Baconia lunatifrons, 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 : 125-127

Baconia lunatifrons sp. n. Figs 35D37Map 9

Type locality.

SURINAME: Para: 11km SE Zanderij Airport [5.39°N, 55.27°W].

Type material.

Holotype male: "SURINAM: Para, 11km SE Zanderij Airport, 30m, FIT, 20.VI.1999,Z.Falin" / "Caterino/Tishechkin Exosternini Voucher EXO-00473" (CMNC).

Diagnostic description.

Length: 1.8mm, width: 1.1mm; body elongate, parallel-sided, weakly depressed, glabrous; color rufescent, shining; head with frons rather broad, weakly elevated over antennal bases, more or less flat across middle, interocular margins convergent dorsad, frontal punctures small, uniform, rather dense above antennal bases, frontal stria absent; antennal scape short, club rounded; epistoma flat, apex truncate; labrum short, flat, about 4 × wider than long, apical margin weakly emarginate; mandibles short, each with median tooth; pronotum with sides subparallel in basal half, rounded to apex, lateral marginal and submarginal striae very nearly merging near anterior corner, submarginal stria close to marginal at sides, continued anteriorly around anterior margin, slightly removed from margin anteriorly, coarsely crenulate above head; pronotal disk narrowly depressed along anterolateral margin, ground punctation fine, very sparse, with small secondary punctures sparsely scattered in lateral thirds; elytra with two epipleural striae, the outermost may be fragmented or abbreviated, outer and inner subhumeral striae absent, dorsal stria 1 nearly complete, fine, scratchlike in apical fourth, stria 2 nearly complete, striae 3-4 progressively more abbreviated apically, 4th stria arched to meet base of sutural stria, 5th stria absent, sutural stria obsolete in apical fourth, elytral disk with small, shallow secondary punctures in apical third; prosternal keel narrow, weakly convex between striae, slightly pinched at middle, narrowly emarginate at base, carinal striae convergent to middle; prosternal lobe about two-thirds keel length, apex weakly deflexed, apical margin broadly rounded, marginal stria obsolete at sides; mesoventrite subacutely produced at middle, marginal stria complete; mesometaventral stria weakly arched forward, distinctly cren ulate, barely detached from inner lateral metaventral stria, which continues posterad toward inner third of metacoxa, outer lateral metaventral stria short, present as an oblique postmesocoxal fragment; metaventral disk impunctate at middle; abdominal ventrite 1 with inner lateral stria complete, outer lateral stria short, present only behind coxa, disk impunctate at middle, ventrites 2-5 finely punctate across middle; protibia narrow, with four weak marginal denticles, the middle pair more widely separated, margin serrulate between; mesofemur narrowing apically, posterior marginal stria following margin, weakly impressed along distal margin; mesotibia with two distinct marginal spines; outer metatibial margin smooth; propygidium lacking basal stria, with ocellate secondary punctures separated by slightly more than their diameters, smaller and denser anteriorly, propygidial gland openings inconspicuous; pygidium with fine ground punctation and very small, sparse secondary punctures throughout. Male genitalia (Fig. 37): T8 broad, short, sides weakly convergent to apex, basal emargination very shallow, basal rim moderately well sclerotized, apex narrowly, acutely emarginate, ventrolateral apodemes small, inner apices separated by three-fourths T8 width; S8 divided, slightly longer than T8, inner margins approximate in basal third, divergent apically, outer margins diverging apically, apical guides closed, apical velar membrane absent, apex with several conspicuous setae; T9 with proximal apodemes short, rather broad, about one-third total length, dorsal lobe large, subquadrate, only weakly narrowed to broad, truncate apex, ventrolateral apodeme bluntly dentate beneath; S9 wide, shallow, stem absent, basal edge acuminate, distal arms divergent, with apices bent abruptly inward, inner margin with acute median tooth; tegmen moderately broad, sides rounded, widest basad middle, narrowed distally, apices narrowly rounded, tegmen in lateral aspect rather strongly curved ventrad, distinctly and abruptly flatter in apical fourth; median lobe about two-thirds tegmen length; basal piece about one-third tegmen length.

Remarks.

There are few external characters to distinguish Baconia lunatifrons from either Baconia guartela or Baconia subtilis , although the broad, evenly and finely punctate frons (Fig. 35D) is weakly distinctive. Like Baconia subtilis , the male 9th tergite has short, broad proximal apodemes, and broadly subtruncate apices. However, its spiculum gastrale is much more like that of Baconia cavei , being deeply emarginate apically, with a strong median projection. The aedeagus is strongly curved dorsoventrally, and the apical third is distinctly compressed dorsoventrally.

Etymology.

This species’ name refers to its large, semicircular frons, lacking marginal striae.