Baconia anthracina, Caterino, Michael S. & Tishechkin, Alexey K., 2013

Caterino, Michael S. & Tishechkin, Alexey K., 2013, A systematic revision of Baconia Lewis (Coleoptera, Histeridae, Exosternini), ZooKeys 343, pp. 1-297 : 99-101

Baconia anthracina sp. n. Figs 1A, E2C28 A–B29A–FMap 7

Type locality.

BOLIVIA: Santa Cruz: Flora y Fauna Hotel [17.49°S, 63.55°W].

Type material.

Holotype male: "BOLIVIA: Santa Cruz Dep. 3.7 km SSE Buena Vista, Flora y Fauna Hotel, 17°29.9'S, 63°33.2'W, 400-440m. F.I.T. 3-9 Nov 2002. R. Leschen # 054" / "Caterino/Tishechkin Exosternini Voucher EXO-00514" (SEMC). Paratypes (26): BOLIVIA: 22:Hotel Flora y Fauna, 5 km SSE Buena Vista, 17°29.9'S, 63°39.1'W, 14-24.xii.2003, FIT, S. & J. Peck (CMNC, FMNH, MSCC, AKTC), 2:24-31.xii.2003, FIT, S. & J. Peck (CMNC); 2: Santa Cruz:Amboro National Park, Los Volcanes, 18°06'S, 63°36'W, 1000 m, 20.xi-12.xii.2004, FIT, H. Mendel & M. Barclay (BMNH).

Other material.

1: BRAZIL: Mato Grosso:Mpio. Cotriguaçu, Fazenda São Nicolau, Matinha, 9°50.3'S, 58°15.05'W, 3.iv.2009, FIT, F. Vaz-de-Mello (CEMT).

Diagnostic description.

Length: 1.9-2.1mm, width: 1.7-2.0mm; body rather broadly elongate oval, convex, glabrous; piceous, shining; frons elevated over antennal bases, depressed in middle, interocular margins convergent dorsad, frontal disk with few coarse punctures in median depression, epistoma with fairly descrete median fovea, otherwise impunctate, frontal stria present along inner edges of eyes, largely absent between antennal bases, may be represented by few median fragments; supraorbital stria absent; antennal scape short, club broadly rounded, slightly asymmetrical; labrum with upper edge weakly carinate, emarginate, distal margin narrowed, recessed between mandibles; mandibles rather short, each with small basal tooth; pronotal sides evenly narrowed in basal two-thirds, more strongly arcuate to apices, lateral marginal striae continuous around sides and front, submarginal stria absent, anterior corners of pronotal disk weakly depressed, coarser secondary punctures of pronotal disk present only in lateral fourths; elytra with two complete epipleural striae, outer subhumeral stria absent, inner subhumeral stria present as short basal fragment, dorsal striae 1-2 more or less complete, 3rd stria vaguely present in basal half, fragmented and scratchlike, 4th stria present as very short basal arch, 5th stria absent, sutural stria present for short distance at middle, not meeting basal arch of 4th, elytral disk with small, sparse punctures in apical fourth; prosternal keel moderately broad, weakly convex, emarginate at base, carinal striae convergent between coxae, diverging anterad and posterad, complete, free; prosternal lobe short, about one-third keel length, apical margin rounded, marginal stria well impressed at middle, obsolete at sides; mesoventrite weakly produced at middle, marginal stria complete; mesometaventral stria weakly arched at middle, crenulate; base of inner lateral metaventral stria displaced slightly mediad, curving obliquely posterolaterad toward middle of hind coxa, slightly abbreviated at apex, outer lateral metaventral stria subparallel, about half as long as inner; metaventral and abdominal disks impunctate at middle; abdominal ventrite 1 with inner lateral stria nearly complete, outer lateral stria absent; protibiae 4-dentate, outer margin finely serrulate; mesotibia with one marginal spine; outer metatibial margin smooth; propygidium lacking basal stria, with coarse secondary punctures more or less uniformly separated by about their diameters, smaller and denser along basal margin, propygidial glands visible about one-fifth from basal margin, one-fourth from lateral margin; pygidium with fine ground punctation very sparsely interspersed with small secondary punctures, predominantly along basal margin. Male genitalia (Figs 29 A–F): T8 about as long as broad, widest at middle, sides outwardly arcuate, basal emargination deep, subacute at middle, basal rim well sclerotized, apex narrowly emarginate, ventrolateral apodemes projecting weakly beneath, about one-third from base, separated by about two-thirds maximum T8 width, rapidly narrowed apically; S8 divided, inner margins approximate only at base, divergent apically, outer margins weakly rounded, slightly convergent, apical guides slightly widened distally, narrowly rounded at apices, apical velar membrane absent, apex lacking conspicuous setae; T9 with basal apodemes rather thin and elongate, nearly one-half total length, T9 apices narrowly rounded, glabrous, ventrolateral apodemes weakly projecting beneath; S9 rather broad, with stem weakly narrowed near midpoint, base rounded, apex expanded, apical emargination broadly subtriangular, broadly desclerotized along midline; tegmen with sides subparallel, weakly narrowed to blunt apices, tegmen in lateral aspect more or less straight, weakly curved ventrad at tip; median lobe simple, about one-half tegmen length; basal piece short, about one-fourth tegmen length.

Remarks.

This species can be distinguished by its unique epistomal fovea (Figs 1A, 28A), a discrete depression immediately anterad, and sometimes continuing, the frontal depression. It is otherwise very similar to Baconia salobrus , having an isolated basal arch of the 4th stria (Fig. 28B). The following species, Baconia emarginata , is also similar to both of these, but is easily recognized by its deeply emarginate labrum and generally large head and mandibles.

Etymology.

This species’ name refers to its black coloration.