Bathyscidius mikati ( Udržal, 1995 ), Čeplík & Lakota & Čeplík, 2021

Čeplík, Dávid, Lakota, Ján & Čeplík, Jaroslav, 2021, Bathyscidius mikati (Udržal, 1995), a new combination from the genus Bathyscia Schiødte, 1848 (Insecta, Coleoptera, Leiodidae, Cholevinae, Leptodirini), Zootaxa 4981 (1), pp. 166-176 : 167-174

Bathyscidius mikati ( Udržal, 1995)

( Figs 1–10 )

Bathyscia mikati Udržal, 1995: 25 , new combination.

Bathyscia mikati Udržal : Perreau, 2000: 168.

Laneyriella mikati Udržal : Perreau, 2015: 217; Hlaváč et al. 2017: 113.

Material studied. Holotype, ♂: „ Monte Negro , Adriatic Coast, 25 km SE Budva, Sutomore, 0–400 m, 20.05.1988, leafy forest, sifting, M. Mikát lgt.“ (white, printed); „ HOLOTYPE Bathyscia mikati sp. n., R. Udržal det., 1994“ (red, printed), ( CNHM) [The holotype has the aedeagus placed in the lateral position and preserved in an unknown substance] . Paratype: 1♀ same data as for the holotype, ( CJL) [The specimen is lacking genitalia] ;

Other material. 1 ♂, 1 ♀: „ Montenegro, Rumija Mts. , Phoenix pit, 07.08.2005, sifting at – 50 m, R. Mlejnek lgt“ (white, printed), ( CDC, CJL) ; 3 ♂♂, 2 ♀♀: „ Montenegro, Rumija Mts. , Little Virgin pit, 05.08.2005, sifting close to the entrance, R. Mlejnek lgt“ (white, printed), ( CDC, CJL) ; 1 ♀: „ Montenegro, Rumija Mts. , Ice Virgin pit, 05.08.2005, sifting at – 25 m, R. Mlejnek lgt“ (white, printed), ( CJL) ; 6 ♂♂, 8 ♀♀, 1 specimen sex not determined: „ Montenegro, Rumija Mts. , 1100–1200 m a.s.l., sifting in sink holes overgrown with beech forest, 18.05.2005, R. Mlejnek lgt“ (white, printed), ( CDC, CJL, CPH, CJC) .

Note: Most of specimens are not in good condition, various appendeges or body parts are missing.

Redescription. Body small, bathyscioid ( Figs 2 , 4 ), elliptically elongate, convex, weakly pigmented, with fine pubescence, colour from yellowish–brown to reddish–brown. BL: 1.75–1.99 mm, L: 1.37–1.55 mm.

Head ( Fig. 1 ) approximately as long as wide (due to the measuring technique of the head capable of being retracted), HL1: 0.29–0.37 mm, HL2: 0.38–0.44 mm, HW: 0.38–0.44 mm, eyes completely absent, with posterior neck region and genae more or less glabrous. Transverse occipital crest present but weakly–defined. Clypeus subhexagonal, frontoclypeus and labrum densely setose. Mandibles short, robust, with proximal and subapical incisors and one or two small teeth between. Terminal maxillary palpomere conical, pointed apically, slender and much shorter than the thick penultimate palpomere. Antennae (AL: 0.59–0.67 mm), finely pubescent ( Figs 3a–3b ), inserted approximately in middle of median third of head. Pedicel about 1.6 times as long as scape. Antennomere 3 longer than antennomere 4–6. Antennomere 7 longer and larger than 6, with Hamman organ developed. Antennomeres 8–10 approximately as long as wide. Antennomere 11 longest or as long as pedicel, approximately 1.9 times longer than wide, dorso–ventrally flattened. Relative length of antennomeres (male, AL: 0.59 mm): (1) 0.06, (2) 0.10, (3) 0.06, (4) 0.04, (5) 0.04, (6) 0.04, (7) 0.05, (8) 0.04, (9) 0.05, (10) 0.05 and (11) 0.11. Relative width of antennomeres (male, AL: 0.59 mm): (1) 0.04, (2) 0.03, (3) 0.02, (4) 0.02, (5) 0.02, (6) 0.02, (7) 0.04, (8) 0.04, (9) 0.05, (10) 0.05 and (11) 0.05. Antennomere length/width ratios (male, AL: 0.59 mm): (1) 1.50, (2) 3.33, (3) 3.00, (4) 2.00, (5) 2.00, (6) 2.00, (7) 1.25, (8) 1.00, (9) 1.00, (10) 1.00 and (11) 2.20. Relative length of antennomeres (female, AL: 0.67 mm): (1) 0.07, (2) 0.11, (3) 0.06, (4) 0.04, (5) 0.05, (6) 0.04, (7) 0.06, (8) 0.04, (9) 0.05, (10) 0.05 and (11) 0.10. Relative width of antennomeres (female, AL: 0.67 mm): (1) 0.04, (2) 0.04, (3) 0.02, (4) 0.02, (5) 0.02, (6) 0.02, (7) 0.03, (8) 0.03, (9) 0.05, (10) 0.05 and (11) 0.06. Antennomere length/width ratios (female, AL: 0.67 mm): (1) 1.75, (2) 2.75, (3) 3.00, (4) 2.00, (5) 2.50, (6) 2.00, (7) 2.00, (8) 1.33, (9) 1.00, (10) 1.00 and (11) 1.66.

Pronotum ( Fig. 2 ) strongly convex, wider than long (PL/PW: 0.62), lateral edges evenly rounded, widest at posterior margin. PL: 0.44–0.56 mm. PW: 0.71–0.89 mm. Dorsal surface pubescent, pubescence short, more or less recumbent. Prosternal ventral surface almost glabrous.

Elytra ( Fig. 4 , right elytron) elongate oval, pubescent, maximum width in anterior half, longitudinal parasutural striae absent. EL: 0.92–1.04 mm. EW: 0.71–0.89 mm. EL/EW: 1.16–1.29. Punctation relatively dense, consisting of small shallow punctures, weak punctation and pubescence on apical and median part of the disc near the elytral suture. Pubescence is aligned in transverse striae which are missing on apical part. Scutellum triangular, more or less pubescent.

Venter. Mesoventral surface almost glabrous, metaventral more or less pubescent. Mesocoxal cavities separated, mesoventral process well–developed. Metacoxae separated by bifid metaventral posterior process. Median longitudinal carina (=mesoventral carina, Fig. 5 ), well–developed, elevated, moderately thick, not lamellar, flattened on ventral edge, with recumbent and backwardly oriented setae. Carina extendeding over metaventrite, sharp posterior beak reaching bifid metaventral posterior process. Sternites pubescent with short and fine setae.

Legs short and robust. Protarsi with four slender, undilated tarsomeres in both sexes, first protarsomere slightly longer than second and third, fourth longest. Mesotarsi and metatarsi pentamerous in both sexes. Claws well developed and sharp, empodium with one bifurcate seta. Protibiae flattened, armed with spines ( Fig. 6 ), on external lateral and apical side with row of flattened spines forming comb (pecten) reaching approximately apical half of protibial length, internal subapical side with one shorter and one longer subapical multi–toothed spurs. Mesotibiae and metatibiae armed with lateral spines, with apical crown of spines of unequal length ( Gnaspini et al. 2020) and two internal apical multi–toothed spurs. Femora surface reticulated.

Genitalia. Aedeagus ( Fig. 10 ) small, elongate, 0.40–0.41 mm long, maximum width of median lobe 0.05 mm, length of basal lamina 0.08 mm, maximum width of basal lamina 0.08 mm. Median lobe from dorsal aspect almost straight, distinctly tapered towards rounded obtuse apex which is longer than parameres. Median lobe more or less straight in lateral aspect, only slightly curved on mid–length. Basal lamina lacking posterior expansion. Parameres parallel–sided, shorter than median lobe, more or less straight and elongate, distinctly narrowed towards pointed apex which bears two apical and one lateral setae. Female ventrite VIII pubescent in basal part with anterior expansion stout ( Fig. 8 ). Each style ( Fig. 7 ) with five setae, stylus cylindrical, with one long seta. Spermatheca ( Fig. 9 ).

Sexual dimorphism: Not apparent.

Differential diagnosis. Bathyscidius mikati differs from all other species of the genus by possessing five setae on each style versus four setae on each style in other species. The distinct protibial external latero–apical comb (pecten) extending to approximately apical half of the protibial length in Bathyscidius mikati seems to be an intermediate character state within the genus versus distinct protibial external latero–apical comb (pecten) extending to approximately two apical thirds of the protibial length in Bathyscidius (s. str.), and versus either less distinct protibial external latero–apical comb (pecten) extending to approximately apical third of the protibial length in B. (Ionobathyscidius) rambouseki and in B. (I.) tomoricensis or similar distinct protibial external latero–apical comb (pecten) extending to approximately apical half of the protibial length in B. (I.) basarai .

Due to the similarity of the median lobe whith obtuse, simple rounded apex and each paramere with two subapical and one lateral setae Bathyscidius mikati is tentatively assigned to the subgenus Bathyscidius . The species of Bathyscidius (s.str.) can be separated from Bathyscidius mikati as follows:

• B. fallaciosus by: AL: 0.57–0.60 mm versus 0.59–0.67 mm in Bathyscidius mikati ; aedeagus length 0.32 mm versus 0.40–0.41 mm in Bathyscidius mikati ; basal lamina maximum width 0.05 mm versus 0.08 in Bathyscidius mikati ; antennomere (1–11) length/width ratios: (1) 1.97–1.95, (2) 2.73–3.02, (3) 1.93–2.24, (4) 1.35–1.55, (5) 1.37–1.52, (6) 1.20–1.31, (7) 1.28–1.36, (8) 0.77–0.79, (9) 0.86–0.92, (10) 0.85–0.87 and (11) 1.60–1.76 versus (1) 1.50–1.75, (2) 2.75–3.33, (3) 3.00, (4) 2.00, (5) 2.00–2.50, (6) 2.00, (7) 1.25–2.00, (8) 1.00–1.33, (9) 1.00, (10) 1.00 and (11) 1.66–2.20 in Bathyscidius mikati .

• B. komajiensis by: AL: 0.70–0.76 mm versus 0.59–0.67 mm in Bathyscidius mikati ; aedeagus length 0.28– 0.30 mm versus 0.40–0.41 mm in Bathyscidius mikati ; antennomere (1–11) length/width ratios: (1) 1.98–2.16, (2) 3.32–3.70, (3) 3.02–3.18, (4) 2.17–2.22, (5) 2.16–2.65, (6) 1.63–1.76, (7) 1.68–1.92, (8) 1.16–1.29, (9) 1.23, (10) 1.08–1.10 and (11) 1.92–2.02 versus (1) 1.50–1.75, (2) 2.75–3.33, (3) 3.00, (4) 2.00, (5) 2.00–2.50, (6) 2.00, (7) 1.25–2.00, (8) 1.00–1.33, (9) 1.00, (10) 1.00 and (11) 1.66–2.20 in Bathyscidius mikati .

• B. mljetensis by: AL: 0.51–0.59 mm versus 0.59–0.67 mm in Bathyscidius mikati ; aedeagus length 0.30– 0.34 mm versus 0.40–0.41 mm in Bathyscidius mikati ; antennomere (1–11) length/width ratios: (1) 1.85–1.89, (2) 2.82–2.97, (3) 2.10–2.30, (4) 1.47–1.62, (5) 1.41–1.54, (6) 1.15–1.27, (7) 1.15–1.33, (8) 0.77, (9) 0.78–0.83, (10) 0.69–0.75 and (11) 1.50–1.62 versus (1) 1.50–1.75, (2) 2.75–3.33, (3) 3.00, (4) 2.00, (5) 2.00–2.50, (6) 2.00, (7) 1.25–2.00, (8) 1.00–1.33, (9) 1.00, (10) 1.00 and (11) 1.66–2.20 in Bathyscidius mikati .

• B. orjensis by: AL: 0.49–0.54 mm versus 0.59–0.67 mm in Bathyscidius mikati ; median lobe maximum width 0.06–0.08 mm versus 0.05 mm in Bathyscidius mikati ; basal lamina maximum width 0.09–0.13 mm versus 0.08 mm in Bathyscidius mikati ; basal lamina length 0.11–0.15 mm versus 0.08 mm in Bathyscidius mikati ; antennomere (1–11) length/width ratios: (1) 1.65–1.76, (2) 2.65, (3) 2.05–2.32, (4) 1.44–1.54, (5) 1.33–1.44, (6) 1.13–1.15, (7) 1.09–1.21, (8) 0.69–0.74, (9) 0.74–0.85, (10) 0.74–0.79 and (11) 1.50–1.55 versus (1) 1.50–1.75, (2) 2.75–3.33, (3) 3.00, (4) 2.00, (5) 2.00–2.50, (6) 2.00, (7) 1.25–2.00, (8) 1.00–1.33, (9) 1.00, (10) 1.00 and (11) 1.66–2.20 in Bathyscidius mikati .

• B. tristiculus by: aedeagus length 0.31–0.35 mm versus 0.40–0.41 mm in Bathyscidius mikati ; antennomere (1–11) length/width ratios: (1) 1.97–2.00, (2) 3.05–3.09, (3) 2.69–2.94, (4) 1.73–1.78, (5) 1.66 –1.72, (6) 1.30–1.32, (7) 1.39–1.47, (8) 1.02–1.27, (9) 0.94–1.08, (10) 0.78–1.02 and (11) 1.58–1.82 versus (1) 1.50–1.75, (2) 2.75–3.33, (3) 3.00, (4) 2.00, (5) 2.00–2.50, (6) 2.00, (7) 1.25–2.00, (8) 1.00–1.33, (9) 1.00, (10) 1.00 and (11) 1.66–2.20 in Bathyscidius mikati .

The additional comparison with the subgenus Ionobathyscidius .

The species of Bathyscidius (Ionobathycidius) can be separated from Bathyscidius mikati as follows:

• B. basarai by: EL/EW: 1.07–1.12 versus 1.16–1.29 in Bathyscidius mikati ; a posterior beak of shorter median longitudinal carina (=mesoventral carina) not reaching the bifid metaventral posterior process versus longer mesoventral carina with posterior beak reaching the bifid metaventral posterior process in Bathyscidius mikati ; median lobe with a pointed beak–shaped apex versus median lobe apex simple rounded in Bathyscidius mikati ; median lobe with some lateral longitudinal lobes versus median lobe without lateral longitudinal lobes in Bathyscidius mikati ; each paramere bears three subapical setae versus two subapical and one lateral setae in Bathyscidius mikati ; antennomere (1–11) length/width ratios: (1) 2.00–2.33, (2) 3.33, (3) 2.00–2.50, (4) 1.50, (5) 1.33, (6) 1.00, (7) 1.50–1.66, (8) 0.66–0.75, (9) 0.75–0.80, (10) 1.00 and (11) 1.83–2.00 versus (1) 1.50–1.75, (2) 2.75–3.33, (3) 3.00, (4) 2.00, (5) 2.00–2.50, (6) 2.00, (7) 1.25–2.00, (8) 1.00–1.33, (9) 1.00, (10) 1.00 and (11) 1.66–2.20 in Bathyscidius mikati .

• B. rambouseki by: AL: 0.55–0.57 mm versus 0.59–0.67 mm in Bathyscidius mikati ; a more or less pointed apex of the median lobe versus median lobe apex simple rounded in Bathyscidius mikati ; median lobe with some lateral longitudinal lobes versus without lateral longitudinal lobes in Bathyscidius mikati ; each paramere bears three subapical setae versus two subapical and one lateral setae in Bathyscidius mikati ; basal lamina length 0.09–0.12 mm versus 0.08 mm in Bathyscidius mikati ; antennomere (1–11) length/width ratios: (1) 1.55–1.73, (2) 2.65–2.82, (3) 2.22, (4) 1.88, (5) 1.67–1.84, (6) 1.25–1.31, (7) 1.29–1.40, (8) 0.75–0.87, (9) 0.87–0.96, (10) 0.82–0.92 and (11) 1.53–1.96 versus (1) 1.50–1.75, (2) 2.75–3.33, (3) 3.00, (4) 2.00, (5) 2.00–2.50, (6) 2.00, (7) 1.25–2.00, (8) 1.00–1.33, (9) 1.00, (10) 1.00 and (11) 1.66–2.20 in Bathyscidius mikati .

• B. tomoricensis by: AL: 0.56–0.59 mm versus 0.59–0.67 mm in Bathyscidius mikati ; a pointed apex of the median lobe versus median lobe apex simple rounded in Bathyscidius mikati ; each paramere bears three subapical setae versus two subapical and one lateral setae in Bathyscidius mikati ; basal lamina length 0.14 mm versus 0.08 mm in Bathyscidius mikati ; antennomere (1–11) length/width ratios: (1) 1.62–1.96, (2) 2.95–3.10, (3) 2.10–2.19, (4) 1.66–1.69, (5) 1.69–1.78, (6) 1.28–1.35, (7) 1.32, (8) 0.57–0.68, (9) 0.75–0.79, (10) 0.73–0.77 and (11) 1.51–1.74 versus (1) 1.50–1.75, (2) 2.75–3.33, (3) 3.00, (4) 2.00, (5) 2.00–2.50, (6) 2.00, (7) 1.25–2.00, (8) 1.00–1.33, (9) 1.00, (10) 1.00 and (11) 1.66–2.20 in Bathyscidius mikati .

Distribution and data. Bathyscidius mikati except its type locality is known from the Phoenix pit, at the elevation of approximately 1100 m a.s.l., from nearby Little Virgin pit, Ice Virgin pit and also from sifting in sink holes overgrown with beech forest at the elevation of 1100–1200 m a.s.l. in Rumija Mts., in southeastern Montenegro. The Phoenix pit was described in Lohaj et al. 2016. The species probably inhabits the wide subteranean habitat located in Rumija Mts. (caves–pits and MSS–superficial subterranean habitat, the known hypogean environment constituted by a network of interstices generally formed by fragmentation of the bedrock and accumulation of debris).

Reasons supporting the placement of Bathyscia mikati inside Bathyscidius :

• The mesoventral carina in the genus Bathyscia is not extendeding over the metaventrite ( Casale et al. 1990) versus mesoventral carina extendeding over the metaventrite with a sharp posterior beak reaching or not the bifid metaventral posterior process in the genus Bathyscidius ( Polak & Jalžić, 2019; D. Čeplík et al. 2021).

• The genus Bathyscia is lacking protibial comb (pecten) along the lateral external margin versus protibiae with an incomplete comb (pecten) along the lateral external margin in the genus Bathyscidius .

• Bathyscia mikati was listed ( Perreau, 2015; Hlaváč et al. 2017) inside the genus Laneyriella Guéorguiev, 1976 , which belongs to the subtribe Leptodirina . Genera from this subtribe have five protarsal segments in males. In the case of the genus Laneyriella , the first three male protarsal segments are distinctly dilated. Therefore the species can not be classified in the genus Laneyriella .

Figures

FIGURE 10. Bathyscidius mikati, aedeagus, dorsal aspect, scale bar 0.40 mm.

FIGURES 1–2. Bathyscidius mikati. 1: Head, dorsal aspect, scale bar 0.44 mm. 2: Pronotum, dorsal aspect, scale bar 0.89 mm.

FIGURES 3–5. Bathyscidius mikati. 3: Antennae, dorsal aspect, male antenna (3a), scale bar 0.11 mm, female antenna (3b), scale bar 0.10 mm. 4: Right elytron, dorsal aspect, scale bar 1.04 mm. 5: Venter, median longitudinal carina in metaventrite, scale bar 0.38 mm.

FIGURES 6–9. Bathyscidius mikati. 6: Male right protibia, dorsal aspect, scale bar 0.25 mm. 7: Styles, dorsal aspect, scale bar 0.10 mm. 8: Female ventrite VIII, dorsal aspect, scale bar 0.29 mm. 9: Spermatheca, dorsal aspect, scale bar 0.10 mm.