Philharmostes acutus, 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 : 248-249

Philharmostes acutus sp. nov.

( Figs 82 e-h, 85 g, 87 a-c, 89) http://zoobank.org/ urn:lsid:zoobank.org:act:F092F52C-5DA5-48A6-82C1-01B7A7E8D3F1

Type series. Holotype, sex unstated, deposited in the collection of the California Academy of Sciences, San Francisco, CA, USA, labelled as follows: / CASTYPE 20288 / CASENT 8135322 / Madagascar: Toamasina Prov. Parc national Mananara-Nord , 7.1km 261° Antanambe elev 225 m 14 November 2005 / 16° 27’ 18” S 049° 47’ 15” E / California Academy of Sciences coll. Brian L. Fisher et al. sifted litter rainforest BLF 12556/ Philharmostes acutus n. sp. det. A. Ballerio 2020 Holotypus /. Paratypes: 3 exx. (sex unstated) (2 in CASC and 1 in ABCB), same collecting data as holotype .

Diagnosis. Philharmostes acutus sp. nov. can be differentiated from all other species of Philharmostes by the following combination of characters: a) flightlessness, b) dorsal ocular area small, c) head with clypeal disc covered by large impressed simple punctation, d) dorsum with brown colour, without metallic sheen, e) pronotal fore angles broadly truncate, f) pronotum with disc slightly raised with respect to sides, g) pronotal disc covered by large horseshoe-shaped punctation mixed to some large comma-shaped punctation, h) elytral lateral carina complete, h) elytral lateral carina sharp, i) elytral lateral carina slightly sinuate in lateral view, j) elytral lateral carina in correspondence with humeral area forming a sharp angle (dorsal view), k) elytral basal third with parasutural area with large horseshoe-shaped punctures with opening directed backwards or outwards, l) elytral punctation made of large horseshoe-shaped punctures, m) elytral fore angles distinct and strong, n) head with vertex having one irregular transverse row of larger impressed simple punctures.

Description. HL: 0.6 mm; HW: 1.1 mm; PL: 1.0 mm; PW: 1.9 mm; EL: 2.0 mm; EW 2.0; overall morphology as in generic diagnosis. Small flightless Ceratocanthinae . Body moderately convex. Dark brown, shiny, dorsum glabrous (40×), underside, tarsi and antennae reddish-brown.

Head: W/L ratio = 1.36; apical margin triangular with angle blunt and obtuse and sides weakly curved; genae produced outwards, acute; genal canthus complete, fused with the occipital portion of head; dorsal ocular area small-sized, interocular distance about 19 times the maximum width of dorsal ocular area, disc uniformly covered by large impressed simple punctation, fore margin with some irregular impressed transverse short lines. Interpunctural distance of simple punctures once to three times larger than punctural diameter. Pronotum: short and transverse (W/L ratio = 1.73), weakly convex, surface irregular, with discal area slightly raised with respect to sides; base and sides broadly rounded (dorsal view); fore margin thick, distinct along median portion then less distinct and discontinuous till fore angles, fore angles gently truncate, disc covered by impressed comma-shaped punctures, sides covered by dense large relatively shallow horseshoe-shaped punctures, with opening oriented outwards. Each puncture bearing in the middle a very short simple seta. Interpunctural distance shorter than punctural diameter. Scutellum : covered by several small impressed horseshoe-shaped. Elytra: longer than wide (W/L ratio =0.93); subrectangular (dorsal view); humeral callus indistinct but marked by the thick starting point of lateral carina forming a sharp angle (dorsal view); elytral surface convex, covered by dense (interpunctural distance much shorter than punctural diameter) relatively shallow punctation. Punctures on proximal and median third horseshoe-shaped with a broad opening directed outwards, distal third covered by dense horseshoe-shaped punctures with a short opening directed backwards. Lateral carina distinct, thick, sharp and complete, slightly sinuate (lateral view), and forming a sharp angle in correspondence with humeral area forming a right angle (dorsal view). Pseudoepileura covered by dense broad horseshoe-shaped shallow punctures with a broad opening directed towards lateral carina. Wings: flightless. Male genitalia: aedeagus (L = 0.9 mm) with parameres as in Figs 87 a-b, spiculum gastrale (L = 0.7 mm) as in Fig. 87 c .

Etymology. Latin adjective in the nominative singular, meaning “acute”, referring to the humeral area of elytra.

Distribution and habitat. Known only from the type locality in Eastern Madagascar. The area is dominated by the humid climate of the east coast, with a heavy average annual rainfall. The type series was collected by sifting leaf litter in rainforest. The vegetation cover consists of “humid forest” ( Moat & Smith 2007) also known as “moist evergreen forest” ( Goodman et al. 2018). The collecting locality falls within the protected areas “Parc National de Mananara-Nord”, more precisely within the Verezanantso- ro Massif section of the national park.

Figures

Fig. 82 – Philharmostes schweikerti sp. nov., a, dorsal view of distended paratype; b, ventral view of rolled up paratype; c, dorsal view of rolled up paratype; d, lateral view of rolled up paratype; Philharmostes acutus sp. nov., e, dorsal view of distended paratype; f, ventral view of rolled up paratype; g, dorsal view of rolled up paratype; h, lateral view of rolled up paratype.

Fig. 87 – Aedeagi and spicula gastrales, a–c, Philharmostes acutus sp. nov.; d–e, Philharmostes apterus sp. nov.; f–h, Philharmostes nelsoni sp. nov. (paratype from Col de Tanatana).