Baconia castanea, 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 : 162-164

Baconia castanea sp. n. Figs 45DE46 A–D, I–JMap 13

Type locality.

Type locality. FRENCH GUIANA: Montagne des Chevaux [4.72°N, 52.40°W].

Type material.

Holotype male: "GUYANE FRANÇAISE:Montagne des Chevaux 4°43'N, 52°24'W, Piège d’interception 31 Mai 2009. SEAG leg." / "Caterino/Tishechkin Exosternini Voucher EXO-00461" (MNHN). Paratypes (31): FRENCH GUIANA: 2: Rés. des Nouragues, Camp Inselberg, 4°05'N, 52°41'W, 25.i.2011, FIT, SEAG; 4: Rés. des Nouragues, Camp Inselberg, 4°05'N, 52°41'W, 8.x.2010, FIT, SEAG, 3:9.ix.2010, FIT, SEAG; 1: Rés. des Nouragues, Régina, 4°2.27'N, 52°40.35'W, 10.x.2009, FIT, SEAG (CHND); 1:Res. Tresor, rte. de Kaw, Pk18, 4°36.63'N, 52°16.74'W, 225 m, 13.x.2009, FIT, SEAG (CHND); 1: Belvèdére de Saül, 3°1'22"N, 53°12'34"W, 31.xi.2010, FIT, SEAG, 4:17.i.2011, FIT, SEAG, 2:20.xii.2010, FIT, SEAG, 1:4.i.2011, FIT, SEAG, 4:7.ii.2011, FIT, SEAG, 1:Montagne des Chevaux, 4°43'N, 52°24'W, 13.vi.2009, FIT, SEAG (CHND), 1:27.vi.2009, FIT, SEAG (CHND). 1: GUYANA: Region 8:Iwokrama Field Stn., Pakatau hills, 4°44'54"N, 59°1'36"W, 70 m, 25-29.v.2001, FIT, R. Brooks & Z. Falin (SEMC); 1: Kabocalli Field Stn., 4°17'4"N, 58°30'35"W, 60 m, 3-5.vi.2001, FIT, R. Brooks & Z. Falin (SEMC); 1:Kurupukari, 4°40'N, 58°40'W, ix-xi.1992, Malaise/FIT (BMNH). 1: SURINAME: Pará: nr. Overbridge River Resort, 5°31.8'N, 55°3.5'W, 15-18.ii.2010, FIT, C. Gillet, P. Skelley, W. Warner (FSCA).1: BRAZIL: Mato Grosso:Mpio. Cotriguaçu, Fazenda São Nicolau, Matinha, 9°50.3'S, 58°15.05'W, x.2009, FIT, F. Vaz-de-Mello (CEMT).

Diagnostic description.

Length: 1.2-1.5mm, width: 1.0-1.2mm; body broadly elongate oval, subparallel-sided, subdepressed, glabrous; color rufobrunneus, shining; head with frons more or less flat, ground punctation conspicuous, slightly denser at front and sides, with sparse coarser punctures dorsad, frontal stria absent or present only at up per corner of eye, absent across front, supraorbital stria usually absent, median fragments may be present; antennal scape short, club slightly oblong; epistoma faintly emarginate; labrum about 4 ×wider than long, apical margin shallowly emarginate; mandibles short, each with acute basal tooth; pronotum with sides weakly convergent in basal two-thirds, rounded to apex, lateral marginal stria descending to ventral edge of pronotum in posterior two-thirds, detached from or merging with lateral submarginal stria, which extends around anterior corners, anterior marginal stria usually detached from lateral marginal, may diverge from anterior margin behind eye, pronotal disk very weakly depressed in anterolateral corners, ground punctation fine, very sparse, coarser secondary punctures sparsely scattered in lateral thirds and further mediad along basal margin; elytra with two epipleural striae, outer subhumeral stria absent, inner subhumeral stria present in basal two-thirds, dorsal striae 1-2 similar in length, only slightly abbreviated apically, 3 rd and 4th striae present in about basal two-thirds, 4th stria curving slightly mediad at base, 5th stria shorter than 4th, more strongly abbreviated basally, sutural stria similar in length to 5th, displaced slightly posterad, elytral disk with small, sparse secondary punctures in nearly apical half, extending slightly further anterad toward middle; prosternal keel weakly convex, shallowly emarginate at base, with more or less complete, carinal striae subparallel; prosternal lobe about two-thirds keel length, apical margin rounded, marginal stria fragmented to sides; mesoventrite produced at middle, with marginal stria interrupted for nearly width of prosternal keel; mesometaventral stria arched forward at middle, continuous laterally with inner lateral metaventral stria, extending posterad toward middle of metacoxa, outer lateral metaventral stria very short, oblique; metaventral disk moderately coarsely punctate at sides, impunctate at middle; abdominal ventrite 1 with single, complete inner lateral stria, lacking median discal punctures, ventrites 2-5 with fine punctures at sides, those of ventrite 4 dense across middle; protibiae bidentate, with median marginal teeth generally absent, margin serrulate; mesotibia usually with only one marginal spine; outer metatibial margin with fine denticle near midpoint; propygidium lacking basal stria, with fine ground punctation and rather dense, ocellate secondary punctures, propygidial gland openings visible about one-fourth from basal and lateral margins; pygidium with sparse ground punctation becoming slightly denser apically, with small secondary punctures conspicuous throughout. Male genitalia (Figs 46 A–D, I–J): T8 broadly, shallowly emarginate at base, ventrolateral apodemes with inner apices separated by about three-fourths T8 width, projecting beneath about two-thirds its length, obsolete apically, apical margin shallowly, acutely emarginate; S8 very short, with halves fused along midline, basal emargination broad, evenly arcuate, basal apodemes widely separated, obliquely truncate, sides slightly narrowed to midline, then widened to apex, apices each with subcarinate upper edge, weakly trilobed lower edge, each lobe bearing a seta, apices separated by apical emargination about one-fourth total width; T9 with short, subacute basal apodemes, halves narrowly separated dorsally, ventrolateral apodemes subacutely produced beneath, nearly meeting, sides narrowed to near apex, but apices turned outward, outer edges rather distinctly sclerotized, with apical seta on each side; T10 short, 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 narrowed from base, apices subacute, tegmen evenly weakly curved in lateral aspect, with eversible subapical denticles ventrally; median lobe about one-fourth tegmen length; basal piece about one-third tegmen length.

Remarks.

The most distinctive character of Baconia castanea is its bidentate protibia (Fig. 45D), with the median marginal tooth strongly reduced to absent. In addition, its long inner subhumeral stria, approximately two-thirds the elytral length, is unusual in the Baconia aeneomicans group. The male genitalia are quite distinct, with the apical lobes of the 8th sternite being strongly tridentate beneath an apicodorsal ridge, and the apices of the 9th tergite bent laterad, with the typically sub-apical seta displaced to the apex.

Etymology.

The name of this species refers to its castaneus coloration, in contrast to the metallic coloration of many species of the genus.