Synarmostes antsingyi Paulian 1979

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 : 124

Synarmostes antsingyi Paulian 1979

( Figs 16 a-d, 17: a-b, 31 a-c, 35)

Synarmostes antsingyi : Paulian 1979: 63 (key, description, distribution, iconography); Ocampo & Ballerio 2006: 190 (listing).

Type locality: “Antsalova, Antsingy, Rés. nat. 9” (now Parc National de Tsingy de Bemaraha).

Material examined. Holotype, ♂, in coll. MNHN: / Madagascar Ouest , S-P. Antsalova, Antsingy, Rés. nat. 9, A. Peyrieras, I-1975 / Synarmostes antsingyi n. sp. R. Paulian det. / Holotype /. Paratypes: 14 exx. [1 ♂ dissected] (in MNHN), same collecting data as holotype . Other material examined (not belonging to the type series): 113 exx. [3 ♂♂ dissected] (97 in CASC and 16 in ABCB): / Madagascar: Mahajanga Prov. Parc National Tsingy de Bemaraha, 3.4 km 93° E Bekopaka, Tombeau Vazimba Elev. 50 m 6-10 Nov. 2001 / 19° 8’ 31” S 044° 49’ 41” E coll: Fisher , Griswold et al. California Acad. of Sciences sifted litter, tropical dry forest collection code: BLF4232 /.

Diagnosis. Synarmostes antsingyi 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 absent (20×), e) flightlessness, f) carinae of elytral apical third regular (without tubercles or other irregularities), g) scutellum with transverse comma-shaped punctation, h) pronotal punctation consisting of transverse short comma-shaped punctures or horseshoe-shaped punctures, i) pronotum with an anteromedian area smooth or with very sparse punctation, j) head with sparse shallow small simple punctation. Synarmostes antsingyi belongs to the antsingyi group of species and is very similar to S. monoculus sp. nov. (with whom it shares the shape of parameres) and S. beankae sp. nov., these two species however differ from it because of the lack of a smooth area on pronotal disc and the sparser elytral punctuation (and S. monoculus sp. nov. also because of the absence of a dorsal ocular area). Description. Size: HL = 0.5 mm; HW = 1.1 mm; PL = 0.9 mm; PW = 1.7 mm; EL = 1.8 mm; EW = 1.7 mm. Overall morphology as in generic diagnosis. Small-sized flightless Synarmostes . Body convex. Dark-brown with bronze sheen, shiny, dorsum glabrous (20×), underside, tarsi and antennae reddish-brown, setation yellowish-brown. Head: W/L ratio = 1.54, clypeal apex obtuse, apical projection small but 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, except vertex, uniformly covered by small fine impressed simple punctures. Fore margin with one or two irregular transverse large comma-shaped punctures. Interpunctural distance of impressed simple punctures irregular: four to six times larger than their width. Vertex smooth with one continuous transverse impressed line. Pronotum: subrectangular (W/L ratio = 1.80), regularly convex, pronotal surface almost uniformly punctured, only sides, base and a small area on anterior portion of disc almost impunctate; punctures mostly comma-shaped, each one bearing a simple puncture internally, comma-shaped punctures transverse on disc and longitudinal at sides. Interpunctural distance mostly shorter than or as long as punctural width. Scutellum : with some transverse comma-shaped punctures. Elytra: longer than wide (W/L ratio = 0.88); subovoidal (dorsal view); inferior sutural stria reaching humeral area although under the form of a very shallow fine line; humeral callus indistinct; elytral surface regularly convex, uniformly covered by relatively dense irregular punctation. Interpunctural distance once or twice the maximum width of punctures. Punctures comma-shaped, small and transverse near base and sides of elytra, becoming larger and sometimes longitudunal or anstomizing on distal third, each one having a simple setigerous puncture internally. Elytral distal third with eight raised longitudinal carinae (excluding elytral suture), sometimes having a longitudinal shallow line among them. Wings: flightless (apterous). Male genitalia: aedeagus (L = 0.8 mm) with parameres as in Figs 31 a-b, spiculum gastrale (L = 0.7 mm) as in Fig. 31c .

Etymology. Noun in the genitive case. Paulian did not provide the etymology of the name, which obviously refers to the type locality.

Distribution and habitat. Known only from the type locality in western Madagascar ( Fig. 94 ). Specimens were collected by sifting litter in dry tropical forest. The vegetation cover of the area, a large limestone massif, is classified as “Dry deciduous forest” ( Goodman et al. 2018), also known as “Western dry forest” ( Moat & Smith 2007). The collecting locality falls within the protected area “Parc National de Tsingy de Bemaraha”, called “Antsingy d’Ants- alova” in past times.

Figures

Fig. 16 – Synarmostes antsingyi (Tsingy de Bemaraha), 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 beankae 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. 31 – Aedeagi and spicula gastrales, a–c, Synarmostes antsingyi (Tsingy de Bemaraha); d–f, Synarmostes beankae sp. nov., holotype; g–i, Synarmostes bekaraokae sp. nov., holotype; j–l, Synarmostes caterinae sp. nov., holotype; m–o, Synarmostes monoculus sp. nov., holotype.

Fig. 94 – Habitat, Tsingy de Bemaraha (photos by Brian Fisher), habitat of Synarmostes antsingyi, a, an example of an average Winkler mass sifting set by Brian Fisher and collaborators, b–c, two views of the karst forest.