Speoplanes biocovensis bosnicus Vrbica, Vesović, Rađa & Ćurčić, 2024

Vrbica, Maja, Vesović, Nikola, Rađa, Tonći & Ćurčić, Srećko, 2024, A new subspecies of the subterranean beetle Speoplanes biocovensis Müller, 1934 (Coleoptera: Leiodidae: Cholevinae: Leptodirini) from Bosnia and Herzegovina: the first occurrence of the genus outside Croatia, Zootaxa 5405 (3), pp. 422-432 : 425-430

Speoplanes biocovensis bosnicus Vrbica, Vesović, Rađa & Ćurčić , ssp. n.

( Figs. 3–6 )

Material examined. Holotype male labeled as follows: “ Golubinka na Bubalove Njive Pit , 43 ° 08’03.5’’ N, 17 ° 34’27.4’’ E, 66 m a.s.l., Bijača settlement, near the town of Ljubuški, southern Bosnia and Herzegovina, 20.IV.2019 (hand collection), leg. Tonći Rađa ” (white label, printed) / Holotypus Speoplanes biocovensis bosnicus Vrbica, Vesović, Rađa & Ćurčić , ssp. n. Ćurčić det. 2023 (red label, printed) ( IZFB) ( Fig. 3A ) . Paratypes: two males and seven females, same data as for holotype ( IZFB) ; one male and three females, same locality as for holotype, 12.V.2019 (pitfall trapping with rotten meat or cheese as bait), leg. Tonći Rađa ( IZFB) ( Fig. 3B ). All paratypes are labeled with white, printed locality labels and with red printed labels “Paratypus Speoplanes biocovensis bosnicus Vrbica, Vesović, Rađa & Ćurčić , ssp. n. Ćurčić det. 2023” .

Description. Large-sized leptodirine. TL M 8.32 mm (8.39 mm in males, 8.29 mm in females), R 8.03–8.60 mm (8.21–8.60 mm in males, 8.03–8.60 mm in females) ( Table 1 ).

Habitus. Body elongate, elliptical, reddish-brown in colour ( Fig. 3 ).

Integument. Dull, barely pubescent, smooth on elytra, punctate on head and pronotum, with well-defined microsculpture ( Fig. 4 ). Sparsely distributed yellow erect pubescence of medium length on pronotum, elytra and part of head (frons, vertex and neck). Dense yellow recumbent pubescence only on rest of head (clypeus and genae).

Head. Longer than broad (HL/HW M 1.17, R 1.10–1.22), not narrowed at neck level, without occipital carina ( Figs. 4A and D ). Labrum slightly emarginate, with several long setae. Penultimate maxillary palpomere widened apically. Ultimate maxillary palpomere short, thin, gradually narrowing apically. Vertex with an impression. Antennae inserted shortly behind middle of head, slender, narrow, longer than body in males and females (AL/TL M 1.08, R 1.03–1.16), longer in males than in females (AL/TL M 1.14, R 1.11–1.16 in males; M 1.05, R 1.03–1.09 in females), AL M 8.98 mm (9.54 mm in males, 8.71 mm in females), R 8.38–10.03 mm (9.20–10.03 mm in males, 8.38–9.38 mm in females) ( Fig. 3 ). Antennomere I short, narrow proximately, widening towards apex. Antennomere II narrow, elongate, slightly widened distally, significantly longer than antennomere I (A1L/A2L M 0.62, R 0.54– 0.68). Antennomeres II, III, and VIII of similar shape and size, narrow, slightly widened distally. Antennomeres IX and X slightly dilated distally. Antennomere I shortest (M 0.44 mm, R 0.41–0.52 mm), while antennomere V (M 1.03 mm, R 0.93–1.15 mm) longest in both sexes. Antennomere VIII relatively short and narrow, longer in males than in females (M 0.81 mm, R 0.76–0.88 mm in males; M 0.69 mm, R 0.65–0.75 mm in females), shorter and narrower than antennomeres VII and IX–XI. Ultimate antennomere slender, widening sub-distally, then narrowing apically, narrower than penultimate or as wide as it (A11W/A10W M 0.89, R 0.76–1.00). Other ratios of length of certain antennomeres: A3L/A2L M 1.04, R 0.97–1.11. A3L/A4L M 0.79, R 0.74–0.87. A6L/A3L M 1.23, R 1.15–1.30. A8L/A3L M 0.98, R 0.92–1.11. A11L/A8L M 1.13, R 0.99–1.22 ( Table 1 ).

Prothorax. Pronotum sub-bell-shaped, about as long as broad, PL/PW M 0.99, R 0.95–1.03 (M 1.00, R 0.99– 1.02, in males; M 0.99, R 0.95–1.03 in females). PL/HL M 1.24, R 1.16–1.29. Lateral margins S-shaped. Widest at posterior angles in males and slightly anterior to middle in females, wider than head (HW/PW M 0.69, R 0.64–0.73) ( Figs. 3 , 4B and E ). Pronotal base almost straight. PB/AM M 1.45, R 1.34–1.51 (M 1.45, R 1.41–1.51 in males; M 1.44, R 1.34–1.51 in females) ( Table 1 ). Anterior margin barely convex medially. Anterior pronotal angles distinct, acute, pointed. Posterior pronotal angles slightly acute, almost right, not protruding posteriorly ( Figs. 4B and E ). Pronotal disc moderately convex.

Mesothorax. Mesoventral carina high anteriorly, low posteriorly ( Fig. 5 ). Anterior margin slightly concave, while posterior margin almost straight, with some setae. Tooth prominent, of variable shape (acute/right/obtuseangled), rounded. No mesoventral processus on mesoventrite ( Fig. 5 ). Scutellum large, triangular ( Figs. 4B and E ).

Metathorax. Metasternum without carina.

Elytra. Elongate, oval, broader in females than in males, EL/EW M 1.93, R 1.78–2.09 (M 2.04, R 2.00– 2.09 in males; M 1.88, R 1.78–2.01 in females), distinctly wider than pronotum, especially in females, EW/PW M 1.66, R 1.54–1.76 (M 1.57, R 1.54–1.59 in males; M 1.71, R 1.64–1.76 in females) ( Table 1 ) ( Figs. 3 , 4C and F ). Maximum width of elytra slightly in front of middle. Lateral margins arcuate. Shoulders weakly pronounced, obtuse, covered by posterior pronotal angles. Marginal furrows not visible from above. Elytral disc distinctly convex, in lateral view steeply sloping both basally and apically. Parasutural stria absent. Elytral apex slightly scaphoid. Pygidium covered by elytra.

Legs. Elongate and slender ( Fig. 3 ). Femora widened basally, narrowed in distal half. Tibiae thin, slightly curved, gradually widening distally. Each anterior tibia has a reduced distal brush-like structure. Female protarsi four-segmented. Male protarsi five-segmented, with first three segments clearly widened and flattened. Tarsal claws elongate, narrow, curved, apically pointed.

Male genitalia. Aedeagus large, elongate, straight, sclerotized ( Figs. 6A and B ). Basal bulb small and rounded in dorsal view ( Fig. 6A ), while moderately large in lateral view ( Fig. 6B ). Median lobe in dorsal view straight, subparallel, slightly tapering from middle to apex, rounded anteriorly, slightly bilobed at apex, slightly shorter than parameres ( Fig. 6A ). Median lobe curved in lateral view, concave dorsally around middle, with pointed apex, bent downwards sub-apically, slightly bent upwards apically ( Fig. 6B ). Parameres slender, narrow, arcuate, each with moderately widened rounded apex in dorsal view ( Fig. 6A ), while in lateral view they slightly narrow distally ( Fig. 6B ). Each paramere with three setae: one short apical, one short sub-apical and one longer sub-apical. Distance between apical seta and longer sub-apical seta greater than that between apical seta and shorter sub-apical seta. Longer sub-apical seta lies slightly below shorter sub-apical seta. Sclerites of inner sac thin and straight in both lateral and dorsal view ( Figs. 6A and B ).

Female genitalia. Gonostyli slender, thin, gradually narrowing distally, straight, apically pointed ( Fig. 6C ). Each gonostylus with one apical seta, three inner setae and one outer seta. Outer seta located at level between two inner setae. Spermatheca short, chitinized, basally slightly curved, almost straight and strongly constricted in middle, where somewhat less sclerotized, apically spherical ( Fig. 6D ).

Female abdominal sternite VIII. Large, transverse, hairy, with short and thin anterior process ( Fig. 6E ).

Diagnosis. The new subspecies is closely related to two other congeners, of which it is morphologically more similar to S. biocovensis biocovensis due to the shape of the sclerites of the inner sac (thin and straight) and the apex of the median lobe (flattened), as well as shorter legs and antennae and smaller AL/TL ( Table 1 ) ( Müller 1911, 1934; Jeannel 1924; Mizerakis et al. 2022).

Specimens of S. biocovensis bosnicus ssp. n. differ from S. biocovensis biocovensis in the size of the pro- and metatibiae in females (protibiae shorter than head and pronotum together, metatibiae shorter than elytra vs. protibiae as long as head and pronotum together, metatibiae as long as elytra), PL/PW (pronotum on average as long as wide vs. pronotum on average slightly longer than wide), position of maximum width of pronotum in females (slightly anterior to the middle vs. at the posterior angles), shape of mesoventral carina (less pronounced, with a more prominent tooth vs. more pronounced, with a less prominent tooth), and EL/EW in males (elytra less elongate vs. elytra more elongate). We also found that antennae in S. biocovensis bosnicus ssp. n. are on average shorter than in the nominotypic subspecies, and that antennomere VIII in the new subspecies is on average slightly shorter than antennomere III (antennomere VIII is on average slightly longer than antennomere III in S. biocovensis biocovensis ), antennomere XI in the new subspecies is on average longer than antennomere VIII (antennomeres XI and VIII are of similar length in S. biocovensis biocovensis ) and the pronotum in the new subspecies is on average about a quarter longer than the head (the pronotum in S. biocovensis biocovensis is on average about a third longer than the head) ( Table 1 and Fig. 2B ) ( Müller 1911, 1934; Mizerakis et al. 2022).

Specimens of S. biocovensis bosnicus ssp. n. differ from S. giganteus by the larger size (TL R 8.03–8.60 mm vs. 7.47–8.03 mm), HL/HW (1.10–1.22 vs. cca. 1.50), shorter antennae (AL R 8.38–10.03 mm vs. 10.42–11.15 mm), smaller AL/TL (R 1.03–1.16 vs. 1.30–1.32), A3L/A2L (0.97–1.11 vs. 1.14–1.20), A11L/A8L (0.99–1.22 vs. 0.87–0.96), size of pro- and metatibiae in females (protibiae shorter than head and pronotum together, metatibiae shorter than elytra vs. protibiae longer than head and pronotum together, metatibiae longer than elytra), PL/PW (pronotum as long as wide vs. pronotum significantly longer than wide), and the shape of the sclerites of the inner sac (thin and straight vs. compact and curved) ( Table 1 and Fig. 2A ) ( Müller 1911; Jeannel 1924; Pretner 1973; Mizerakis et al. 2022).

Etymology. After Bosnia and Herzegovina, a country where the type locality of the new subspecies is situated.

Geographic distribution. This subspecies inhabits a pit near the town of Ljubuški in southern Bosnia and Herzegovina —the Golubinka na Bubalove Njive Pit. This is the first discovery of the genus Speoplanes in this country. Previously, this genus was only known from caves and pits in several mountains in southern Croatia (Dalmatia) ( Fig. 1 ) ( Mizerakis et al. 2022; Čeplík 2023).

Figures

FIGURE 1. The distribution area of the genus Speoplanes. Light blue star—S. biocovensis bosnicus ssp. n.; light blue zones— S. biocovensis biocovensis; red zone—S. giganteus.

FIGURE 2. Habitus of the taxa of the genus Speoplanes (dorsal view). A—S. giganteus; B—S. biocovensis biocovensis. Scales = 5 mm.

FIGURE 3. Speoplanes biocovensis bosnicus ssp. n., habitus (dorsal view). A—holotype male; B—paratype female. Scales = 5 mm.

FIGURE 4. Morphology of head (left), pronotum (middle) and elytra (right) of Speoplanes biocovensis bosnicus ssp. n. (dorsal view). A–C—holotype male; D–F—paratype female. Scales = 1 mm.

FIGURE 5. Speoplanes biocovensis bosnicus ssp. n., mesoventral carina (lateral view). Scale = 0.5 mm.

FIGURE 6. Morphology of certain structures of the holotype male (A and B) and the paratype female (C–E) of Speoplanes biocovensis bosnicus ssp. n. A—aedeagus (dorsal view); B—aedeagus (lateral view); C—gonostyli (dorsal view); D— spermatheca (lateral view); E—abdominal sternite VIII (ventral view). Scales = 0.5 mm (A–C and E) and 0.1 mm (D).

Tables

TABLE 1. Linear measurements and morphometric ratios of Speoplanes biocovensis bosnicus ssp. n., S. biocovensis biocovensis and S. giganteus. The values outside the parentheses are mean values, while the values inside the parentheses are ranges.

Species/subspecies Character	TL*	HL/HW	HW/PW	AL*	AL/TL	A1L/A2L	A3L/A2L	A3L/A4L	A6L/A3L	A8L/A3L	A11L/A8L	A11W/A10W	PL/PW	PL/HL	PB/AM	EW/PW	EL/EW in males	8.32 (8.03–8.60)	1.17 (1.10–1.22)	0.69 (0.64–0.73)	8.98 (8.38–10.03)	1.08 (1.03–1.16)	0.62 (0.54–0.68)	1.04 (0.97–1.11)	0.79 (0.74–0.87)	1.23 (1.15–1.30)	0.98 (0.92–1.11)	1.13 (0.99–1.22)	0.89 (0.76–1.00)	0.99 (0.95–1.03)	1.24 (1.16–1.29)	1.45 (1.34–1.51)	1.66 (1.54–1.76)	2.04 (2.00–2.09)	8.25 (7.22–8.71)	1.08 (0.99–1.17)	0.72 (0.70–0.77)	9.50 (8.66–10.19)	1.13 (1.00–1.20)	0.63 (0.60–0.69)	1.09 (1.00–1.20)	0.78 (0.69–0.81)	1.27 (1.23–1.29)	1.03 (0.99–1.05)	1.02 (0.93–1.19)	0.98 (0.93–1.00)	1.07 (1.01–1.17)	1.35 (1.26–1.41)	1.40 (1.31–1.47)	1.66 (1.58–1.72)	2.16 (2.11–2.20)	7.84 (7.47–8.03)	1.18 (1.09–1.24)	0.74 (0.72–0.75)	10.79 (10.42–11.15)	1.31 (1.30–1.32)	0.61 (0.53–0.67)	1.17 (1.14–1.20)	0.82 (0.81–0.83)	1.24 (1.22–1.27)	1.04 (1.01–1.07)	0.91 (0.87–0.96)	1.05 (0.80–1.30)	1.03 (1.00–1.05)	1.20 (1.09–1.27)	1.38 (1.35–1.45)	1.69 (1.61–1.73)	1.97 (1.86–2.13)
TL*	8.32 (8.03–8.60)	8.25 (7.22–8.71)	7.84 (7.47–8.03)
HL/HW	1.17 (1.10–1.22)	1.08 (0.99–1.17)	1.18 (1.09–1.24)
HW/PW	0.69 (0.64–0.73)	0.72 (0.70–0.77)	0.74 (0.72–0.75)
AL*	8.98 (8.38–10.03)	9.50 (8.66–10.19)	10.79 (10.42–11.15)
AL/TL	1.08 (1.03–1.16)	1.13 (1.00–1.20)	1.31 (1.30–1.32)
A1L/A2L	0.62 (0.54–0.68)	0.63 (0.60–0.69)	0.61 (0.53–0.67)
A3L/A2L	1.04 (0.97–1.11)	1.09 (1.00–1.20)	1.17 (1.14–1.20)
A3L/A4L	0.79 (0.74–0.87)	0.78 (0.69–0.81)	0.82 (0.81–0.83)
A6L/A3L	1.23 (1.15–1.30)	1.27 (1.23–1.29)	1.24 (1.22–1.27)
A8L/A3L	0.98 (0.92–1.11)	1.03 (0.99–1.05)	1.04 (1.01–1.07)
A11L/A8L	1.13 (0.99–1.22)	1.02 (0.93–1.19)	0.91 (0.87–0.96)
A11W/A10W	0.89 (0.76–1.00)	0.98 (0.93–1.00)	1.05 (0.80–1.30)
PL/PW	0.99 (0.95–1.03)	1.07 (1.01–1.17)	1.03 (1.00–1.05)
PL/HL	1.24 (1.16–1.29)	1.35 (1.26–1.41)	1.20 (1.09–1.27)
PB/AM	1.45 (1.34–1.51)	1.40 (1.31–1.47)	1.38 (1.35–1.45)
EW/PW	1.66 (1.54–1.76)	1.66 (1.58–1.72)	1.69 (1.61–1.73)
EL/EW in males	2.04 (2.00–2.09)	2.16 (2.11–2.20)	1.97 (1.86–2.13)

*—values in mm.