Baconia rufescens, 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 : 149-151

Baconia rufescens sp. n. Figs 42 C–D 43AMap 12

Type locality.

PANAMA: Colón: San Lorenzo Forest [9.28°N, 79.97°W].

Type material.

Holotype male: "PANAMA: Colón Prov., San Lorenzo Forest, STRI crane site. 9°17'N, 79°58'W, FIT B2-18. 26-29 May 2004 A.K.Tishechkin. AT-524" / "Caterino/Tishechkin Exosternini Voucher EXO-00458" (FMNH). Paratypes (2): COSTA RICA:1: Heredia: Est. Biol. La Selva, 3.2 km SE Puerto Viejo, 100 m, 30.i.1992, FIT, W. Bell (SEMC); 1: Est. Biol. La Selva, 10°26'N, 84°01'W, 50-150 m, 1.xi.1993 (INBI).

Other material.

1: ECUADOR: Manabí: Bosque Seco Lalo Loor, 0.0824°S, 80.1503°W, 25.v.2011, fogging understory, M. Caterino & A. Tishechkin, DNA Extract MSC-2168, EXO-00698 (MSCC).

Diagnostic description.

Length: 1.2-1.3mm, width: 0.9-1.0mm; body elongate oval, subdepressed, glabrous; color rufobrunneus, shining; head with frons very shallowly depressed at middle, slightly elevated over antennal bases, ground punctation conspicuous, secondary punctures fine and sparse with few coarser punctures dorsad, frontal and supraorbital striae absent; antennal scape short, club oblong, slightly expanded apically; epistoma truncate apically; labrum about 4 ×wider than long, apical margin straight to slightly emarginate; both mandibles with small, acute basal tooth; pronotum with sides weakly convergent in basal two-thirds, abruptly convergent to apex, lateral marginal stria descending to ventral edge in posterior two-thirds, barely detached anteriorly from anterior marginal stria, free ends of anterior marginal stria may diverge slightly from anterior margin, lateral submarginal stria present in basal three-fourths, pronotal disk weakly depressed in anterolateral corners, ground punctation fine, sparse, with slightly coarser secondary punctures interspersed at sides and along base, disk more or less impuncatate on middle two-thirds; elytra with two epipleural striae, outer subhumeral stria absent, fine fragment of inner subhumeral stria present at base, dorsal striae 1-4 complete to base, vaguely abbreviated apically, 5th and sutural striae slightly abbreviated basally and apically, nearly complete, elytral disk with scattered secondary punctures in apical one-third; prosternum moderately broad, keel very shallowly emarginate at base, carinal striae sinuate, converging slightly anterad; prosternal lobe about two-thirds keel length, apical margin rounded, with marginal stria present only at middle; mesoventrite produced at middle, with marginal stria interrupted for width of prosternal keel; mesometaventral stria arched forward, continuous laterally with inner lateral metaventral stria which curves posterad to middle of metacoxa, outer lateral metaventral stria weak, sinuate behind mesocoxa; metaventral disk moderately coarsely punctate at sides, impunctate at middle; abdominal ventrite 1 with single, complete inner lateral stria, ventrites 2-5 with sparse punctures at sides, finer across middle; protibia weakly tridentate, the outer margin serrulate between denticles; mesotibia with two very weak marginal spines; outer metatibial margin with very fine subbasal denticle; propygidium lacking basal stria, with fine ground punctation and coarser, ocellate secondary punctures uniformly interspersed, propygidial gland openings inconspicuous; pygidium with sparse ground punctation becoming denser apically, with slightly coarser secondary punctation denser toward base. Male genitalia (Fig 42 C–D): T8 narrowly, shallowly emarginate at base, ventrolateral apodemes with inner apices separated by about two-thirds T8 width, projecting beneath just beyond ventral midpoint, obsolete apically, apical margin shallowly emarginate; S8 with halves fused along midline, basal emargination broad, shallow, basal apodemes broadly truncate, sides slightly narrowed, weakly arcuate, apices broadly truncate, setose, narrowly separated by apical emargination; T9 with very short, subacute basal apodemes, halves narrowly separated dorsally, ventrolateral apodemes bluntly produced beneath, nearly meeting, apices narrowly rounded, with single subapical seta on each side; T10 elongate, narrowed basally, with weak apical emargination; S9 with long narrow, medially keeled stem, head abruptly widened, sides parallel to apex, apices acute, widely separated, apical emargination broad, shallow; tegmen with sides weakly widened from base, subparallel to just beyond midpoint, narrowed to apex, apices subacute, tegmen evenly but not strongly curved in lateral aspect; median lobe about one-fourth tegmen length, with subapical denticulate plates; basal piece about one-fourth tegmen length.

Remarks.

Baconia rufescens is distinctive in a number of characters. It exhibits an unusually narrow body form (Fig. 43A), has most of the elytral striae, including the sutural, more or less complete and straight, the 4th stria not arched mediad at the base, and has the mesometaventral stria arched strongly forward, displacing the marginal mesoventral stria. The single specimen from the Pacific slope of Ecuador is very similar in all respects, but is slightly narrower, and has the lateral metaventral striae detached from the mesometaventral stria. Therefore we exclude it from the type series.

Etymology.

This species is named for its rufescent coloration, relatively unusual in this more typically rufopiceous species group.