Synarmostes dapaniensis, 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 : 154-155

Synarmostes dapaniensis sp. nov.

( Figs 19 e-h, 29 k-m, 36) http://zoobank.org/ urn:lsid:zoobank.org:act:6778E16B-7CBE-41D5-8635-B4BC9C6C0D4A

Type series. Holotype, ♂, deposited in the collection of the California Academy of Sciences , San Francisco, CA, USA, labelled as follows: / CASTYPE 20250 / CASENT 8135305 / Mayotte: Dapani 2-4 December 2007 elev. 135 m 12°57’46”S 045°09’01”E Calif. Acad. of Sciences coll. B. L. Fisher et al. sifted litter rainforest collection code: BLF19060 / Synarmostes dapaniensis n. sp. det. A. Ballerio 2020 Holotypus ♂ / [distended, glued on card, dissected, male genitalia glued in DMHF resin on a separate card, same pin]. Paratypes [25 ♂♂ dissected]: 363 specimens (300 in CASC and 63 in ABCB), same collecting data as holotype .

Diagnosis. Synarmostes dapaniensis 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 other irregularities), g) scutellum smooth, without punctation, h) pronotum with an anteromedian area smooth, i) parameres with apex enlarged, transverse and hammer-like, j) elytral inferior sutural stria ending before humeral area. Synarmostes dapaniensis 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 i) above.

Description. Size: HL = 0.5 mm; HW = 1.0 mm; PL = 0.9 mm; PW = 1.6 mm; EL = 1.6 mm; EW = 1.5 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 = 1.44, clypeal apex obtuse, apical projection distinctly protruding and sharp; dorsal ocular area small, interocular distance about 27 times the maximum width of dorsal ocular area, ventral ocular area small; head dorsal surface with disc almost smooth with only a few simple shallow punctures, sides of disc covered by sparse medium-sized 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 irregular: half their width or once or twice larger than their width. Vertex smooth with one transverse impressed line shortly interrupted in the middle. Pronotum: subrectangular (W/L ratio = 1.76), regularly convex, pronotal surface with disc almost smooth, with only some sparse shallow simple punctures, sides covered by large-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 = 0.82); subrectangular (dorsal view); inferior sutural stria ending before humeral area; humeral callus indistinct; elytral surface regularly convex, uniformly covered by very sparse and very shallow punctation. Interpunctiural distance once to four times the maximum width of punctures. Punctures transverse comma-shaped near base and sides of elytra, becoming 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 k-l, spiculum gastrale (L = 0.9 mm) as in Fig. 29 m .

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

Distribution and habitat. Known only from the type locality, set in the southern portion of the island. The type series was collected by sifting leaf litter in rainforest.

Figures

Fig. 19 – Synarmostes chonguimontis sp. nov., a, dorsal view of holotype specimen; b, ventral view of rolled up paratype; c, dorsal view of rolled up paratype; d, lateral view of rolled up paratype; Synarmostes dapaniensis sp. nov., e, dorsal view of distended holotype; 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.