Spelaeobates (Spelaeobates) novaki Mueller , 1901

Curcic, Srecko, Vesovic, Nikola, Vrbica, Maja, Popovic, Slađana, Radovanovic, Zeljko, Curcic, Nina B., Yamashkin, Anatoliy A., Radovic, Dejan, Yamashkin, Stanislav A., Vranic, Sofija & Rađa, Tonci, 2023, The surprising discovery of two new subterranean Leptodirini of the genus Spelaeobates Mueller, 1901 (Coleoptera, Leiodidae, Cholevinae) from Croatia after more than a century, Subterranean Biology 46, pp. 21-46 : 21

Spelaeobates (Spelaeobates) novaki Mueller, 1901

Figs 7 , 8

Type material.

Topotypes : one male and four females (IZFB) labeled as follows: "CROATIA, NORTHERN DALMATIA: island of Dugi Otok, village of Savar, Strašna Peć Cave, 70 m a.s.l., 44°00'16.6"N, 15°02'19.1"E, 1.VII.1997, TR". All topotypes are labeled with white, printed locality labels (Fig. 7 ).

Remarks.

For purpose of comparisons, we have examined the topotype material of S. (S.) novaki collected by the last author of this study. This species is described on the basis of the type series of specimens collected in September 1900 by Josef Müller and Petar Novak in two caves on two northern Dalmatian islands - the Strašna Peć Cave, village od Savar, island of Dugi Otok, and a small cave in the village of Mali Iž, island of Iž ( Müller 1901). Later Pretner (1973) determined the correct name of the second cave site (its exact name is the Jezero Cave). In his original description of S. (S.) novaki , Müller (1901) did not indicate how many specimens are included in the type series, nor is there any information about their sex or where they were deposited. Based on the data and illustrations in the paper of Müller (1901), it can be concluded that the type series of this species consisted of both male and female specimens.

After reading both the original description of S. (S.) novaki by Müller (1901) and the subsequent morphological data on the species by Jeannel (1924), as well as a careful examination of the topotype specimens of S. (S.) novaki , we have found that some of the data given in the earlier literature on the morphology of the species do not agree with the characteristics of the topotype specimens we have observed. Namely, both Müller (1901) and Jeannel (1924) reported that the parameres of the aedeagus of S. (S.) novaki lack setae. Furthermore, in the drawing of the aedeagus by Müller (1901), no parameral setae are present. However, in the topotype male of S. (S.) novaki , we observed that each paramere has four apical setae, as in S. (S.) coriniensis sp. nov. In the work of Müller (1901), it was noted that the head of S. (S.) novaki is nearly twice as long as wide, the pronotum is 1.5 times longer than wide, antennomeres I and II are of similar width, the last antennomere is wider than the preceding ones, and the first protarsomere of the males is about twice as long as wide. However, in the specimens of the same species that we have examined, the head is about 1.5 times as long as wide, the pronotum is nearly one third longer than wide, antennomere I is wider than antennomere II, the last antennomere is narrower than the preceding ones, and the first protarsomere of the male is about 1⅔ times longer than wide (Table 1 ). Müller (1901) noted that the pronotum of S. (S.) novaki is finely punctate, but Jeannel (1924) reported that it is strongly punctate, which we also observed in our specimens. For these reasons, we have decided to redescribe the species S. (S.) novaki and add additional data on its morphology here.

Redescription.

Small-sized leptodirine. TL M 2.63 mm (2.57 mm in males, 2.64 mm in females), R 2.57-2.70 mm (2.57 mm in males, 2.60-2.70 mm in females).

Habitus: Body shape leptodiroid (Fig. 7A, B ), colour yellowish-brown.

Integument: Lustrous, microsculptured both dorsally and ventrally (Fig. 7C, E, F, H ). Densely distributed deep punctures present on head, pronotum (often merged) and elytra (particularly strong) (Fig. 7C, E, F ). Entire body dorsally covered with yellow pubescence of short length (erect on head, while recumbent on both pronotum and elytra) (Fig. 7A, B ).

Head: About one and a half times as long as wide (HL/HW M 1.47, R 1.38-1.53), slightly more elongate in males (HL/HW M 1.49 in males, M 1.46 in females), with no eyes, occipital carina in the shape of a curved concave line (Fig. 7A, C ). Head widest between first third and half. Frons roundly impressed between antennal insertions. Labrum transverse, with a few long setae. First maxillary palpomere of similar length and width, shorter than second maxillary palpomere. Maxillary palpomeres II and III of similar length (M3L/M2L M 1.09, R 1.00-1.18). Penultimate maxillary palpomere widened apically. Ultimate maxillary palpomere short, slender, gradually narrowing apically. Antennae inserted in basal quarter of head, thin, narrow proximally (except for first two antennomeres, which are thickened), slightly widened distally, longer in males, AL M 1.81 mm, R 1.75-1.93 mm (1.93 mm in males, 1.75-1.79 mm in females), not reaching end of elytra in both sexes (Fig. 7A, B, D ). Antennomeres I and II short and wide, of similar length, second of which slightly narrower. Following four antennomeres thinner and slightly longer than antennomere II. Antennomere III longer than adjacent antennomeres (A3L/A2L M 1.37, R 1.23-1.42; A3L/A4L M 1.24, R 1.21-1.31). Antennomeres VII, IX, and X quite expanded distally. Antennomere VIII relatively short and narrow, shorter and narrower than anatennomeres VII, IX, X, and XI. Ultimate antennomere slender, widened sub-distally, then narrowing apically, narrower than penultimate one (A11W/A10W M 0.75, R 0.67-0.83). Antennomere VIII shortest, while antennomeres IX and XI longest. Other ratios of length of certain antennomeres: A6L/A3L M 0.79, R 0.76-0.82; A8L/A3L M 0.65, R 0.59-0.71; A11L/A8L M 2.27, R 2.09-2.40.

Prothorax: Pronotum bell-shaped, elongate, longer than wide (PL/PW M 1.29, R 1.26-1.32; M 1.32, R 1.32 in males; M 1.28, R 1.26-1.30 in females), widest slightly before anterior third, broader (HW/PW M 0.93, R 0.88-0.98) and shorter than head (PL/HL M 0.96, R 0.90-0.98) (Fig. 7A, E ). Lateral margins rounded anteriorly, after which they constrict towards posterior end, slightly concave posteriorly. Pronotal base straight, somewhat shorter than elytral base. PB/AM M 0.86, R 0.81-0.90. Anterior margin straight. Lateral margins and pronotal base rimmed. Fore pronotal angles weakly expressed, rounded, obtuse. Hind pronotal angles well-expressed, obtuse, not protruding backwards. Pronotal disc moderately convex (Fig. 7B ).

Mesothorax: Mesoventral carina very low, barely noticeable, with a few setae (Fig. 7G ). No tooth, anterior and posterior margins observed. Mesoventrite with a long, sub-parallel process between mesocoxae (Fig. 7H ). Scutellum large, sub-triangular (Fig. 7E, F ).

Metathorax: Metaventrite without carina.

Elytra: Wide, ovoid, of similar width in males and females (EL/EW M 1.53, R 1.53 in males; M 1.55, R 1.49-1.60 in females), markedly wider than pronotum (EW/PW M 2.44, R 2.37-2.50) (Fig. 7A, F ). Maximum width a little before middle. Lateral margins arcuate. Marginal furrows not visible from above. Shoulders barely visible, obtuse, covered by hind pronotal angles. Elytral disc markedly convex, steeply declining both basally and apically in lateral view (Fig. 7B ). Parasutural stria absent. Elytral apex slightly attenuated, rounded. Pygidium not entirely covered by elytra.

Legs: Elongate and slender (Fig. 7A, B ). Femora widened basally, constricted in distal half. Tibiae thin, gently curved, gradually widening distally. Each protibia with a very fine comb over entire apical third of outer margin. Fore tarsi four-segmented in both sexes, only first protarsomere in males dilated (P1W/P2W M 1.67, R 1.67). Tarsal claws thin, elongate, curved, pointed apically.

Male genitalia: Aedeagus elongate, slender, small, well chitinised (Fig. 8A, B ). Median lobe in dorsal view straight, sub-parallel, gradually narrowing distally, with a rounded apex, longer than parameres (Fig. 8A ). Median lobe in lateral view quite flattened, curved basally, straight proximally and slightly bent downward distally, narrowing apically (Fig. 8B ). Basal bulb small, narrow, sub-parallel and slightly widened distally in dorsal view (Fig. 8A ), while elongate and widened basally in lateral view (Fig. 8B ). Tegmen wide from above (Fig. 8A ), in the shape of a ring around basal bulb (Fig. 8B ). Parameres elongate, slender, arcuate, sub-apically curved exteriorly, each with a moderately widened rounded apex in dorsal view (Fig. 8A ), while almost straight, sub-parallel in lateral view (Fig. 8B ). Each paramera bearing four apical close-set setae, two of which longer, while two shorter (Fig. 8A, B ). No copulatory piece observed within inner sac (Fig. 8A, B ).

Female genitalia: Spermatheca small, chitinised, straight basally, curved sub-apically, spherical both basally and apically (Fig. 8C ). Gonostyli short, straight, moderately widened, gradually narrowing distally, pointed apically. Each gonostylus carrying one long apical seta.

Male abdominal sternite IX (urite): Small, narrowing apically, sub-triangular.

Female abdominal ventrite VIII: Small, transverse, with no anterior process, hairy, especially posteriorly, slightly bilobed distally (Fig. 8D ).

Geographic distribution.

This species inhabits two caves located on two northern Dalmatian islands - the Strašna Peć Cave (island of Dugi Otok) and the Jezero Cave (island of Iž) ( Pretner 1973). It is possible that it also inhabits other subterranean sites on the same and neighbouring islands.

Figures

Figure 7. Bright-field images of the morphological structures of topotype male (A-G) and topotype female (H) of Spelaeobates (Spelaeobates) novaki from the Strasna Pec Cave, village of Savar, island of Dugi Otok, northern Dalmatia, Croatia A habitus, dorsal view B habitus, lateral view C head, dorsal view D left antenna, dorsal view E pronotum and scutellum, dorsal view F elytra, dorsal view G mesoventral carina, lateral view H mesoventrite, ventral view. Scale bars: 1.0 mm (A, B); 0.5 mm (D, F); 0.25 mm (C, G); 0.2 mm (E, H).

Figure 8. Bright-field images of certain morphological traits of topotype male (A, B) and topotype female (C, D) of Spelaeobates (Spelaeobates) novaki from the Strasna Pec Cave, village of Savar, island of Dugi Otok, northern Dalmatia, Croatia A aedeagus, dorsal view B aedeagus, lateral view C spermatheca, lateral view D abdominal ventrite VIII. Scale bars: 0.2 mm (A, B, D); 0.1 mm (C).