Synarmostes benaraensis, 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 : 126-127

Synarmostes benaraensis sp. nov.

( Figs 2 c , 4 j-l, 7 d, 8 b, 9 a-b, i, n, 21 e-h, 29 e-g, 36) http://zoobank.org/ urn:lsid:zoobank.org:act:2AC4D9A5-C490-4A1E-9F9C-7DCB77CE0E01

Type series. Holotype, ♂, deposited in the collection of the California Academy of Sciences , San Francisco, CA, USA, labelled as follows: / CASTYPE 20245 / Mayotte: Mont Benara 30 Nov. – 2 Dec. 2007 elev. 425 m 12°52’33”S 045°09’24”E Calif. Acad. of Sciences coll. B. L. Fisher et al. sifted litter rainforest collection code: BLF18962 / Synarmostes benaraensis n. sp. det. A. Ballerio 2020 Holotypus ♂ / [distended, glued on card, dissect- ed, male genitalia glued in DMHF resin on a separate card, same pin]. Paratypes [30 ♂♂ dissected]: 446 specimens (370 in CASC and 76 in ABCB), same collecting data as holotype .

Diagnosis. Synarmostes benaraensis 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) punctation of pronotum and elytra dense, j) parameres with apex enlarged and rounded in lateral view (less rounded than in S. humilis ), k) elytral inferior sutural stria ending before humeral area. Synarmostes benaraensis 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 = 0.6 mm; HW = 1.1 mm; PL = 1.0 mm; PW = 1.7 mm; EL = 1.7 mm; EW = 1.6 mm. Overall morphology as in generic diagnosis. Small-sized flightless Synarmostes . Body strongly 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 = 1.40, clypeal apex obtuse, apical projection distinctly protruding and sharp; dorsal ocular area small, interocular distance about 17 times the maximum width of dorsal ocular area, inferior ocular area small, head dorsal surface with disc almost smooth, sides of disc covered by sparse shallow medium-sized simple comma-shaped punctation mixed to some horseshoe-shaped punctures with opening directed inwards. Fore margin with one or two transverse large comma-shaped punctures. Interpunctural distance of punctures once or twice larger than their width. Vertex smooth with one transverse impressed line shortly interrupted in the middle. Pronotum: subrectangular (W/L ratio = 1.66), regularly convex, pronotal surface with disc almost smooth and another smaller smooth area at sides, apart from the small smooth area sides covered by medium-sized sparse shallow transverse comma-shaped punctures, each one having a simple setigerous puncture inside. Interpunctural distance shorter than punctural width. Scutellum : almost completely smooth. Elytra: longer than wide (W/L ratio = 0.89); subrectangular (dorsal view); inferior sutural stria ending before humeral area; humeral callus indistinct; elytral surface regularly convex, uniformly covered by sparse shallow punctation. Interpunctiural distance once or twice the maximum width of punctures. Punctures transverse comma-shaped near base and sides of elytra, becoming longitudinal comma-shaped mixed to a few horseshoe-shaped punctures with opening directed backwards on medial third, each one having a simple setigerous puncture inside. Elytral distal third with four raised longitudinal carinae (excluding elytral suture) sometimes with a longitudinal impressed irregular line between them. Wings: flightless (apterous). Male genitalia: aedeagus (L = 0.9 mm) with parameres as in Figs 29 e-f, spiculum gastrale (L = 0.8 mm) as in Fig. 29 g .

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

Distribution and habitat. Known only from the type locality, set in one of the four main mountain ranges of Mayotte (the Bénara massif, in the centre of the island) ( Fig. 95 a ). The type series was collected by sifting leaf litter in rainforest. The collecting locality falls within the protected area “Réserve Forestière des Monts Bénara”.

Figures

Fig. 2 – a, Philharmostes indri sp. nov., aedeagus (bap: basal apophysis of parameres; e: endophallites; ep: endophallus; te: temones; p: paramere); b, Goudotostes lokobensis sp. nov., spiculum gastrale (sg: spiculum; a: arm of spiculum; nh: ninth hemisternite); c, Synarmostes benaraensis sp. nov., head (cap: clypeal apical projection; cl: clypeus; ge: gena; doa: dorsal ocular area; gc: genal canthus; fr: frons; tlv: transverse line of vertex; v: vertex; m: man- dible). White semicircle delimitates the clypeal area (photos not to scale).

Fig. 4 – Heads of Synarmostes in ventral, lateral and dorsal views (not to scale) in order to show the extent of ocular area, a–c, Synarmostes tibialis (example of large–sized ventral ocular area); d–f, Synarmostes annamariae sp. nov. (example of medium–sized ventral ocular area); g–i, Synarmostes fortis sp. nov. (example of small–sized ventral ocular area and vestigial dorsal ocular area); j–l, Synarmostes benaraensis sp. nov. (example of small–sized ventral ocular area).

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.