Baconia violacea (Marseul, 1853)

Caterino, Michael S. & Tishechkin, Alexey K., 2013, A systematic revision of Baconia Lewis (Coleoptera, Histeridae, Exosternini), ZooKeys 343, pp. 1-297 : 70-72

Baconia violacea (Marseul, 1853) Fig 16FMap 5

Phelister violaceus Marseul, 1853: 469; Phelister violaris Marseul 1857: 457 (emend.). Baconia violacea : Mazur 1984: 281.

Type locality.

NOUVELLE GRENADE [including parts of Colombia and Venzuela; exact locality uncertain].

Type material.

Lectotype, sex undetermined, here designated (MNHN): "Phelister violaris M., N. Gren. … [illegible]" / “TYPE” / "Museum Paris Coll. de Marseul 2842-90" / "LECTOTYPE Phelister violaceus Marseul, 1853, M.S.Caterino & A.K.Tishechkin des. 2010".

Marseul’s poor labeling and inconsistent writings leave considerable room for question about the original identities of this and the following species. The specimen we designate as lectotype of Phelister violaceus is not labeled with that name anywhere, but only with 'Phelister violaris’, a nomen nudum that Marseul accidentally used in subsequent publications, referring evidently to this species. However, the specimen we designate as lectotype of Phelister varicolor has both violaris and violaceus on the original data label, and ‘varicolor’ only on a secondary label, which does not look exactly like Marseul’s handwriting. The type localities for the two are identical (though vague), and no other identifying data is given in the publication (though the labels are not otherwise identical). In addition the species are extremely similar and not adequately distinguished by the original descriptions. Our interpretation is that all the specimens were originally designated as violaris (at the time presumably only a manuscript name), that for the publication Marseul emended that to violaceus, and that several years later he decided that one of the original violaceus specimens was distinct and was named as varicolor (with a separate label applied at that time.) We have no strong evidence for this, however, and must admit that we cannot be certain which specimens went with which name. Our lectotype designations will help to alleviate this ambiguity.

Diagnostic description.

Length: [not measured, ~2.3mm], width: [not measured, ~1.5mm]; body elongate oval, weakly depressed, glabrous; dorsum metallic, nonuniformly in lectotype, with head, pronotum and pygidia metallic blue, elytra contrastingly bronzy-violet, venter rufobrunneus to faintly metallic; frons elevated over antennal bases, rather strongly depressed along antero-posterior midline, ground punctation rather conspicuous, with moderately large secondary punctures within frontal depression, frontal stria present along inner margin of eye, complete across front; antennal scape short, club rounded; epistoma slightly convex along apical margin, truncate to weakly emarginate; labrum about 3 ×wider than long, weakly emarginate along apical margin; pronotal sides rather strongly convergently arcuate to apex, depressed in anterior corners, marginal stria complete along lateral and anterior margins, lateral submarginal stria absent, ground punctation of pronotal disk rather conspicuous, interspersed with small secondary punctures across front and toward sides; elytra with three complete epipleural striae, outer subhumeral stria absent, inner subhumeral stria present at base, dorsal striae 1-4 complete, 5th stria absent, sutural stria more or less complete, elytral disk with very few coarse punctures in apical fifth; prosternum rather narrow, weakly convex, keel shallowly emarginate at base, carinal striae complete, divergent anterad and posterad, separate throughout; prosternal lobe about one-half keel length, apical margin bluntly rounded, marginal stria nearly complete; mesoventrite produced at middle, marginal stria complete, mesometaventral stria complete, transverse, finely crenulate, meeting lateral metaventral stria, which curves posterolaterad toward middle of metacoxa, outer lateral metaventral stria short, oblique, metaventral disk impunctate at middle; abdominal ventrite 1 with single lateral stria, slightly abbreviated apically, middle portion of disk impunctate; protibia 4 dentate, basal denticle weak, outer margin serrulate between teeth; mesotibia with two marginal spines; outer metatibial margin smooth; propygidium without basal stria, discal punctures rather small, ocellate, denser in basal two-thirds; propygidial gland openings inconspicuous; pygidium with ground punctation interspersed with small secondary punctures throughout, denser basad. Male genitalia: not known.

Remarks.

As delineated here, the only distinctive characteristics of Baconia violacea are the pattern of elytral striae, with 1-4 and the sutural striae complete (Fig. 16F), the complete frontal stria, and the presence of a fine, transverse mesometaventral stria. In Baconia varicolor , the sutural stria is abbreviated from the base, the frontal stria is interrupted at the middle, and the mesometaventral stria is subangulately arched forward at the middle. The coloration of the lectotype of Baconia violacea is distinctive, but it is impossible to know how consistent that might be. Lewis (1888) reported this species from Guatemala in the BCA. However, we assign those specimens to Baconia varicolor .