Anthaxia (Merocratus) angustata Bílý, 2019

Bílý, Svatopluk & Plachetka, Mikuláš, 2019, A study on the genus Anthaxia (Merocratus) Bílý 1989 (Coleoptera: Buprestidae: Anthaxiini), Zootaxa 4701 (1), pp. 82-90 : 82-90

Anthaxia (Merocratus) angustata Bílý , sp. nov.

( Figs. 4 , 12 )

Type locality: North Vietnam, Ninh Binh province, Cuc Phuong National Park , 20°17.5727‘N 105°40.052‘E, 270 m.

Type specimen. Holotype (male, NMPC): “N-Vietnam, Ninh Binh Pr[ovince]., Cuc Phuong NP [National Park], 270 m, N20°17.5727’ E105°40.052’, 22.–25.v.2015, leg. A. Weigelˮ.

Diagnosis. Medium-sized (5.4 mm), slender, acuminate posteriorly, lustrous ( Fig. 4 ); frons metallic green, vertex black; pronotum metallic green with two large, black, more or less triangular spots narrowed posteriorly; elytra green-bronze, basal, transverse depression and small scutellar strip golden green; ventral surface, antennae and legs green, metepimera and abdominal ventrites bronze; metepimera with strip of white tomentum; entire body asetose.

Description of the male holotype. Head relatively small, partly retracted into prothorax; frons deeply, vertex weakly depressed; vertex 0.5 times as wide as width of eye; frontoclypeus anteriorly slightly rounded, weakly prognathous; eyes large, reniform, not projecting beyond outline of head; sculpture of head consisting of very small, fine, polygonal cells without central grains; antennae long almost reaching posterior pronotal angles when laid alongside; scape long, weakly claviform, about 4 times as long as wide, pedicel ovoid, 1.5 times as long as wide; third antennomere triangular, about twice as long as wide, antennomeres 4–10 trapezoidal, slightly longer than wide, terminal antennomere rhomboid, twice as long as wide.

Pronotum weakly convex, 1.7 times as wide as long, with wide, shallow lateroposterior depressions; anterior margin widely shallowly emarginate, posterior margin almost straight; lateral margins regularly rounded, posterior angles obtuse-angled, maximum pronotal width at anterior third; pronotal sculpture consisting of transversely widened cells without central grains, short, transverse, prescutellar rugae and dense, polygonal cells without central grains along lateral margins. Scutellum small, flat, microsculptured, pentagonal, as wide as long.

Elytra regularly convex and tapering posteriorly, 2.5 times as long as wide; basal, transverse depressions shallow, not reaching scutellum, humeral callosities small, only weakly projecting beyond elytral outline; subhumeral lobe large, lateral emargination wide, deep; elytral epipleura rather wide, parallel-sided, almost reaching elytral apex; lateral, preapical serrations very fine, apex of each elytron broadly rounded; elytral sculpture almost homogeneous, consisting of fine, dense, simple punctures.

Ventral surface lustrous with finely ocellate sculpture, abdominal ventrites almost glabrous; anal ventrite weakly truncate apically, slightly angulate and rather strongly serrate laterally. Legs long and slender, protibiae weakly curved, meso- and metatibiae straight, without inner serrations; tarsal claws fine, hook-shaped, not enlarged at base.

Aedeagus ( Fig. 12 ) long, slender, very weakly spindle-shaped, median lobe sharply pointed apically, without lateral serrations.

Female unknown.

Measurement: length 5.4 mm, width 2.0 mm.

Etymology. The specific epithet is derived from the Latin adjective “ angustus ˮ (slender, slim, narrow) to stress the general body-shape of the species.

Differential diagnosis. Anthaxia (Merocratus) angustata Bílý , sp. nov. belongs to the A. (M.) insulaecola species-group and it somewhat resembles by the slender body and uniformly coloured elytra A. (M.) vietnamensis ( Fig. 1 in Bílý, 1998). It differs from it by the strongly depressed frons, regularly rounded lateral, pronotal margins, shallower lateroposterior pronotal depressions, clearly limited black, pronotal spots, more acuminate elytral apices and by the long and slender aedeagus ( Figs. 12 vs. 10 in Bílý, 1998).

Distribution. Vietnam.

Figures

FIGURES 1–9. Subgen. Merocratus (dorsal view). 1—Anthaxia (M.) jakli Bílý, 1996, holotype, 6.2 mm; 2—A. (M.) miranda Deyrolle, 1864, male (Kalimantan), 5.1 mm; 3—A. (M.) miranda, female (Johor), 7.0 mm; 4—A. (M.) angustata Bílý, sp. nov., holotype, 5.4 mm; 5—A. (M.) priska Bílý, sp. nov., holotype, 4.0 mm; 6—A. (M.) priska Bílý, sp. nov., allotype, 4.6 mm; 7—A. (M.) violaceidorsis Bílý, sp. nov., holotype, 5.0 mm; 8—A. (M.) lucifera Plachetka, sp. nov., holotype, 7.0 mm; 9—A. (M.) lucifera Plachetka, sp. nov., allotype, 7.3 mm.

FIGURES 10–15. Subgen. Merocratus (aedeagi, schematically, not in scale). 10—Anthaxia (M.) jakli Bílý, 1996, holotype; 11—A. (M.) miranda Deyrolle, 1864 (Kalimantan); 12—A. (M.) angustata sp. nov., Bílý, holotype; 13—A. (M.) priska Bílý, sp. nov., holotype; 14—A. (M.) violaceidorsis Bílý, sp. nov., holotype; 15—A. (M.) lucifera Plachetka, sp. nov., holotype.