Phaedis nagaii, 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 : 527-528

Phaedis nagaii sp. nov.

( Figs 17 , 24–29 )

Type specimen. Holotype: ♂, Malaysia, Telupid, alt. 800 m, 80 km East from Ranau, Sabah, Borneo , 23.IV.1979, Shinji Nagai leg. ( EUMJ).

Description. Male. Body length: 10.5 mm. Oblong, gently convex above, shiny. Colour dark reddish brown; head, pronotum greenish blue; elytra metallic green, reddish purple on sutural portions, the metallic green colour easily changing into purple in angles of view; mouthparts paler; venter with metallic green sheen.

Head semicircular, weakly convex posteriorly, distinctly microsculptured, with punctures piligerous; mCG not sinuate; epistoma almost flat, roundly produced, faintly emarginate at apex in median half, finely and densely punctate; frontoclypeal suture tenuous but distinct, not angulate at posterior corners; genae strongly depressed, elevated laterally, finely punctate as those on epistoma; tempora convex, obliquely convergent posteriad, not produced, with coarse punctures; frons broad, depressed, never elevated along inner ocular-sulci, with punctures very sparse, sparser, finer than on epistoma; IE/TD 2.50; eyes coarsely facetted, moderately convex, with inner ocular sulci shallow and weak. Antennae reaching middle of pronotum; distal five antennomeres distinctly dilated, forming compact club; 11th short-oval. Ultimate maxillary palpomere large, right-angled triangular, with acute apical corners; endoapical corner rather strongly produced. Mentum triangular ( Fig. 24 ), pointed at apex, broadly carinate in middle, deeply excavate at sides, finely microsculptured, moderately punctate.

Pronotum transversely quadrate, widest at basal fourth, with fine microsculpture; PW/PL 1.51; disc weakly convex, gently descendent laterally, depressed, not sulcate along lateral margins, densely, very finely punctate, the punctures nearly as large as on head; anterior margin weakly emarginate, finely beaded laterally; lateral margins gently rounded and narrowed before and steeply so after the widest point, not sinuate before base, narrowly beaded; basal margin gently bisinuate, thickly beaded; anterior corners obtuse, posterior ones obtusely angulate, both corners not produced. Scutellum depressed, with fine microsculpture.

Elytra oblong, distinctly convex, moderately divergent posteriorly, widest at apical third, with very fine microsculpture; EL/EW 1.56; striae weakly impressed, distinctly so on 1st ones, vestigial in part; strial punctures dense, rather fine though irregular in density, becoming smaller on apical declivity; intervals slightly convex, weakly so on apical portions of 9th ones, finely and rather densely punctate; humeral callus oblong, moderately humped; epipleura smooth though bearing very sparse and microscopic piligerous punctures, weakly oblique, without microsculpture.

Prothoracic hypomera depressed, finely microsculptured, with minute and sparse punctures. Prosternum short in front of coxae, finely microsculptured, weakly beaded at apex; prosternal process long, wedge-shaped ( Fig. 25 ), distinctly bent inward behind coxae, moderately sulcate in middle, impunctate. Mesoventral ridge V-shaped, short, horizontal, with two anterior angles obtusely rounded in lateral view, moderately produced forwards. Metaventrite gently convex, finely microsculptured, obliquely rugulose, with very fine and setiferous punctures laterally. Abdomen slightly convex in middle, finely and densely punctate, the punctures on each ventrite gradually becoming smaller posteriorly.

Aedeagus slender ( Fig. 29 ), slightly incurved; basale 1.79 times as long as parameres, weakly dilated posteriorly; parameres gently tapering towards apices, scarcely punctate.

Legs robust. Profemoral teeth distinctly curved laterad; meso- metafemora thickened towards apical third. Tibiae short and robust ( Figs 26–28 ); protibiae weakly incurved, distinctly depressed ventrally, with inner margin feebly emarginate between middle and basal fourth; mesotibiae almost straight, with inner margin roundly produced at basal fifth, densely pubescent in apical four-fifths; metatibiae slightly incurved, with inner margin roundly produced at basal fifth distinctly depressed in basal half, finely pubescent between the produced area and apex, without pubescent excavation. Tarsi simple, compactly articulate.

Female. Unknown.

Distribution. Borneo (Sabah).

Etymology. The specific epithet is cordially dedicated to the late Shinji Nagai, Kiso, famous Japanese coleopterist and collector of the holotype.

Differential diagnosis. This new species is similar in bent prosternal process, rounded elytral humeri and shape of pronotum to Phaedis purpureipennis (Pic, 1916) from Brunei, but is clearly different from the latter by the characters mentioned in the following key.

- Colour dark reddish brown; head and pronotum greenish blue; elytra metallic green, reddish purple on sutural portions, the metallic green colour easily changing into purple in angles of view; head with punctures piligerous; epistoma faintly emarginate at apex in median half; frontoclypeal suture tenuous and distinct; frons with punctures finer and very sparser than on epistoma. Pronotum widest at basal fourth, not sulcate along lateral margins, with punctures nearly as large as on frons; anterior margin weakly emarginate; lateral margins not sinuate before base. Elytra with striae weakly impressed; strial punctures dense; intervals slightly convex, weakly so on apical portions of 9th ones; humeral callus moderately humped. Prosternal process long, wedge-shaped. Mesotibiae with inner margin densely pubescent in apical four-fifths and roundly produced at basal fifth; inner margin of metatibiae without pubescent excavation............................................. P. nagaii sp. nov.

- Colour black; head and pronotum dark metallic green; elytra reddish purple throughout; head with punctures not piligerous; epistoma entirely rounded at apex; frontoclypeal suture scarcely visible, vestigial in part; frons with punctures larger and slightly sparser than on epistoma. Pronotum widest behind middle, very finely sulcate along lateral margins, with punctures larger than on frons; anterior margin arcuately emarginate; lateral margins sinuate in basal fourth. Elytra with striae vestigial; strial punctures sparse; intervals entirely flattened; humeral callus scarcely humped. Prosternal process short, lanceolate. Mesotibiae with inner margin sparsely pubescent in basal half and not produced at basal fifth; metatibiae with inner margin decorated with elongate and pubescent excavation between middle and apical sixth....................... P. purpureipennis (Pic, 1916)

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 24–29. Phaedis nagaii sp. nov.—24, mentum; 25, prosternal process; 26, protibia; 27, mesotibia; 28, metatibia; 29, aedeagus (right: in lateral view; left: in dorsal view). Scale bars: 0.3 mm for fig. 24; 0.5 mm for Figs 25–29.