Scaphisoma poussereaui, Ivan Löbl, 2015

Ivan Löbl, 2015, Scaphisoma poussereaui sp. nov. from La Réunion (Coleoptera: Staphylinidae: Scaphidiinae), arange extension of the S. tricolor species group, Mitteilungen Der Schweizerischen Entomologischen Gesellschaft 88, pp. 367-370 : 368-370

Scaphisoma poussereaui sp. nov.

( Figs 1–3)

Holotype: ♂, La Réunion 974 Coll. J. Poussereau /Chemin de Centure Maison Boyer J.P. Souche Jamblon 19 0 2 2015 ( MNHN) .

Paratypes: 3 ♂♂, 4 ♀♀, La Réunion 974 Coll. J. Poussereau / Le Tampon 800 m maison Lebeau M. tronc grand natte 24 0 2 2015 ( CPJP, MHNG) .

Description.Male. Length 1.85–2.05 mm, width 1.27–1.46 mm. Head, mouthparts, antennae, pronotum, hypomera, and tarsi ochreous. Anterior two thirds of elytra dark brown to blackish, apical third of elytra yellowish. Mesoventrite and metaventrite with epimera and anepisterna reddish-brown. Coxae, femora, tibiae and abdomen light brown, slightly lighter than metaventrite. Antennae with relative length/width of antennomeres as: III 13 / 8: IV 50 / 9: V 73 / 9: VI 60 / 10: VII 65 / 12: VIII 56 / 9: IX 68 / 12: X 65 / 15: XI 68 / 14. Pronotum and elytra not microsculptured. Pronotum with lateral margins evenly rounded, lateral margin carinae not visible in dorsal view, lateral striae very densely and distinctly punctate, disc with very fine and fairly dense punctation. Hypomera not microsculptured, with punctation very fine, hardly visible at 25 times magnification. Exposed part of scutellum fairly large, about 0.05 mm long. Elytra with lateral margins evenly rounded, lateral carinae in dorsal view concealed near bases, exposed posterior basal fourth to third; lateral striae very densely and fairly coarsely punctate; apical margins rounded, indistinctly crenulated near inner angles, inner apical angles situated posterior level of outer apical angles; sutural margins not raised, sutural striae fairly shallow, starting posterior to level of scutellar tip, subparallel; adsutural areas flat, with single puncture row; discal punctation of elytra dense and coarse except on yellowish apical area, fairly irregular, with punctures distinctly delimited, puncture intervals mostly distinctly larger than puncture diameters; punctation on light apical area very fine. Hind wings appearing fully developed. Mesanepisterna not microsculptured. Mesepimera as interval to mesocoxae and about 3 times as long as wide. Metaventrite with strigulate microsculpture; punctation very fine, distinct punctures in impressed antecoxal rows and punctures bordering submesocoxal lines excepted; punctures also fairly coarse on small areas near inner margin of metacoxae. Middle part of metaventrite convex, shallowly impressed apically. Submesocoxal lines parallel, submesocoxal areas about 0.03 mm long, about as sixth of interval to metacoxae. Metanepisterna convex, impressed toward suture, below level of metaventrite along suture, narrowed anteriad, with margin mostly oblique, rounded near anterior angles. Protibiae and metatibiae straight, mesotibiae distinctly curved posterior between basal third and apex, about as thick as protibiae, thicker than metatibiae. Protarsomeres 1 strongly widened, about as wide as apices of protibiae. Protarsomeres 2 and 3 much narrower than protarsomere 1. Mesotarsomeres 1 strongly widened, wider than apices of tibiae. Mesotarsomere 2 slightly narrower than 1, mesotarsomeres 3 weakly widened. Abdomen with strigulate microsculpture, very finely punctate except on anarrow area posterior to the intercoxal process and at margins of submetaxocal line. Submetacoxal lines convex, submetacoxal areas 0.06 mm, almost as third of interval to apical margin of sternite 1. Sternite 6 flattened in middle, extended apically to form large, broadly rounded lobe. Aedeagus ( Figs 1–3) 1.28 mm long. Basal bulb weakly sclerotized. Ventral branch of apical process of median lobe strongly inflexed lateroventrally, somewhat flattened, weakly narrowed toward tip in dorsal view. Parameres each with large and strongly sclerotized subbasal apophyses bearing membranous lobe. Internal sac with proximal, strongly bent, large tooth joined to moderately sclerotized area bearing three rods; apical part of internal sac very densely and very finely denticulate.

Female. With most characters as in male, but: Pronotum slightly lighter than or as dark as anterior two thirds of elytra. Apical elytral margins almost oblique, with inner angles slightly prominent, tooth-like and very finely crenulated. Mesotibiae weakly bent, about as thick as metatibiae. All tarsomeres narrow. Sternite 6 not lobed.

Etymology.The new species is named in honour of its collector, Jacques Poussereau., Dax, France

Comments.The species is amember of the S. tricolor group defined in Löbl (1975: 272) containing the following species: S. affectum Löbl, 2015, S. aspectum Löbl, 2015, S. borneense Pic, 1916, S. chujoi Löbl, 1982, S. hajeki Löbl, 2012, S. luctans Löbl, 1986, S. maculiger Löbl, 1875, S. renominatum Löbl, 1975, S. tarsale Löbl, 2015, S. testaceomaculatum (Pic, 1915) and S. tricolor Heller, 1917. Two additional species, S. dentipenne Löbl, 1971 and S. philippinense Oberthür, 1883, known only from females, may also be members of the group. The group was defined mainly by having conspicuously large aedeagi with moderately sclerotized basal bulb, usually bearing aventral ridge supporting robust external muscles, the apical process of median lobe is bifid, strongly sclerotized and asymmetrical, the parameres are complex and the expanded membranous apex is supported by strongly sclerotized apophyses, and the internal sac is complex, often containing a curved proximal tooth. The species of the S. tricolor group have comparatively large bodies, long antennae, the metaventrite with antecoxal puncture rows, the abdominal microsculpture strigulate, the male sternite 6 with alarge, broadly rounded lobe. Having shortened sutural striae of the elytra is another diagnostic feature for some species and in anumber of examined undescribed Philippine species (the striae are elongate in S. affectum, S. aspectum, S. chujoi, S. hajeki, S. maculiger and S. testaceomaculatum). The apical margins of the elytra are sexually dimorphic for some species, and males may also differ from females by their pronotal coloration. Scaphisoma poussereaui is readily distinguished from all members of the group by its elytral coloration and the aedeagal characters, in particular by the shape of the ventral branch of the apical process inflexed strongly ventrolaterally. In addition to these characters, S. poussereaui may be easily distinguished from its Mascarene congeners by the elytra with short sutural striae.