosa Bulanova-Zachvatkina, 1967 in the presence of prodorsobasal tubercles Ba and stiff, bent dorsal notogastral setae, but it differs from the latter by the smaller body size (348–398 × 215–249 versus 640 × 400), the absence of propodolateral apophysis (versus small perpendicular propodolateral apophysis present), the direction of notogastral seta c 1 (posterolaterad versus anteriad), and the mutual distance between setae c (c 1 – c 1 distinctly shorter than that of c 1 – c 2 versus c 1 – c 1 about the same as c 1 – c 2).