Baconia turgifrons, 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 : 94-96

Baconia turgifrons sp. n. Figs 26 A–B27A–C, G, I–JMap 7

Type locality.

COSTA RICA: Puntarenas: Osa Peninsula [8.68°N, 83.52°W].

Type material.

Holotype male: "COSTA RICA: Punta Prov. Rincon de Osa, 150 m, 8°41.141'N, 83°31.117'W, 23-26-VI-2001, S. & J. Peck, 01-14, ex FIT, CR1P01 006" / "SM0563778 KUNHM-ENT" (SEMC). Paratype (1): Puntarenas: Sector Laguna Meandrica, R.B. Carara, 100 m, vi.1990, R. Zuniga (INBI).

Other material.

FRENCH GUIANA: Mont tabulaire Itoupé, 3°1.82'N, 53°6.40'W, 400m, FIT, 31.iii.2010, SEAG (MNHN).

Diagnostic description.

Length: 1.9-2.1mm, width: 1.7-1.8mm; body elongate oval, convex, glabrous; color piceous, shining; frons very strongly convex, epistoma receding beneath and very finely, densely punctate, frontal disk with only sparse, fine ground punctation, frontal stria interrupted above antennal bases, present at middle (may rarely be complete); supraorbital stria absent; antennal scape short, thick, club oblong, distinctly widened toward apex; labrum reduced, transversely carinate, strongly narrowed to apex, subtriangular; mandibles rather short, convex dorsally, each with small basal tooth; pronotal sides rather evenly narrowed in basal three-fourths, thence abruptly narrowed to apices, lateral marginal striae continuous around sides and front, submarginal stria absent, anterior corners of pronotal disk deflexed, disk with only fine ground punctation at middle, with few coarser secondary punctures near anterolateral corners; elytra with two complete epipleural striae, outer subhumeral stria absent, inner subhumeral stria fragmentarily present at base, dorsal stria 1 scratchlike in apical half, variably abbreviated apically, 2nd stria more or less complete, may be weakly abbreviated basally, 3rd stria present in basal half only, 4th and 5th striae absent, sutural stria present in apical half to two-thirds, elytral disk with few rather coarse punctures in apical fourth; prosternal keel moderately broad, depressed across midline, shallowly emarginate at base, carinal striae convergent between coxae, complete, free; prosternal lobe short, about one-half keel length, apical margin rounded, marginal stria obsolete at sides; mesoventrite weakly produced at middle, marginal stria complete; mesometaventral stria simple, transverse or slightly angulate forward at middle, continued laterally by inner lateral metaventral stria, which is oblique, short, barely reaching middle of metaventrite, outer lateral metaventral stria slightly shorter; metaventral and abdominal disks impunctate at middle; abdominal ventrite 1 with inner lateral striae abbreviated apically, outer lateral stria absent; protibiae 4-dentate, middle pair of spines widely separated, outer margin finely serrulate; meso- and metatibiae rather broad, expanded apically, mesotibia with two marginal spines; outer metatibial margin smooth; propygidium lacking basal stria, with coarse secondary punctures separated by slightly less than their diameters, concentrated in basal two-thirds, propygidial glands inconspicuous; pygidium with fine ground punctation very sparsely interspersed with small secondary punctures, separated by 4 –5× their diameters. Male genitalia (Figs 27 A–C, G, I–J): T8 slightly longer than broad, sides straight, weakly convergent, basal emargination shallow, basal rim well sclerotized, explanate, basal membrane attachment line conspicuous, apex shallowly emarginate, ventrolateral apodemes projecting deeply beneath, to about midpoint of segment, separated by about one-third maximum T8 width, rapidly narrowed apically; S8 divided, inner margins approximate only at base, divergent apically, outer margins weakly rounded, convergent, apical guides widening distally, narrowly rounded at apices, apical velar membrane absent, apex lacking conspicuous setae; T9 with basal apodemes short, only about one-fourth total length, T9 apices narrowed, subacute, glabrous, ventrolateral apodemes prominent beneath; S9 with stem narrowest near midpoint, widened to base and more strongly to apex, apical emargination broadly arcuate, apex broadly desclerotized at middle; tegmen with sides uneven, narrowest just basad midpoint, weakly widened basally and apically, apices bluntly rounded, tegmen in lateral aspect more or less straight; median lobe simple, about one-third tegmen length; basal piece short, about one-fourth tegmen length.

Remarks.

The strongly recessed and microsculptured epistoma (Fig. 26A) and reduced labrum, in combination with the strongly convex frons is unique to this species, as is the pattern of elytral striae, with only the 2nd stria complete, the 1st and 3rd striae abbreviated from the apex, and the 4th and 5th striae absent (Fig. 26B). The following species, Baconia crassa , is very similar, having a microsculptured epistoma, but has the frons depressed in the middle, a complete 1st elytral stria, and a more nearly complete inner metaventral stria.

Etymology.

This species is named for its swollen frons.