Synarmostes karthalaensis, Ballerio, 2021

Ballerio, Alberto, 2021, The Ceratocanthinae of Madagascar and Comoro Islands: a revision of the genera Synarmostes and Goudotostes, and of the flightless Philharmostes, with description of 64 new species (Coleoptera: Scarabaeoidea, Hybosoridae), Fragmenta entomologica 53 (2), pp. 105-282 : 158-159

Synarmostes karthalaensis sp. nov.

( Figs 20 e-h, 29 n-p, 35) http://zoobank.org/ urn:lsid:zoobank.org:act:1288BBFB-A7E9-4B13-9CCE-EA112547CCF1

Type series. Holotype, ♂, deposited in the collection of the California Academy of Sciences , San Francisco, CA, USA, labelled as follows: / CASTYPE 20254 / Comoros: Grand Comore , Karthala elev. 1125 m 13-14 March 2008 11°48’48”S 043°25’10”E Calif. Acad. of Sciences coll. B. L. Fisher et al. montane rainforest sifted litter collection code: BLF 19700 / Synarmostes karthalaensis n. sp. det. A. Ballerio 2020 Holotypus ♂ / [distended, glued on card, dissected, male genitalia glued on a separate card, same pin]. Paratypes [5 ♂♂ dissected]: 1 specimen ( CASC), same collecting data as holotype. 4 specimens ( CASC): / Comoros: Grand Comore , Karthala elev. 1000 m 14-15 March 2008 11°49’37”S 043°25’46”E Calif. Acad. of Sciences coll. B. L. Fisher et al. montane rainforest sifted litter collection code: BLF 19734/. 13 specimens (8 in CASC and 5 in ABCB): / Comoros: Grand Comore, Karthala elev. 1235 m 17-19 March 2008 11°45’12”S 043°18’28”E Calif. Acad. of Sciences coll. B. L. Fisher et al. montane rainforest sift- ed litter collection code: BLF 19947 /.

Diagnosis. Synarmostes karthalaensis sp. nov. can be differentiated from all other species of Synarmostes by the following combination of characters: a) small size, b) ventral ocular area small-sized, c) dorsal ocular area present, d) dorsal setation present (20×), e) flightlessness, f) carinae of elytral apical third regular (without tubercles or oth- er irregularities), g) scutellum smooth, without punctation, h) pronotum with an anteromedian area smooth, i) elytral horseshoe-shaped punctation dense and lerge, j) parameres gently falcate in lateral view, (less falcate than in S. grinteri sp. nov.) k) elytral inferior sutural stria not reaching humeral area. Synarmostes karthalaensis sp. nov. belongs to the humilis group of species and can be distinguished from the other species of the group only with the examination of the aedeagus, which has the distinctive shape indicated under letter j) above.

Description. Size: HL = 0.8 mm; HW = 1.2 mm; PL = 1.0 mm; PW = 1.9 mm; EL = 2.1 mm; EW = 1.8 mm. Overall morphology as in generic diagnosis. Small-sized flightless Synarmostes . Body moderately convex. Dark-brown with bronze sheen, shiny, dorsum with setigerous punctures bearing a medium-sized fine seta (20×), underside, tarsi and antennae reddish-brown, setation yellowish-brown. Head: W/L ratio = 1.42, clypeal apex obtuse, apical projection distinctly protruding and sharp; dorsal ocular area small, interocular distance about 14 times the maximum width of dorsal ocular area, inferior ocular area small; head dorsal surface with disc covered by sparse small comma-shaped punctures, sides of disc covered by sparse small short horseshoe-shaped punctation mixed to some small comma-shaped punctures with opening directed inwards. Fore margin with one or two transverse large comma-shaped punctures. Interpunctural distance of punctures irregular: half their width or once larger than their width. Each horseshoe-shaped or comma-shapaed puncture bearing a simple setigerous puncture internally. Vertex smooth with a transverse impressed line shortly interrupted in the middle. Pronotum: subrectangular (W/L ratio = 1.8), regularly convex, pronotal surface with disc almost smooth, with only some very sparse shallow comma-shaped punctures, each one bearing a simple setigerous puncture internally, sides covered by medium-sized shallow transverse horseshoe-shaped punctures, sometimes anastomizing, each one having a simple setigerous puncture internally. Interpunctural distance shorter than punctural width. Scutellum : almost completely smooth. Elytra: longer than wide (W/L ratio = 0.83); subrectangular (dorsal view); inferior sutural stria ending before humeral area; humeral callus indistinct; elytral surface regularly convex, uniformly covered by relatively dense and very shallow punctation. Interpunctiural distance once the maximum width of punctures. Punctures transverse horseshoe-shaped with opening directed backwards or outwards, becoming larger on distal third, each one having a simple setigerous puncture internally. Elytral distal third with four raised longitudinal carinae (excluding elytral suture) sometimes with a longitudinal shallow irregular line between them. Wings: flightless (apterous). Male genitalia: aedeagus (L = 1.1 mm) with parameres as in Figs 29 n-o, spiculum gastrale (L = 0.9 mm) as in Fig. 29 p .

Etymology. Latin adjective in the nominative singular, meaning “from Karthala”, the type locality.

Distribution and habitat. Known only from the type locality ( Fig. 95 b-d), the slopes of the highest peak of the island (a volcano). The type series was collected by sifting leaf litter in montane rainforest.

Figures

Fig. 20 – Synarmostes grinteri sp. nov., a, dorsal view of distended paratype; b, ventral view of rolled up paratype; c, dorsal view of rolled up paratype; d, lateral view of rolled up paratype; Synarmostes karthalaensis sp. nov., e, dorsal view of distended paratype; f, ventral view of rolled up paratype; g, dorsal view of rolled up paratype; h, lateral view of rolled up paratype.

Fig. 29 – Aedeagi and spicula gastrales, a, Synarmostes humilis, holotype. b–d, Synarmostes humilis (Mont Combani); e–g, Synarmostes benaraensis sp. nov., paratype; h–j, Synarmostes chonguimontis sp. nov., paratype; k–m, Synarmostes dapaniensis sp. nov., paratype; n–p, Synarmostes karthalaenisis sp. nov., paratype; q–s, Synarmostes grinteri sp. nov., paratype.

Fig. 95 – Habitat, Comoro islands (photos by Brian Fisher), a, Mayotte, landscape from Mont Benara, habitat of Synarmostes benaraensis sp. nov. and Goudotostes mayottensis sp. nov.; b–d, three views of the humid forest understory of Mont Karthala (Grande Comore), habitat of Synarmostes karthalaensis sp. nov.