Charaea Baly, 1878

Bezděk, Jan & Lee, Chi-Feng, 2014, Revision of Charaea (Coleoptera: Chrysomelidae: Galerucinae) from Taiwan, Zootaxa 3861 (1), pp. 1-39 : 3-4

Genus Charaea Baly, 1878

Charaea Baly, 1878: 376 (type species Charaea flaviventre Baly, 1878 , by monotypy [currently Ch. balyi ( Medvedev & Sprecher-Uebersax, 1998) , a replacement name for homonymous Charaea flaviventre Baly, 1878 , nec Calomicrus flaviventris Motschulsky, 1860 , both in Charaea now]); Maulik, 1936: 300; Wilcox, 1973: 449 (catalogue); Seeno & Wilcox, 1982: 109; Medvedev & Sprecher-Uebersax, 1998: 32 ( Charaea synonymized with Calomicrus ); Kimoto, 2004: 52; Beenen & Lee, 2010: 258 ( Charaea has priority over Taphinellina ); Beenen & Warchałowski, 2010: 61 –62 (catalogue); Beenen, 2011: 50 ( Charaea has priority over Taphinellina ).

Charoea [sic!]: Baly, 1890: 30 (duplicate description).

Taphinellina Maulik, 1936: 299 (type species Taphinella bengalensis Jacoby, 1900 , by original designation); Wilcox, 1973: 449 (catalogue); Seeno & Wilcox, 1982: 109; Beenen, 2010: 75 (synonymized with Charaea ), 488 (catalogue); Warchałowski, 2010: 717.

Description. Coloration: dorsum lustrous, metallic blue, green or bluish-black, rarely brown with metallic tint. Antennae black, rarely brown. Legs metallic or black, in some species with paler knees. Ventral side metallic or black, abdomen yellow, black or bicolorous.

Head impunctate, lustrous, nearly glabrous. Labrum transverse, with six pores in transverse row bearing pale seta, with rounded lateral margins, anterior margin slightly emarginate. Anterior part of head impunctate, glabrous or with sparse setae on anterior margin of clypeus and along lateral margins of nasal keel. Nasal keel wide, slightly convergent posteriorly, moderately convex. Frontal tubercles large, triangular or transversely subtriangular, elevated, lustrous, glabrous, impunctate, anterior tips divergent, separated by nasal keel. Vertex separated from frontal tubercles by deep furrow, impunctate, with shallow impression in middle just behind furrow, behind each eye with setigerous pore bearing long seta. Antennae filiform (very rarely with some antennomeres extended and modified), 0.55–0.80 as long as body, antennomeres I–III lustrous, covered with sparse setae, antennomeres IV–XI dull, covered with dense setae.

Pronotum lustrous, 1.20–1.40 times as broad as long, usually widest in anterior third, moderately to strongly convex, covered with fine punctures. All margins bordered, anterior margin with very fine border, lateral margins with broad border. All angles with setigerous pore bearing long pale seta.

Scutellum subtriangular, impunctate, glabrous, with rounded apex.

Elytra ca 1.35–1.80 times as long as wide and 0.65–0.80 times as long as body, almost glabrous (usually with almost indistinct very scarse short pale setae on lateral and apical slopes), widest behind middle, densely covered with fine small confused punctures. Humeral calli well developed. Epipleura impunctate, wide in basal third, then suddenly narrowed, gradually narrowing in apical two thirds and disappearing before apex. Macropterous.

Ventral surface subopaque, sparsely covered with fine punctures and pale setae. Abdomen simple, last ventrite transverse, posterior margin with two short incisions.

Anterior coxal cavities opened posteriorly. Prosternal process either invisible between procoxae, thinly visible but not elevated, or visible and elevated between procoxae.

Legs slender. All tibiae with apical spur in both sexes. Tarsomeres I elongate, slender, moderately widened to apex, as wide as tarsomeres II. Claws appendiculate.

Aedeagus symmetrical, tubular or subtubular, ventroapical part rounded or produced to various, often bent process. Internal sac with three sclerites: one median, ventral, usually slender and shorter, pair of dorsal sclerites, flat, of various length, connected basally and usually longer than median sclerite, rarely lateral sclerites missing (in such case median sclerite long—e. g. Ch. miyamotoi or Ch. haruoi sp. nov.), internal sac often forms complicate setose structures of various length of setae, often cummulated to brush-like clusters.

Spermatheca with poorly delimited nodulus, only slightly wider than cornu, proximal spermathecal duct widened in basal part. Sternite VIII subtriangular or subquadrangular, apical margin often with short setae, disc glabrous or with sparse longer setae. Tignum thin, 2.0–4.0 times longer than sternite VIII.

Differential diagnosis. Although many Charaea species were originally described in genera Calomicrus and Exosoma , the three genera are not separable based on consistent characters. Calomicrus is evidently polyphyletic in current concept and requires comprehensive revision. However, the coloration of Calomicrus species is rather variable, but very rarely completely metallic blue, the prosternum is not visible between procoxae, procoxal cavities open or closed, one or two pairs of bursa sclerites present, and the aedeagus is variable in shape but the internal sac has a different structural anatomy.

Exosoma species occur in Europe and North Africa and are larger (6–10 mm), with dorsum never completely metallic (always at least pronotum orange or red).

In habitus and body length, the genus Charaea is similar to Erganoides Jacoby, 1903 . The representatives of Erganoides are characterised by very unusual structure of aedeagus (compare with drawings in Gressitt & Kimoto 1963 or Beenen & Lee 2010). The coloration of dorsum in Erganoides is variable but usually at least partly pale in comparison with uniform completely metallic dorsum in Charaea .

Biology. Host plants are unknown. The adults are evidently floricolous as observed in most of Taiwanese species. Several specimens were also collected after dark at lights.

Distribution. China, Japan, Taiwan, Himalayas and India, northernmost to Siberia and Mongolia, south to Vietnam, Laos, Thailand and continental Malaysia.