Baconia varicolor (Marseul, 1887)

Caterino, Michael S. & Tishechkin, Alexey K., 2013, A systematic revision of Baconia Lewis (Coleoptera, Histeridae, Exosternini), ZooKeys 343, pp. 1-297 : 72-74

Baconia varicolor (Marseul, 1887) Figs 18A19 A–B, G, I, L–M

Phelister varicolor Marseul, 1887b: cxlvii; Baconia varicolor Mazur 1984: 281.

Type locality.

NOUVELLE GRENADE [exact locality uncertain].

Type material.

Lectotype male, here designated (MNHN): "Phelister violaris M violaceus, N.Gren …[illegible]” / "Phelister violaceus ….[illegible]” / “varicolor” / “TYPE” / "LECTOTYPE Phelister varicolor Marseul, 1887, M.S.Caterino & A.K.Tishechkin des. 2010". See discussion under the preceding species for information on this lectotype.

Other material.

2: BRAZIL: Santa Catarina: 14.v.1988 (BMNH), 3: no date (BMNH). 1: COLOMBIA (BMNH). 3: GUATEMALA: S. Geronimo, G. Champion (BMNH).

Diagnostic description.

Length: 2.2-2.5mm, width: 1.9-2.1mm; body elongate oval, weakly depressed, glabrous; dorsum metallic, varied in color from bronzy to greenish-blue to blue or blue-violet; 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, may be complete, but usually fragmented across front, supraorbital stria absent; antennal scape short, club slightly asymmetrically oblong; epistoma slightly convex along apical margin, truncate to weakly emarginate; labrum about 3 ×wider than long, weakly emarginate to bisinuate along apical margin; both mandibles with acute basal tooth; pronotal sides weakly convergent in basal half, 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 toward sides, especially dense, subserially arranged near margin; elytra with two complete epipleural striae, outer subhumeral stria absent, inner subhumeral stria present as basal and rarely median fragments, dorsal striae 1-4 complete, 4th stria arched mediad at base, variably, slightly abbreviated from apex, 5th stria absent, sutural stria present in apical half or more, elytral disk with few coarse punctures in apical fourth; prosternum weakly convex, keel weakly emarginate at base, carinal striae complete, divergent anterad and posterad, separate throughout; prosternal lobe about one-half keel length, weakly deflexed, apical margin rather narrowly rounded, marginal stria obsolete at sides; mes oventrite weakly produced, marginal stria complete, mesometaventral stria subangulately arched forward, narrowly detached at sides; lateral metaventral stria extending from near mesocoxa posterolaterad toward inner third of metacoxa, sinuate apically, outer lateral metaventral stria short, oblique, metaventral disk impunctate at middle; abdominal ventrite 1 with single, complete lateral stria, middle portion of disk impunctate; protibia 4-5 dentate, basal denticles weak, outer margin serrulate between teeth; mesotibia with two weak marginal spines; outer metatibial margin smooth; propygidium without basal stria, discal punctures rather small, ocellate, denser in basal half; propygidial gland openings inconspicuous; pygidium with ground punctation rather dense in apical half, interspersed with small secondary punctures in basal third only. Male genitalia (Figs 19 A–B, G, I, L–M): T8 slightly longer than broad, sides weakly convergent, more or less straight, basal emargination narrowly rounded, apical emargination inconspicuous, ventrolateral apodemes separated by about one-half maximum T8 width, extending beneath to about longitudinal midpoint, narrowed in apical half; S8 halves fused along midline, with broadly expanded, membraneous apical velum, not obviously setose, outer margins subparallel to weakly divergent, apical guides moderately well developed from just beyond base, narrowly rounded apically; T9 with basal apodemes thin, about one-half total length, apices acute, glabrous, ventrolateral apodemes acutely projecting beneath; S9 stem narrowest about two-thirds from base, very weakly expanded to base, strongly desclerotized along midline; tegmen with sides widest near apex, sinuately narrowed toward base, tegmen in lateral aspect weakly curved ventrad in apical fourth; median lobe nearly one-half tegmen length; basal piece about one-third tegmen length.

Remarks.

This species is very hard to characterize. The description above is based on the lectotype (Fig. 18A), but other specimens considered to be this species vary in a number of significant characters. The name alone posits a variable species, but whether this variation is real or if it has been confused with close relatives is very hard to say. Male genitalia of the type are unique, with a broadly apically widened S8, but genitalia are not available for most other purported specimens of the species. So even our own non-type identifications are tentative. The species is most closely related to Baconia eximia and Baconia dives , all of which share a united male 8th sternite.