Sinodrepanus schoenfeldi Montanaro, 2024

Montanaro, Giulio, 2024, New or poorly known species of Sinodrepanus Simonis, 1985 (Coleoptera: Scarabaeidae: Oniticellini), with the first identification key for the genus, Zootaxa 5537 (4), pp. 577-595 : 587-588

Sinodrepanus schoenfeldi Montanaro , new species

http://zoobank.org/ urn:lsid:zoobank.org:act:360CCBA6-69BE-4A35-9BBB-01D46ECC8EEC

( Figs. 1c–d , 2e–h, 2j , 3d, 3b, 3f )

Drepanocerus falsus : Janssens, 1953: 36, 37; Biswas & Chatterjee, 1985: 151 (?); Sewak, 2003: 253, 283 (?)

Drepanocerus exsul : Arrow, 1931: 381, 385; Sewak, 2003: 253 (?)

Drepenocerus exsul [sic!]: Sewak, 2003: 283 (?)

Type locality: Patkai Mountains , Assam state, India .

Type material examined. Holotype, ♂ ( BMNH): Assam / Patkai Mts. [wc, hb] // 61033 [wc, hb] // Doherty [wc, hb] // Fry Coll. / 1905-100. [wc, pb] // Determinated from / description G.J.A. / Oniticellus / exsul, Sharp [wc, pb except last two lines hb] // BMNH (E) / 1237595 [wc, pb] // Sinodrepanus / schoenfeldi n. sp. / HOLOTYPE ♂ / G. Montanaro det. 2024 [rc, hb]. Allotype: NE India, Arunachal Pradesh, Hunli vicinity, 28°19’32”N 95°57’31”E, 1300± 100m, FIT (flight interception trap), 26.v–1.vi.2012, L. Dembický legit [ NMPC]. Paratypes (4♂♂, 5♀♀). India: NE India, Arunachal Pradesh, Roing vicinity, 28°08’32”N 95°51’E, 500m, sifting+Winkler app. extraction, 2–5.vi.2012, L. Dembický legit [1♀, JSCS]. Laos: Oudomxai province, 17km NEE Oudomxai, 20°45’N 102°09’E, ~ 1100m, 1–9.v.2002, Vit Kubáň legit [2♂♂, 2♀♀, NMPC; 1♂, GMOC]; Phongsaly province, 4km E Ban Bun Neua, 21°38’N 101°57’E, ~ 1100m, Vit Kubáň legit [1♂, NMPC]; Bokeo province, 5km W Ban Toup, Bokeo Nature Reserve, 20°27–28’ N 100°45’ E, 500–700m, 4–18.v.2011 [1♀, NMBS]; Bokeo province, 5km W Ban Toup, Bokeo Nature Reserve, 20°27–28’ N 100°45’ E, 500–700m, 4–18.v.2011, M. Brancucci legit [1♀, NMBS].

Diagnosis. Sinodrepanus schoenfeldi new species can be easily separated from most Sinodrepanus species by the combination of the following characters: i) the longest setae on interstria 5 irregularly distributed, not arranged into tufts; ii) three teeth on the outer protibial margin; iii) male clypeus with two teeth plus an additional small stout median tooth ( Fig. 3b ); iv) females with a sharp small denticle between clypeal teeth ( Fig. 3d ); v) parameres with very short basolateral plate ( Figs. 2e–g ). Except for the third and last characters, all other features are also present in S. exsul , from which however it can be easily separated also by the punctured (not smooth) lateral surface of sternites 3–6 and the circular (not elongated) punctures of pronotal disc ( Fig. 3f ).

Description of the holotype, male. Flat, elongated, integument microreticulated, dark brown and partially with metallic lustre; antennae reddish-brown; body surface almost wholly covered by simple or ocellate punctures which carry light brown scale-like setae. Length: 8.6 mm. Head. Subpentagonal, clypeus covered by dense ocellate setigerous punctures; vertex with two weak, short longitudinal carinae bearing long testaceous bristles; carinae dividing the interocular space into three almost equal segments; frons bulging medially; lateral edge of genae obtusely angular; head margin obtusely angular in correspondence of clypeogenal junctions; anterior clypeal margin with two upturned teeth and a third, very small medial clypeal tooth, margin broadly obtusely angled medially. Pronotum. Subquadrangular, widening anteriorly, lateral margin approximately straight posteriorly; anterolateral angles evenly curved; posterior angles broadly rounded; posterior margin broadly rounded, obtuse medially; covered with ocellate setigerous punctures of uneven size, punctures circular on disc. Pronotal disc with 8 ill-defined longitudinal carinae bearing testaceous bristles (in order, from medial to lateral): 2 carinae on either side of the midline, reaching the anterior pronotal border but expiring before posterior edge, slightly converging at about the anterior 2/5 of their length, where disc is transversely swollen; laterally to these, 2 short carinae connected to the posterior pronotal border and 2 short oblique carinae anteriorly, connecting to the anterior part of the medial carinae; other 2 bulge-like oblique carinae on the posterior and anterior thirds of pronotum, close to the lateral margins. Elytra. Flat on the whole, interstria 1 raised, interstria 6 depressed longitudinally; interstriae 5–7 obliquely elevated next to humeral callus, interstria 6 depressed a little behind callus; striae broad, their borders clearly ridged, punctures marked, each one carrying a scale-like seta; interstriae uniformly covered with setigerous punctures; interstriae 1–3, 5 and 7 with a tuft of long setae apically; interstriae 1, 5 and 7 carrying longer setae, setae on interstria 5 irregularly distributed; interstria 8 covered with longer and more scattered setae.Scutellar shield approximately parallel-sided, smooth. Legs. Anterior surface of femur covered by dense small setigerous punctures and by scattered ocellate punctures carrying thicker setae. Protibia with distal margin obliquely truncated; ventral protibial margin strongly curved, slightly produced distally; apical protibial spur with distal half slightly bent; dorsal protibial margin with three small teeth. Tergite 8. Densely setigerous; strongly swollen medially, with two broad bulges; strongly depressed along anterior margin; with a longitudinal medial carina connected to the anterior margin. Ventral body surface. Abdominal sternites with a tuft of long setae laterally next to the epipleuron, evenly covered with setigerous punctures, setae longer medially. Metaventral disc covered by small ocellate punctures intermixed with few bigger punctures, with a pair of symmetrical shallow depressions next to posteromedian margin; lateral metaventral surface microreticulated, with big ocellate puctures intermixed with many smaller setigerous punctures. Genitalia ( Figs. 2e–h ). Basolateral plates of parameres relatively short, not reaching parameral apices in lateral view; parameral apices well developed, strongly bent downwards; parameral apices rounded in frontal view. Lamella copulatrix (LC) four-lobed: superior left lobe with a flattened digitiform expansion bent posteriorly; superior right lobe simple, flattened; inferior left lobe relatively thick, arched; inferior right lobe separated from the rest of the LC, associated with an inconspicuous additional sclerite.

Female (allotype). Similar to the male except for the following characters. Head. Symmetrical clypeal teeth more developed, space between them broader, median denticle more developed and sharp; clypeal margin slightly notched at clypeogenal margin. Legs. Outer protibial teeth larger than in the male; inner protibial margin not strongly curved. Tergite 8. Shorter than in the male. Ventral body surface. S8 longer than in the male. Genitalia ( Fig. 2j ). Vagina relatively poorly sclerotised, with many folds; infundibulum broadly curved distally.

Variation. Body size ranges from 8.0 to 9.0 mm. The clypeal margin can be more or less markedly angular at clypeogenal junctions. Punctures on the basal half of disc can sometimes be slightly oval, but never clearly elongated as in S. exsul . In one male the median clypeal denticle was completely effaced, probably due to wear. No significant external or genital differences were observed between specimens from India and those from Laos.

Verified distribution: India (Assam, Arunachal Pradesh), Laos ( Fig. 4 ). See the remarks in the “ Indian Sinodrepanus : an overlooked diversity?” section for more details.

Ecology. In India, this species inhabits evergreen rainforests on the eastern foothills of Himalaya.

Etymology. I am pleased to dedicate the new species to Joachim Schönfeld (Sinzig, Germany), specialist of Old World Scarabaeinae , to whom I am grateful for his friendly support and help in gathering important dung beetle specimens.

Remarks. This species was overlooked by several authors due to the similarity with S. falsus and S. exsul . This error was first made by Arrow, who identified the holotype of S. schoenfeldi new species as S. exsul and depicted it ( Arrow 1931: 385, fig. 55).

A remarkable feature of the new species is the presence of a third, tiny medial clypeal tooth in both males and females. This character is rare in Oniticellini , being found—to my knowledge—only in females of S. exsul and Scaptocnemis segregis Péringuey, 1901 ( Péringuey 1901), and in the Helictopleurus d’Orbigny, 1915 species of the fungicola -group ( Rossini et al. 2021). Curiously, evidence from multiple studies showed that the subtribe Drepanocerina , to which Sinodrepanus is currently assigned, and the genera Tiniocellus Péringuey, 1901 and Scaptocnemis Péringuey, 1901 , may be strictly related ( Ayivi et al. 2021; Breeschoten et al. 2016; Philips 2016). If this is the case, one may wonder whether the three-toothed clypeus shared by Sinodrepanus and Scaptocnemis is due to convergence or, instead, is a homologous character.

Figures

FIGURE 1. Habitus of Sinodrepanus species, dorsal view. S. exsul: male (a) and female (b). S. schoenfeldi new species: male paratype from Laos (c) and female paratype from India (d).

FIGURE 2. Genitalia of Sinodrepanus species. S. exsul: aedeagus in lateral (a), posterior (b) and dorsal (c) views; lamella copulatrix (d); female genitalia (i). S. schoenfeldi new species: aedeagus in lateral (e), posterior (f) and dorsal (g) views; lamella copulatrix (h); female genitalia (j).

FIGURE 3. Details of Sinodrepanus species. S. exsul: male (a) and female (c) head; posterior pronotal punctuation (e). S. schoenfeldi new species: male (b) and female (d) head; posterior pronotal punctuation (f). S. arrowi, lectotype (g) and its labels (h) (pictures by Jiří Hájek, NMPC).

FIGURE 4. Distribution of Sinodrepanus species. The position of the holotype of S. exsul is chosen arbitrarily within Thailand due to the lack of precise georeferentiation.