Baconia subtilis, 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 : 119-122

Baconia subtilis sp. n. Figs 36 A–C, E, I–JMap 9

Type locality.

FRENCH GUIANA: Belvèdére de Saül [3.01°N, 53.21°W].

Type material.

Holotype male: "GUYANE FRANÇAISE: Bélvédère de Saül, point de vue. 3°1'22"N, 53°12'34"W, Piège vitre 2, 7.ii.2011. SEAG leg." / "Caterino/ Tishechkin Exosternini Voucher EXO-01769" (MNHN). Paratype (1): same locality as type, 4.1.2011 (CHND).

Other material.

(1): PERU: Loreto, 45 km W Iquitos, Rio Nanay, Porvenir 3°54'S, 73°33'W. Terra firme, FIT. 19.vi.2011, G.Lamarre. P10 V5 TF (CHND).

Diagnostic description.

Length: 1.7-1.9mm, width: 1.1-1.2mm; body elongate, parallel-sided, weakly depressed, glabrous; color rufescent, shining; frons weakly swollen over antennal bases, slightly depressed at middle, interocular margins convergent dorsad, frontal disk smooth at center, ground punctation moderately conspicuous, few small secondary punctures dorsad, frontal stria absent; antennal scape short, club rounded, slightly wider toward apex; epistoma flat, apex weakly emarginate; labrum about 2.5 × wider than long, apical margin weakly arcuate; mandibles short, each with median tooth; pronotum with sides subparallel in basal two-thirds, arcuate to apex, lateral marginal and submarginal striae merging behind anterior corner, submarginal stria very close to marginal along sides, continued anteriorly around anterior margin, slightly removed from margin above head, crenulate; pronotal disk narrowly depressed along anterolateral margin, ground punctation fine, very sparse, with small, sparse secondary punctures present in lateral thirds separated by 3 × their widths; elytra with two more or less complete epipleural striae, the outer stria may be fragmented, dorsal stria 1 shortened apically, obsolete or fine and scratchlike in apical half, stria 2 nearly complete, striae 3-4 slightly shorter apically, 4th stria arched to meet base of sutural stria, 5th stria absent, sutural stria obsolete in apical third, elytral disk with small, shallow secondary punctures in apical third, fewer towards sides; prosternal keel weakly convex between striae, emarginate at base, carinal striae subparallel basally, diverging slightly anterad; prosternal lobe about two-thirds keel length, deflexed, apical margin rounded, marginal stria obsolete at sides; mesoventrite produced at middle, marginal stria complete; mesometaventral stria transverse, distinctly crenulate, continued by inner lateral metaventral stria posterad toward inner third of metacoxa, outer lateral metaventral stria present as short, oblique postmesocoxal fragment; metaventral disk impunctate at middle; abdominal ventrite 1 with inner lateral stria complete, outer lateral stria absent, disk impunctate at middle, ventrites 2-5 finely punctate across middle; protibia narrow, with three marginal denticles, the distal pair relatively close together, margin serrulate between; mesofemur with posterior marginal stria weakly impressed around distal margin; mesotibia with two marginal spines; outer metatibial margin smooth; propygidium lacking basal stria, ocellate secondary punctures small, sparse, separated by about 1.5 × their diameters, propygidial gland openings inconspicuous; pygidium with fine ground punctation and small, sparse secondary punctures becoming finer but slightly denser toward apex. Male genitalia (Figs 36 A–C, E, I–J): T8 slightly longer than broad, sides more or less parallel, base not emarginate, basal rim moderately well sclerotized, apex narrowly, acutely emarginate, ventrolateral apodemes small, inner apices widely separated beneath; S8 divided, slightly longer than T8, inner margins approximate in basal third, divergent apically, outer margins weakly diverging apically, apical guides closed, apical velar membrane absent, apex with several conspicuous setae; T9 with proximal apodemes thick, wide, nearly one-half total length, dorsal lobe large, broad, weakly narrowed apically, apex rounded, with blunt inner corner, ventrolateral apodeme very weakly developed; S9 cordate, stem absent, base acute, apicolateral corners bearing small ventral digitiform process, apical margin with small median denticle; tegmen widest at base, sides weakly convergent, apex narrowly rounded, tegmen in lateral aspect strongly curved from base to apex; median lobe about one-half tegmen length; basal piece about one-third tegmen length.

Remarks.

Externally there is little to distinguish this species from Baconia guartela (see Figs 32 D–F), with a transverse, crenulate mesometaventral stria, relatively impunctate frons and pronotum, and somewhat longer elytral striae than typical for the group. However, the male 8th sternite has the apices somewhat broadly rounded, with conspicuous apical setae, the 9th tergite has very short, broad basal apodemes and apical lobes, also with several conspicuous apical setae, the spiculum gastrale is subtriangular, with small, ventrally directed, apicolateral processes. The aedeagus shows very pronounced dorsoventral curvature, but not the strong deflection of the basal piece seen in Baconia guartela . The specimen from Peru, a male, shows some slight genitalic differences, and is therefore excluded from the type series.

Etymology.

This species’ name celebrates the subtle differences among species of the Baconia angusta group.