Phaedis minusculus, Ruzzier & Ando, 2021

Ruzzier, Enrico & Ando, Kiyoshi, 2021, Seven new species of the genus Phaedis Pascoe, 1866 (Coleoptera: Tenebrionidae Cnodalonini) from Borneo, Zootaxa 5004 (4), pp. 521-537 : 534-536

Phaedis minusculus sp. nov.

( Figs 22 , 41–46 )

Type specimen. Holotype: ♂, Keningau , Sabah, N. Borneo, 29.V.1989, M. Itoh leg. ( EUMJ).

Description. Male. Body length: 5.0 mm. Oblong-oval, gently convex above, shiny. Colour dark reddish brown; head metallic green; pronotum dark purple, with a pair of large metallic green spots, the spots free from lateral margins of pronotum; elytra light metallic green; mouthparts paler.

Head transversely trapezoidal, with fine isodiametric microsculpture; punctures piligerous, dense, rather coarse, larger, sparser on frons and post-cephalic portion; mCG not sinuate; epistoma strongly convex, distinctly produced, gently emarginate at apex in median two-thirds; frontoclypeal suture fine, obscured by coarse punctures, rounded at posterior corners; genae flat, nearly as long as wide, not elevated laterally, with external margins roundly produced in basal half, emarginate in apical half; tempora short, weakly convex, with several coarse punctures; frons flattened, weakly sloping forwards, not elevated along eyes; IE/TD 2.42; eyes gently convex, weakly transverse in dorsal view, with inner ocular sulci deep, narrow. Antennae slender, long, reaching before base of pronotum; distal five antennomeres weakly dilated, forming somewhat loosely articulated club; 11th short-oval. Ultimate maxillary palpomere short, weakly securiform; both apical corners acute, with endo-apical corner strongly produced laterad. Mentum transversely subelliptical ( Fig. 41 ), triangularly elevated in middle, deeply excavate at sides, rounded at apex, with a few long setae anteriorly.

Pronotum quadrate, widest at middle, with fine isodiametric microsculpture; PW/PL 1.46; disc gently convex, steeply descendent laterally, feebly sulcate along lateral margins, not along basal bead, with punctures dense, coarse, distinctly larger than on head, not piligerous; anterior margin almost straight, feebly beaded except median third; lateral margins arcuate, strongly so in apical half, weakly so in basal half, not sinuate before base, narrowly beaded; basal margin finely beaded; anterior corners obtusely rounded, posterior ones obtusely angulate, not produced. Scutellum flattened, triangular, 1.25 times as wide as long, pointed at apex, almost smooth.

Elytra strongly convex, gently divergent posteriorly, widest at apical third, scarcely microsculptured; EL/EW 1.50; striae very weakly impressed or vestigial; strial punctures, coarse, sparse, rather large, denser on 1st, 8th striae, becoming rudimental in apical declivity; intervals almost flat throughout, finely, very sparsely punctate; humeral callus oval, weakly humped; epipleura unevenly flat, sparsely rugulose, finely microsculptured, impunctate.

Prothoracic hypomera slightly convex, impunctate, densely covered with fine isodiametric microsculpture. Prosternum short, cribrous in front of coxae, not beaded at apex; prosternal process wedge-shaped ( Fig. 42 ), strongly bent inwards behind coxae, deeply sulcate in middle, acutely pointed at apex, with several coarse punctures. Mesoventral ridge V-shaped, weakly sloping forwards, vermiculate, with anterior angles very obtuse, not produced in lateral view. Metaventrite distinctly convex, finely microsculptured, obliquely rugose; punctures piligerous, fine, rather dense, the hair in puncture very long satiated in median half, short in lateral portions. Abdomen rather broad, moderately convex, compactly microsculptured, densely covered with piligerous punctures.

Aedeagus slender ( Fig. 46 ); basale 1.25 times as long as parameres, moderately curved ventrad; parameres scarcely curved ventrad, impunctate, moderately rounded at sides in basal half, steeply tapering to apices in apical half, minutely bulbiform at apices.

Legs robust, moderate in length ( Figs 43–45 ). Profemoral teeth large, directed laterad at apex; posterior margins of mesofemora with a small tooth at about apical third, thence ancipital to apex; posterior margin of metafemora ancipital in apical half, with metafemoral tooth small, situated at apical two-fifths. Protibiae gently incurved, with inner margins without emargination; mesotibiae slightly incurved, with inner margin sparsely pubescent in apical half; metatibiae slender, slightly incurved, simple. Tarsi compactly articulate, densely covered with velvety pubescence on the sole.

Female. Unknown. Distribution. Borneo (Sabah). Etymology. The specific epithet refers to the small body of this new species. Differential diagnosis. This species belongs to the Phaedeucyrtus species-group, and allies in robust profemoral tooth, strial punctures, similar tooth on meso- and metafemora, and outline of elytra to Phaedis ventralis Ando, 2016 from Borneo, but is clearly separable from the latter by the characters mentioned in the following key.

- Body length 5.0 mm; IE/TD 2.42 in male; head metallic green; pronotum dark purple, with a pair of large metallic green spots; elytra metallic light green, without spots; epistoma strongly convex, gently emarginate at apex in median two-thirds; frontoclypeal suture obscure, rounded at posterior corners; mentum subelliptical, rounded at apex. Pronotum not sulcate along basal margin, with punctures distinctly larger than on head; anterior margin almost straight; lateral margins not sinuate before base. Prosternal process strongly bent inwards behind coxae; anterior angles of mesoventral ridge very obtuse, not produced in lateral view. Basal three abdominal ventrites without tuft of long pubescence in each middle. posterior margins of mesofemora without row of dense pubescence between base and mesofemoral tooth; inner margin of protibiae without emargination; inner margin of metatibiae slender, simple, without depression nor tubercle................................. P. minusculus sp. nov.

- Body length: 7.5–9.5 mm; IE/TD 1.76–2.14 in male; head and pronotum violet-purple or dark metallic green, otherwise dark blue, without spots; elytra aeneous to brassy-aeneous, greenish black in a few case; each elytron with metallic blue humeral and apical spots; epistoma weakly convex, straight at apex; frontoclypeal suture distinct, angulate at posterior corners; mentum triangular, acute at apex. Pronotum weakly sulcate along basal margin, with punctures as large as on epistoma; anterior margin weakly emarginate, slightly produced in median third; lateral margins sinuate before base. Prosternal process weakly sloping posteriad; anterior angles of mesoventral ridge produced forwards, obtusely angulate in lateral view. Basal three abdominal ventrites with sparse tuft of long pubescence in each middle. Posterior margins of mesofemora with a row of dense pubescence between base and mesofemoral tooth; inner margin of protibiae emarginate in apical three-fourths; inner margin of metatibiae strongly depressed, suddenly produced inwards just behind base, with a minute tubercle at the apical terminal of the depression near apex.......................................................................... P. ventralis Ando, 2016

Figures

FIGURES 17–23. Phaedis spp., habitus.—17, Phaedis nagaii sp. nov.; 18, Phaedis tenuifasciatus sp. nov.; 19, Phaedis fusivittatus sp. nov.; 20, Phaedis choui sp. nov.; 21, Phaedis amabilis sp. nov.; 22, Phaedis minusculus sp. nov.; 23, Phaedis dilatitarsalis sp. nov.

FIGURES 41–46. Phaedis minusculus sp. nov.—41, mentum; 42, prosternal process; 43, protibia; 44, mesotibia; 45, metatibia; 46, aedeagus (right: in lateral view; left: in dorsal view). Scale bars: 0.1 mm for fig. 41; 0.3 mm for fig. 42; 0.5 mm for Figs 43–46.