Synarmostes zahamenae, 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 : 166

Synarmostes zahamenae sp. nov.

( Figs 24 e-h, 32 k-m, 35) http://zoobank.org/ urn:lsid:zoobank.org:act:A43E3068-F291-41FA-937D-782303777A80

Type series. Holotype, ♂, deposited in the collection of the California Academy of Sciences, San Francisco, CA, USA, labelled as follows: / CASTYPE 20260 / CASENT 8135779 / Madagascar: Toamasina, Parc National de Zahamena, Onibe River elev. 780 m 21-23 February 2009 / 17° 45’ 33” S 048° 51’ 17” E California Acad. of Sciences coll. B. L. Fisher et al. sifted litter, rainforest BLF 22214/ Synarmostes zahamenae n. sp. det. A. Ballerio 2020 Holotypus ♂ / [distended, glued on card, dissected, male genitalia glued in DMHF resin on a separate card, same pin].

Diagnosis. Synarmostes zahamenae sp. nov. can be differentiated from all other species of Synarmostes by the following combination of characters: a) medium size, b) ventral ocular area medium-sized, c) dorsal ocular area present, d) dorsal setation absent (20×), e) flightlessness, f) pronotum without callosities on disc, g) pronotum slightly saddle-shaped in lateral view, h) elytral punctation on basal and median thirds large (punctures on basal third with an average width of about 1/22 the maximum width of each elytron) and mostly transversely oriented (mostly horseshoe-shaped, with branches tending to become parallel to each other), i) carinae of elytral apical third irregular (with some weak tubercles or other irregularities), j) parameres only slightly and shortly curved apically (lateral view). Synarmostes zahamenae sp. nov. belongs to the tibialis group of species and can be differentiated from the oth- er species of the group by the combination of characters b), c), g), h) and j).

Description. Size: HL = 1.0 mm; HW = 1.5 mm; PL = 1.4 mm; PW = 2.5 mm; EL = 2.5 mm; EW = 2.3 mm. Overall morphology as in generic diagnosis. Medium-sized flightless Synarmostes . Body moderately convex. Black with bronze sheen, shiny, dorsum glabrous (20×), underside, tarsi and antennae reddish-brown, setation yellowish. Head: W/L ratio = 1.42; clypeal apex obtuse, apical projection hardly appreciable; dorsal ocular area small, interocular distance about 13 times the maximum width of dorsal ocular area, ventral ocular area medium-sized; head dorsal surface uniformly covered by dense strongly impressed large simple punctation, smaller and less impressed on disc. Fore margin with some irregular transverse lines preceded by some transverse comma-shaped punctures. Interpunctural distance of simple impressed punctures irregular: from less than to once or three times larger than the punctural diameter. Vertex smooth with one continuous transverse impressed irregular line. Pronotum: subrectangular (W/L ratio = 1.96), irregularly convex, slightly depressed anteromedially giving a slight saddle-shaped appearance in lateral view, with fore margin slightly raised, base and sides with sparse punctation, disc covered by dense short transverse impressed comma-shaped punctures, sides of disc covered by dense small impressed horseshoe-shaped punctures. Interpunctural distance shorter than punctural diameter. Scutellum : base smooth, medi- an and distal third covered by several transverse small comma-shaped punctures.

Elytra: longer than wide (W/L ratio = 1.12); subovoidal (dorsal view); inferior sutural stria reaching humeral area; humeral callus absent; elytral surface regularly convex, covered by medium-sized dense horseshoe-shaped punctures with opening directed backward. Interpunctural distance irregular: once or twice the length of punctural diameter. Elytral distal third with at least eight raised longitudinal irregular carinae. Wings: flightless. Male genitalia: aedeagus (L = 0.9 mm) with parameres as in Figs 32 k-l, spiculum gastrale (L = 0.8 mm) as in Fig. 32 m .

Etymology. Noun in the genitive case, referring to the type locality.

Distribution and habitat. Known only from the type locality in Eastern Madagascar. The type series was collected by sifting leaf litter in rainforest. Zahamena forest is one of the last remaining patches of the once continuous rainforest area along the Eastern coast of Madagascar. The vegetation cover consists of “ moist evergreen forest” ( Goodman et al. 2018) also known as “humid forest” ( Moat & Smith 2007). The collecting locality falls within the protected area “Parc national de Zahamena”.

Within the studied material, females of other four ten- tative new species were examined. However, since the male genitalia have pivotal importance in distinguishing the species of the genus, those will remain undescribed.

Figures

Fig. 24 – Synarmostes makirovanae sp. nov., holotype, a, dorsal view of distended specimen; b, ventral view of rolled up specimen; c, dorsal view of rolled up specimen; d, lateral view of rolled up specimen; Synarmostes zahamenae sp. nov., holotype, e, dorsal view of distended specimen; f, ventral view of rolled up specimen; g, dorsal view of rolled up specimen; h, lateral view of rolled up specimen.

Fig. 32 – Aedeagi and spicula gastrales, a–c, Synarmostes annamariae sp. nov., paratype; d–e, Synarmostes eugenii sp. nov., holotype; f–h, Synarmostes parrilloi sp. nov., holotype; i–j, Synarmostes occidentalis sp. nov., holotype; k–m, Synarmostes zahamenae sp. nov., holotype; n–p, Synarmostes niger, paratype.