Anthaxia (Anthaxia) ungulata, Bílý, Svatopluk, 2015

Bílý, Svatopluk, 2015, Two new species of the genus Anthaxia (Anthaxia Eschscholtz 1829) from China, and notes on the related species (Coleoptera: Buprestidae: Anthaxiini), Zootaxa 3964 (4), pp. 482-488 : 487-488

Anthaxia (Anthaxia) ungulata sp. nov.

( Figs. 7, 8, 9 )

Type locality. China, northern Sichuan, Nanjiang.

Type specimens. Holotype (male, NMPC): “ China, N Sichuan, Nanjiang, 29.v.2002, E. Kučera leg.”; allotype (female, EKCS): the same data; paratype (female, EKCS): the same data.

Diagnosis. Medium-sized (4.2–4.5 mm), strongly convex, matt with silky lustre, elongate-ovate ( Fig. 7 ); head golden green with black vertex, pronotum golden green with wide, black, medial, longitudinal stripe, posterior angles with golden reflections; elytra and scutellum blue-green, antennae and anterior legs golden green, middle and posterior legs black with green lustre; outer angles of antennomeres 8–11 brown; ventral surface blue-green, lustrous; dorsal surface asetose; frons with very short, sparse, almost indistinct, white pubescence; ventral surface with very short, sparse, white, recumbent pubescence.

Description of the male holotype. Head large, distinctly wider than anterior pronotal margin; frontoclypeus trapezoidal, not separated from frons, anterior margin triangularly emarginate; frons wide, regularly convex, vertex slightly convex, twice as wide as width of eye; eyes large, reniform to elliptical, slightly projecting beyond outline of head; antennae relatively long reaching posterior fifth of lateral pronotal margins when laid alongside; scape pyriform, almost 3 times as long as wide, pedicel ovoid, 1.5 times as long as wide, third antennomere slightly triangular, 1.3 times as long as wide; antennomeres 4–10 trapezoidal, about as long as wide, terminal antennomere rhomboidal, 1.8 times as long as wide; sculpture of head consisting of very small and dense, irregular, polygonal cells with tiny central grains.

Pronotum convex, much narrower than elytra, 1.4 times as wide as long, with large, deep laterobasal depressions, maximum width at anterior third; lateral margins S-shaped, posterior angles almost rectangular; anterior margin deeply bisinuate, median lobe strongly projecting anteriorly, posterior margin very weakly bisinuate, almost straight; sculpture consisting of coarse, irregular polygonal cells with large central grains on lateral parts of pronotum, medially (on black stripe) without distinct grains. Scutellum small, flat, triangular to cordiform, slightly wider than long.

Elytra regularly convex, conspicuously enlarged at posterior third, elongate-ovate, twice as long as wide (at posterior third); humeral callosities very small; transverse, basal depression very weak, almost missing; elytral apices separately rounded, with very fine, almost indistinct lateral serrations at extreme apex; elytral epipleura very narrow, not reaching elytral apex; sculpture almost homogeneous consisting of basal microsculpture and fine, simple punctures denser on basal portion of elytra.

Ventral surface lustrous, with fine cellular sculpture abdominal ventrites almost glabrous; anal ventrite obtusely rounded, without lateral serrations.

Legs long and slender, mesotibiae almost straight, weakly, regularly enlarged apically, with several very small, preapical teeth on inner margin; metatibiae flattened, slightly S-shaped and enlarged apically, with fine, preapical serrations on inner margin; all tarsi very slender, almost as long as corresponding tibiae; tarsal claws relatively large, strongly hook-shaped, with large, basal tooth ( Fig. 9 ).

Aedeagus ( Fig. 8 ) short and rather robust, parameres abruptly narrowed at apical two fifths, narrowed portion very weakly sclerotised; median lobe narrow, sharply pointed, without lateral serrations.

Measurements. Length: 4.2–4.9 mm (holotype 4.3 mm); width: 0.9–1.1 mm (holotype 0.9 mm).

Sexual dimorphism. The female differs from the male by the black medial portion of frons (reaching from the vertex to the frontoclypeus), less intense golden lustre of posterior pronotal angles, blue elytra, wider vertex (2.3 times as wide as width of eye) and by the simple, straight meso- and metatibiae.

Variability. No substantial variability was found among three specimens except for the sexual dimorphism and size (see above); paratype possesses slightly wider pronotum (1.5 times as wide as long).

Etymology. The specific epithet is derived from the Latin substantive “ ungulum ” (claw, talon) to stress the unusual shape of the tarsal claws.

Bionomy. All three type specimens were collected on the young, terminal parts of branches of Quercus sp. ( Fagaceae ), but the host plant is unknown.

Differential diagnosis. Anthaxia (A.) ungulata sp. nov. resembles very much by its size, body-shape and colouration the European species, A. (A.) tuerki Ganglbauer, 1886 from which it differs (except for the distribution) by the more strongly convex frons, more posteriorly narrowed pronotum, widely enlarged, ovate elytra, different pronotal and elytral sculpture, form of male meso- and metatibiae (straight and unarmed in A. (A.) tuerki ), shape of the male genitalia and, of course, by the most important diagnostic character: tarsal claws with large, basal tooth ( Fig. 9 ). This, most probably an adaptive, character is very rare in the genus Anthaxia and is so far recorded only in the A. (Haplanthaxia) collaris Kerremans, 1893 species-group ( Bílý, 1995b) and in some African species ( A. (H.) gussmannae Bílý, 2002 ). This is the first record of the tarsal claws with the basal tooth in the subgenus Anthaxia s. str.

Anthaxia (A.) ungulata sp. nov. also slightly resembles by the form of pronotum the nearly sympatric species A. (A.) constricticollis Bílý, 2007 from Shanxi ( Fig. 6 ). The latter differs from A. (A.) ungulata sp. nov. by the larger body, less enlarged elytra, narrower vertex (almost as wide as width of eye), unmodified male tibiae, quite different male genitalia ( Fig. 7 in Bílý 2007) and significantly by the simple tarsal claws.

Figures

FIGURES 6 – 9. 6 — Anthaxia (A.) constricticollis Bílý, 2007, holotype, 5.7 mm; 7 — A. (A.) ungulata sp. n ov., holotype, 4.3 mm; 8 — the same, aedeagus, 1.3 mm; 9 — the same, tarsal claws of mesotarsus (length of tarsus 0.7 mm).