Platygeniops elongatus Jákl & Krikken, 2011

Jákl, Stanislav & Krikken, Jan, 2011, Description of a second species in the enigmatic Southeast Asian genus Platygeniops (Coleoptera: Scarabaeidae: Cetoniinae), Zootaxa 3003, pp. 63-68 : 65-68

Platygeniops elongatus Jákl & Krikken , new species

( Figs. 1–7 )

Material examined. Holotype, male (deposited in NMCP, ex CSJP), S BURMA: Tenasserim, 13 May 1994. Paratypes: W MALAYSIA: 19 miles, Cameron Highlands, May 1997 (male, RMNH); S THAILAND: Mt. Muan Chone, May 1999, Kumpuan (female, CMFT).

Diagnosis. The color pattern of the new species, with its brick-red pronotum, scutellum, and elytra, differs from the unicolored black Platygeniops exspectans . Platygeniops elongatus is much more slender and dorsoventrally distinctly complanate. The light brown pilosity of P. elongatus is dense on the posterior declivities of the elytra and on the pygidium, in contrast to the virtually glabrous dorsum of P. exspectans . The comparatively short tarsi of P. exspectans may be a female feature. There are various subtle differences in the microsculpture, and Figs. 1–3 best illustrate the shape and microsculpture of the elytra.

Description (holotype, male). Body length 33 mm. Dorsum largely brick-red, shiny, matt on densely punctatestriolate to striolate parts; head and ventral side and legs black, largely shiny; surface with complex sculpture, varying from punctate to striolate, largely glabrous, locally with numerous short, brown setae.

Clypeal margin distinctly thickened, anterior edge in full-face view bisinuate; medial surface of head slightly convex, surface behind anterolateral margin shallowly depressed; clypeolateral declivities distinct from above. Clypeofrontal surface with numerous, locally dense (sub)annular striolae. Eye canthi narrow, straight, unmodified, tip rounded. Maximum width of head capsule (including eyes) 5.9 mm, maximum width of clypeus 4.1 mm.

Pronotum with anterolateral and posterolateral angles rounded off, anterior section of lateral border slightly, evenly curvilinear in dorsal view, posterior section straight; base weakly bisinuate; disc of pronotum distinctly deplanate, anterior and lateral declivities feebly convex, black, with ridged margins (ridge along base fine, laterally interrupted). Pronotal center with scattered micropunctation only; apical, basal and lateral surfaces with multi-sized annulate-striolate punctation; punctures densely contiguous along lateral borders; some punctures with short, subappressed, pale-brown seta (length up to twice puncture diameter). Median length of pronotum (dorsal view) 8.5 mm, maximum width 10.0 mm. Scutellum impunctate on center, base with small arcuate-striolate or annulate-striolate punctures, laterally with contiguous or braided striolae.

Apart from juxtasutural striola, elytral disc with 3 low, shiny, longitudinal discal costae: broad discosutural costa (very gently sloping to suture), very narrow discomedian costa, and narrow discolateral costa; discosutural costa anteriorly broadened into almost impunctate parascutellar swelling; discosutural surface with up to 4 irregular rows of more or less confluent annulate or horseshoe-shaped striolae; most of surface around faint discomedian costa crowded with contiguous (to braided) striolae, matt. Lateral elytral declivities densely to contiguously, shallowly striolate-punctate. Posterior declivities braided-striolate, densely setose; setae (sub)erect, pale brown, mostly long, slightly curved. Epipleuron narrow in front, posthumeral-anteapical section just a narrow, slightly concave ridge (in lateral view); apical section not ridged; apicosutural angle rounded off. Sutural length of elytron (dorsal view, from scutellar apex) 15 mm, maximum humeral width of elytra combined 12.6 mm.

Antenna with 10 antennomeres, including 3 antennomere club, outer side of distal antennomere with pale grey, elongate sensorial strip. Preprosternum distinctly tectiform; postprosternum unmodified, convex. Pectoral sides densely braided-striolate in front, (horseshoe-shaped) striolate-punctate behind, abundantly setose; mesosternum somewhat smooth anteromedially, (more or less braided) striolate-setose laterally. Metasternal wings densely annulate or arcuate striolate-setose (including many horseshoe-shaped striolae, setae long), discal punctation fine. Mesepimeron distinct in dorsal view; mesepimeron and mesepisternum striolate-punctate-setose. Space separating mesocoxae narrow, not raised, with numerous long setae. Abdomen with 1+6 ventrites (basal ventrite only laterally distinct), laterally convex (in cross-section); with abundant to dense horseshoe-shaped, partly seta-bearing striolation; reflexed dorsal surface matt. Medial surface of ventrites 3–6 concave, microgranulate, matt. Pygidium broad, slightly evenly convex, almost entirely finely braided-striolate, abundantly to densely setose with some setae long; apical border finely marginate; pygidial surface black, basomedian surface rufous, all matt.

Protibia tridentate; denticles simple, acuminate; upper side densely, coarsely punctate, with many setae; underside finely, densely striolate and setose, with robust longitudinal crest, gradually lowered near apex. Terminal spur of protibia elongate-acuminate, slightly curved, apex reaching to about halfway along protarsomere 2. Mesotibiae and metatibiae striolate-setose (underside widely arcuate-striolate, upper side striolae more horseshoe-shaped); with one distinct, acuminate external elevation at about 0.25 mm from apex, particularly long on outer side of mesotibia; many setae on underside squamiform; terminal spurs long, acuminate (mesotibiae) or with slightly blunted tip (metatibiae). Femora (largely) densely arcuate-striolate setose. Metacoxa anteriorly striolate-punctate, posteriorly finely striolate. Tarsi all robust, unmodified, with large, sickle-shaped claws.

Parameres, Figs. 6–7 ; intermediate piece long, parameres dilated, outer edge (axial view) widely rounded, ending at distinct apico-internal angle (paramere width combined 3.14 mm).

Sexual dimorphism and variation. Approximate body length 28–33 mm. Male paratype similar to holotype, length 28 mm. General appearance of female similar to males; body length 30.4 mm, maximum humeral width of elytra combined 12.1 mm; punctation of head, and especially punctation of pronotum, denser than in males, diameters of punctures slightly larger. Abdominal venter of female transversely convex, lacking impression. Mesotarsi and metatarsi of female slightly shorter than in males.

Notes. The label data of the male paratype originated from an insect dealer. As such, the record from the Cameron Highlands, in our view, requires verification. The left protarsus partly missing in the holotype and was photographically mirrored from right side for the figures.

Figures

FIGURES 1 – 12. 1 – 7. Platygeniops elongatus, holotype male. 8 – 12, P. exspectans, holotype female. – Habitus oblique (1, 8), dorsal (2, 9), lateral (3, 10), ventral (4, 11), head full-face (5, 12), male genitalia, parameres (full-face, 6 – 7). For measurements see text.