Baconia nayarita, 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 : 257-260

Baconia nayarita sp. n. Figs 80 A–B81A–FMap 22

Type locality.

MEXICO: Nayarit: Tepic [exact locality unknown]

Type material.

Holotype male: "El Cora, Tepic, Ad. Lüdecke” / "Zool. Mus. Berlin" / "Caterino/Tishechkin Exosternini Voucher EXO-00494" (ZMHB). Paratypes (3): 3: MEXICO: Nayarit: 48 km SE Tepic, 1188 m, 19.viii.1976, E. Ross (CASC, MSCC).

Diagnostic description.

Length: 2.5-2.6mm, width: 2.2-2.3mm; body elongate oval, only weakly depressed, glabrous; body coloration somewhat variable, dorsum me tallic blue to faintly greenish-blue to near violet, more or less uniform, but head and/or pronotum may appear slightly greener than elytra, venter rufopiceous; frons elevated over antennal bases, depressed along antero-posterior midline, ground punctation rather conspicuous, with few secondary punctures on epistoma, within frontal depression and near vertex, frontal stria present along inner margin of eye, curving mediad, but usually somewhat fragmented across middle, supraorbital stria may be absent or vaguely indicated; antennal scape short, club rounded; epistoma truncate to weakly emarginate; labrum about 3 ×wider than long, weakly emarginate along apical margin; both mandibles with acute basal tooth; pronotal sides weakly, evenly arcuate to apex, not depressed in anterior corners, marginal stria complete along lateral and anterior margins, slightly crenulate in front, lateral submarginal stria absent, ground punctation of pronotal disk fine, with conspicuous secondary punctures in lateral thirds, denser toward sides; elytra with three complete epipleural striae, outer subhumeral stria absent, inner subhumeral stria present at base and as median fragment (continuous in type), dorsal striae 1-3 complete, 4th stria slightly abbreviated from apex, 5th stria absent or only very weakly indicated near apex, sutural stria present in apical half to two-thirds, elytral disk with few coarse punctures in apical fifth; prosternum weakly convex, keel weakly emarginate at base, carinal striae complete, subparallel, separate throughout; prosternal lobe about one-half keel length, apical margin bluntly rounded, marginal stria obsolete at sides; mesoventrite weakly produced, marginal stria complete, mesometaventral stria absent; lateral metaventral stria extending from near mesocoxa posterolaterad toward middle of metacoxa, more or less complete, outer lateral metaventral stria parallel to inner stria for about two-thirds its length, metaventral disk impunctate at middle; abdominal ventrite 1 with inner lateral stria abbreviated, outer stria absent, middle portion of disk impunctate; protibia 4-5 dentate, basal denticles weak, outer margin serrulate between teeth; mesotibia with one marginal spine and short series of very weak submarginal spines toward base; outer metatibial margin smooth; propygidium without basal stria, discal punctures ocellate, largest basomedially, smaller and sparser posterad and laterad; propygidial gland openings evident about one-third from anterior margin and one-fourth from lateral margins; pygidium with ground punctation conspicuous, secondary punctures very small and restricted to near basal margin. Male genitalia (Fig. 81): T8 slightly longer than wide, sides subparallel, basal emargination shallow, broadly arcuate, basal rim slightly explanate, subbasal membrane attachment line evident, ventrolateral apodemes reaching longitudinal midpoint beneath, separated by about one-half T8 width, evenly tapered to apex; S8 halves approximate in basal half, inner margins rapidly diverging to apex, sides subparallel to converging slightly, apical guides narrowly developed, apices bearing a few inconspicuous setae, connected by thin ventral velar membrane; T9 with proximal apodemes short, about one-fourth total length, dorsal lobes elongate, narrowed apically, ventrolateral apodemes weakly dentate beneath; S9 desclerotized along midline, divided in apical third, stem narrow, constricted slightly at middle, apical arms divergent, apices acute; tegmen with sides very weakly widening to apex, slightly sinuate, thin, straight in lateral aspect; median lobe simple, one-third tegmen length; basal piece one-third tegmen length.

Remarks.

This species is very similar to Baconia viridis , below, even in male genitalic characters, and can best be distinguished by its larger body size, more blue-to-violet dorsal coloration (Fig. 80A), presence of the sutural elytral stria, and nearly complete frontal stria (Fig. 80B). Externally both of these species look much like members of the Baconia godmani group, but their male genitalia are quite different, lacking the conspicuous apical fringe of the 8th sternite.

Etymology.

The species name reflects the state of Mexico from which it is known.