Charaea metallicum ( Jacoby, 1894 ) Bezděk, 2024

Bezděk, Jan, 2024, The identity of Luperus metallicus Jacoby, 1894 (Coleoptera: Chrysomelidae: Galerucinae), Zootaxa 5496 (2), pp. 295-300 : 296-299

Charaea metallicum ( Jacoby, 1894) , comb. nov.

( Figs 1–12 )

Luperus metallicus Jacoby, 1894: 308 (original description); Weise 1924: 121 (catalogue); Wilcox 1973: 624 (catalogue); Kimoto 1990: 205 (checklist); Mohamedsaid 2009: 62, 91 (checklist).

Type locality. “Sumbawa”.

Type material examined. Syntypes: 1 ♂ ( NHMUK, Figs 1–2 ), “Type / H. T. [w, p, round label with red collar] // Sumbawa / Doherty [w, h] // Jacoby Coll. / 1909-28a. [w, p] // Luperus / metallicus / Jac. [b, h] // SYN- / TYPE [w, p, round label with blue collar]”; 1 ♀ ( NHMUK), “ Sumbawa / Doherty [w, h] // Jacoby Coll . / 1909–28a. [w, p] // SYN- / TYPE [w, p, round label with blue collar]”.

Additional material examined. 12 specimens — INDONESIA: Adonara: Adonara , 1 ♀, without additional data ( MCZ, photograph examined) . Bali: road Seririt—Pupuan , 550 m, 29.–31.i.1998, 3 ♂♂, R. Červenka leg. ( JBCB) . Timor: Timor , 1 ♀, Doherty leg. ( NHMUK) ; Buraen , 50 km S of Kupang, 26.i.–9.ii.2006, 4 ♂♂ 6 ♀♀, S. Jakl leg. (3 ♂♂ 2 ♀♀ in RBCN, 1 ♂ 4 ♀♀ in UHCB) .

Redescription. Body oval, moderately convex. Color: head metallic greenish violet, labrum black, genae brownish black, mouthparts brown to black, pronotum greenish violet, elytra metallic green, often with purplish tint, pro-, meso- and metathorax metallic green, scutellum black, abdomen yellow, legs black with metallic tint, knees brownish, antennomere I brownish black, II–III dark brown, IV–XI black. Body length of males: 4.8–5.8 mm, females: 5.1–6.0 mm.

Male ( Figs 1, 3, 5 ). Labrum transverse, with rounded anterior angles, surface with six pores bearing pale seta. Anterior part of head subtriangular, convex, almost impunctate, lustrous, with four long setae along anterior margin. Interantennal space 1.3 times as wide as transverse diameter of antennal socket. Frontal tubercles ( Figs 4, 6 ) in form of oblique irregular quadrilaterals, connected, convex, lustrous, glabrous, impunctate, anterior tips divergent, separated by nasal keel. Interocular space wide, 2.2 times as wide as transverse diameter of eye. Vertex lustrous, impunctate, with distinct puncture bearing long seta behind posterior margin of each eye. Antennae thin, 0.60 times as long as body, length ratio of antennomeres I to XI: 100-55-78-122-110-110-122-122-122-122-189 (100 = 0.25 mm).

Pronotum lustrous, 1.25 times as broad as long, widest in anterior third, moderately convex, surface covered with mixture of larger and smaller punctures, larger punctures disappearing on lateral sides and in middle of pronotal surface. Anterior margin straight, unbordered, with rounded lateral margins, more bent anteriorly than posteriorly, with broad border, posterior margin widely rounded, thinly bordered. Anterior angles slightly swollen, posterior angles obtusangulate, pointed.All angles with setigerous pore bearing long pale seta. Lateral margins with additional several short setae. Scutellum subtriangular with widely rounded apex, impunctate, glabrous.

Elytra 1.35 times as long as wide, 0.70 times as long as body, widest at posterior third, surface glabrous, densely covered with fine small confused punctures and several indistinct longitudinal ribs visible on apical slopes. Humeral calli well developed. Epipleura impunctate, wide basally, narrowed in middle part and gradually narrowing towards apex. Macropterous.

Anterior coxal cavities opened posteriorly. Prosternal process not elevated between procoxae but thinly visible. Last abdominal ventrite with two short V-shaped incisions on posterior margin, middle lobe slightly impressed, with straight posterior margin.

Legs slender, densely covered with short pale setae. All tibiae with apical spine. Length ratio of protarsomeres I–III and V equals 100-90-60-120 (100 = 0.25 mm), protarsomere I triangular, as wide as II, length ratio of metatarsomeres I–III and V equals 100-83-59-116 (100 = 0.30 mm), metatarsomere I elongate, subparallel, II triangular. Claws appendiculate.

Aedeagus ( Figs 7–8 ) symmetrical, 3.25 times as long as wide, apical half wide, subparallel, basal half gradually narrowed, apex transversely cut with shallow emargination. In lateral view, aedeagus finger-shaped, widest at apical third with slightly bent apex. Internal sac ( Fig. 9 ) with two long clavate sclerites covered with small spines, and with third long sclerite distinctly sinuate in lateral view, membranous parts densely covered with setae of various lengths.

Female. Last abdominal ventrite entire, subtriangular with rounded apex.Spermatheca narrow, cornu moderately bent, nodulus not developed ( Fig. 12 ). Sternite VIII spade-shaped, with short setae on oblique posterior margins, surface glabrous, tignum 1.45 times as long as sternite VIII, slightly bent ( Fig. 11 ).

Variability. The three males from Bali ( Figs 5–6 ) slightly differ from the specimens taken from other islands in the color of their dorsal side (metallic green without violet tint) and the shape of aedeagus (the emargination on the apex is shallower and in the lateral view the aedeagus is widest in the middle) ( Fig. 10 ). However, in my opinion, these differencies do not support a separate species.

Distribution. The Sunda Islands of Indonesia (Sumbawa, Bali, Adonara, Timor).

Differential diagnosis. Charaea metallicum is similar to Ch. fruhstorferi Bezděk, 2023 from Java and Bali. Charaea fruhstorferi is characterized by a metallic green dorsal side, the elytral surface with dense punctures prone to wrinkles and covered with dense setae, and the aedeagus with an apex that is widely subtriangular with a rounded tip (see the figures in Bezděk 2023a) as opposed to Ch. metallicum which has a greenish violet pronotum and metallic green elytra with a purplish tint (except the specimens from Bali), almost glabrous elytra covered with much finer confused punctures that do not form wrinkles, and an aedeagus whose apex has a transverse cut with shallow emargination ( Figs 7–8 ). Also, the structure of spermatheca of the Ch. metallicum , with its relatively narrow cornu and undeveloped nodulus ( Fig. 12 ) is similar to that of Ch. fruhstorferi .

Remark. The female from Adonara Island deposited in the MCZ, labelled as type, does not belong to the type series of Luperus metallicus described from Sumbawa only.

Figures

FIGURES 1–6. Charaea metallicum (Jacoby, 1894). 1—syntype, male, dorsal view, 4.8 mm; 2—syntype, labels; 3—male from Timor, dorsal view, 5.2 mm; 4—male from Timor, head and pronotum; 5—male from Bali, dorsal view, 5.6 mm; 6—male from Bali, head and pronotum.

FIGURES 7–12. Charaea metallicum (Jacoby, 1894). 7—penis in dorsal, lateral and ventral views (male from Timor); 8—penis in dorsal, lateral and ventral views, drawing (male from Timor); 9—penis with everted internal sclerites in dorsal, lateral and ventral views (male from Timor); 10—penis in dorsal, lateral and ventral views, drawing (male from Bali); 11—sternite VIII; 12—spermatheca. Scale bars: 1 mm for Figs 7–11, 0.5 mm for Fig. 12.