Synarmostes aes, 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 : 122-123

Synarmostes aes sp. nov.

( Figs 13 a-b, 14 a-d, 30 a-c, 35) http://zoobank.org/ urn:lsid:zoobank.org:pub:B3F75A2C-7603-4027-B8E1-F4A8B5A0CDD9

Type series. Holotype, ♂, deposited in the collection of the Field Museum of Natural History, Chicago, IL, USA, labelled as follows: / Madagascar: Province de Fianarantsoa, R. S. de Ivohibe , 8 km E Ivohibe, 22° 29’ 0” S 46° 58’ 1” E, 1200 m, 3-9.XI.1997, FMNH #97-507 , montane rainforest, Winkler extraction, B. L. Fisher, 1753 / Synarmostes aes n. sp. det. A. Ballerio 2020 Holotypus ♂ / [distended, glued on card, dissected, male genitalia glued on a separate card, same pin]. Paratypes: 2 ♀ (1 in FMNH and 1 in ABCB), same collecting data as holotype .

Diagnosis. Synarmostes aes sp. nov. can be differentiated from all other species of Synarmostes by the following combination of characters: a) large 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) sides of pronotum with a narrow longitudinal smooth area ( Fig. 13 a ), h) elytral punctation consisting of irregular rows of small transverse comma-shaped punctures, i) carinae of elytral apical third irregular (with some weak tubercles or other irregularities), j) elytra with the most external apical carina weakly bisinuate apically ( Fig. 13 b ), k) parameres in lateral view regularly curved apically (less than in S. separatus sp. nov.). Synarmostes aes sp. nov. belongs to the tibialis group of species. The habitus, mainly because of the pattern of pronotal and elytral punctation, recalls the one of the volant species, such as S. tibialis and S. niger , from which, however, it differs in being flightless and having medium-sized ventral ocular areas. It is very similar to S. separatus sp. nov. from which differs because of characters g), j) and k).

Description. Size: HL = 1.1 mm; HW = 1.8 mm; PL = 1.5 mm; PW = 3.0 mm; EL = 3.1 mm; EW = 2.9 mm. Overall morphology as in generic diagnosis. Large-sized flightless Synarmostes . Body moderately convex. Dark bronze with metallic sheen, shiny, dorsum with setigerous punctures bearing an extremely short simple seta (50×), 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 with disc covered by sparse strongly impressed simple punctation, becoming comma-shaped centrifugally. Comma-shaped punctures small-sized at base and sides, larger near fore margin. Fore margin with some transverse large comma-shaped punctures. Interpunctural distance of simple and comma-shaped punctures once or twice larger than punctural diameter. Vertex with a transverse line shortly interrupt- ed multiple times. Pronotum: subrectangular (W/L ratio = 1.83), regularly convex (not saddle-shaped in lateral view), disc covered by dense transverse comma-shaped punctures larger than the ones on head, sides covered by small horseshoe-shaped punctures with opening directed outwards, apart from a narrow longitudinal smooth area. Interpunctural distance shorter than punctural diameter. Scutellum : covered by several small impressed transverse comma-shaped punctures. Elytra: longer than wide (W/L ratio = 0.91); subrectangular (dorsal view); inferior sutural stria reaching the humeral area; humeral callus indistinct; elytral surface regularly convex, covered by an undefined number of longitudinal rows of punctures (striae). Punctures short, transversely oriented comma-shaped near base and sides of elytra, becoming longitudinally orient- ed comma-shaped on medial third and horseshoe-shaped with a broad opening directed backwards on distal third. Elytral punctation impressed as pronotal one. Intersitrae barely discernable, smooth, at distal third raised and cariniform, with at least eight irregular apical carinae visible; the most external apical carina weakly bisinuate apically. Wings: flightless (brachypterous). Male genitalia: aedeagus (L = 1.2 mm) with parameres as in Figs 30 a-b, spiculum gastrale (L = 1.0 mm) as in Fig. 30 c .

Etymology. Noun in apposition. Latin noun meaning “bronze”, due to the colour of this beetle.

Distribution and habitat. Known only from the type locality in Eastern Madagascar. The type series was collected by sifting leaf litter in rainforest. The vegetation cover consists of “medium altitude moist evergreen forest” ( Goodman et al. 2018) also known as “humid forest” ( Moat & Smith 2007). The collecting locality falls within the protected area “Paysage harmonieux protegé du corridor forestier Ambositra-Vondrozo”.

Figures

Fig. 13 – a, Synarmoste aes sp. nov., lateral view showing smooth area on pronotal side (ps: pronotal side); b, Synarmoste aes sp. nov., view of distal third of elytra showing the weak sinuation of apical carina (cp: carina profile); c, Synarmoste separatus sp. nov., lateral view showing punctate area on pronotal side (ps: pronotal side); d, Synarmoste separatus sp. nov., view of distal third of elytra showing the strong sinuation of apical carina (cp: carina profile); e, Synarmostes benaraensis sp. nov., ventral side of elytron showing the presence of three mites (arrow indicates the mites); f, detail of another elytron of Synarmostes benaraensis sp. nov. showing two mites.

Fig. 30 – Aedeagi and spicula gastrales, a–c, Synarmostes aes sp. nov., holotype; d–f, Synarmostes separatus sp. nov., holotype; g–i, Synarmostes compactus sp. nov., holotype; j–l, Synarmostes fortis sp. nov., holotype; m–o, Synarmostes makirovanae sp. nov., holotype; p–r, Synarmostes lavasoae sp. nov., holotype.