Baconia ruficauda, 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 : 105-107

Baconia ruficauda sp. n. Figs 30A31 A–CMap 8

Type locality.

ECUADOR: Orellana: Tiputini Biodiversity Station [0.635°S, 76.150°W].

Type material. Holotype male: "ECUADOR: Depto. Orellana, Tiputini Biodiversity Station 0°37'55"S, 76°08'39"W, 220-250m. 2 October 1996 T.L.Erwin et al. collectors" / "insecticidal fogging of mostly bare green leaves, some with covering of lichenous or bryophytic plants Lot 1718 Trans. 6 Sta. 8" / "Caterino/Tishechkin Exosternini Voucher EXO-00469" (USNM). Paratypes (3):same locality and data as type except as noted: 1: 21.vi.1996 (USNM), 1: 23.i.2006 (USNM), 1: 9.vii.2006, DNA Extract MSC-2135, EXO-00666 (MSCC).

Other material.

1: FRENCH GUIANA: Belvèdére de Saül, 3°1'22"N, 53°12'34"W, FIT, 17.i.2011, SEAG (CHND).

Diagnostic description.

Length: 1.5-1.6mm, width: 1.0-1.1mm; body elongate, parallel-sided, weakly depressed, glabrous; head and pronotum metallic greenish-blue, very slightly contrasting with blue elytra, apical margin of elytra, pygidia, and venter rufescent; frons broad, together with epistoma strongly convex, interocular margins strongly convergent dorsad, few coarse punctures present throughout, especially at middle and toward vertex, frontal and supraorbital striae absent; antennal scape short, club rounded; epistoma weakly emarginate apically; labrum about 3 ×wider than long, apex weakly emarginate; mandibles short, left mandible with small acute tooth, right mandible only bluntly produced at base; pronotal sides subparallel in basal two-thirds, arcuate to apex, marginal stria complete around lateral and anterior margins, slightly removed from anterior margin, submarginal stria absent; pronotal disk with fine ground punctation conspicuous throughout, with small secondary punctures interspersed in lateral thirds; elytra with two complete epipleural striae, outer subhumeral stria absent, inner subhumeral stria faintly impressed at base, dorsal striae 1-3 complete, 4th stria usually interrupted to obsolete in apical half, 5th stria present in basal two-thirds, sutural stria nearly complete, weakly abbreviated basally and apically, elytral disk with very sparse secondary punctures in apical third; prosternal keel narrow, convex, base truncate, carinal striae complete to fragmented basally and apically; prosternal lobe about two-thirds keel length, deflexed, apically rounded, marginal stria slightly fragmented at sides; mesoventrite subacutely produced at middle (inconsistent with trun cate prosternal keel), marginal stria narrowly interrupted at middle; mesometaventral stria narrowly arched forward, crenulate, meeting inner lateral metaventral stria close to mesocoxa, weakly curving obliquely posterolaterad toward outer third of metacoxa, outer lateral metaventral stria absent, metaventral and 1st abdominal disks impunctate at middle; abdominal ventrite 1 with complete inner lateral stria and posterior fragments of outer stria; protibia with four marginal denticles, the basalmost weak, outer margin serrulate between; mesotibia with two distinct marginal spines; outer metatibial margin smooth; propygidium without transverse basal stria, with moderately large, ocellate punctures sparsely scattered at middle, smaller and denser toward anterior margin; propygidial gland openings inconspicuous; pygidium with fine, sparse ground punctation throughout, with small, sparse secondary punctures more conspicuous in basal half. Male genitalia (Figs 31A-C): T8, S8, S9 weakly sclerotized and poorly preserved, few details discernable: basal rim slightly sclerotized, basal emargination shallow, subangulate, ventrolateral apodemes extending beneath about one-half T8 length; T 9 with basal apodemes long, thin, almost two-thirds total length, T9 apices narrow, acute, lacking setae, ventrolateral apodemes weak; T10 small, entire; tegmen widest one-fourth from base, weakly and unevenly narrowed to apex, tegmen in lateral aspect rather thick throughout, evenly curved in apical two-thirds; median lobe simple, about one-third tegmen length; basal piece short, about one-fifth tegmen length.

Remarks.

Within this group, this species is by far the smaller of the two. Its distinctive color pattern (Fig. 21A) is largely sufficient to distinguish it, with the metallic blue elytra becoming apically rufescent to match the pygidia and venter. In addition, the 4th elytral stria is significantly abbreviated from the apex in most individuals. It is superficially similar to Baconia tricolor , in the Baconia insolitus group, in body shape and coloration. But the two differ greatly in genitalic characters, and Baconia ruficauda is not externally setose.

Etymology.

This species is named for its rufescent posterior end.