Baconia nebulosa, 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 : 43-46

Baconia nebulosa sp. n. Figs 9 E–F10A–D, I–JMap 2

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, 30 June 1998, T.L.Erwin et al. collectors" / "fogging, bare green leaves, some with covering of lichenous or bryophytic plants in terra firme forest, Lot 1821 Trans. 3 Sta. 2" / "Caterino/Tishechkin Exosternini Voucher EXO-00436" (USNM).

Diagnostic description.

Length: 1.5mm, width: 1.2mm; body broadly subquadrate, moderately strongly depressed, glabrous; head, pronotum and elytra metallic blue, venter and pygidia rufo-brunneus; frons very wide, short, very weakly depressed across middle, interocular margins convergent dorsad, frontal disk with numerous coarser punctures at middle, frontal and supraorbital striae absent; antennal scape short, apex obliquely truncate, club asymmetrically oblong; epistoma truncate apically; labrum very short, about 4 ×wider than long, apex outwardly arcuate; mandibles extremely short, mostly concealed in repose, dentation not observed in type; pronotal sides subparallel in basal third, evenly arcuate to apices, lateral marginal stria complete around lateral and anterior margins, submarginal stria absent, pronotal disk with only fine ground punctation over median third of disk, with small secondary punctures interspersed at sides; elytra with two complete epipleural striae and fragments of a third, outer subhumeral stria absent, inner subhumeral stria present in basal fourth, dorsal striae 1-4 complete, 5th stria present in apical three-fourths, sutural stria absent, elytral disk with scattered secondary punctures in apical fifth; prosternal keel very broad, weakly convex, slightly outwardly produced at base, carinal striae complete, diverging from base to apex; prosternal lobe about one-half keel length, apical margin bluntly rounded, marginal stria present at middle, fragmented to sides; mesoventrite shallowly and broadly emarginate, marginal stria broadly interrupted; mesometaventral stria isolated at middle, arched strongly forward; inner lateral metaventral stria originating close to mesocoxa, extending posterolaterad toward outer corner of metacoxa, abbreviated apically, outer lateral metaventral stria absent; metaventral and 1st abdominal disks impunctate at middle, median metaventral suture rather deeply impressed; abdominal ventrite 1 with complete inner lateral stria and posterior fragment of outer stria; protibia with three weak marginal denticles, outer margin serrulate between spines; mesotibia with single marginal spine; outer metatibial margin smooth; pygidia short and wide, propygidium with complete transverse basal stria, coarse secondary punctures sparse at middle, slightly denser laterad; propygidial gland openings inconspicuous; pygidium with rather dense ground punctation in apical half, small coarse puncture more evident in basal half. Male genitalia (Figs 10 A–D, I–J): T8 about as long as broad, sides weakly convergent to apex, basal emargination evenly arcuate, api cal emargination deep, acute, ventrolateral apodemes well sclerotized, extending just beyond midline beneath, separated by about one-half tegmen width; S8 short, divided, inner edges sinuate, approximate beyond midpoint, outer margins weakly divergent, apical guides widening to rounded apices, without conspicuous setae; T9 with basal apodemes long, thin, about two-thirds total length, T9 apices very narrowly rounded, glabrous, ventrolateral apodemes very poorly developed; T10 entire; S9 widened to rounded base, head abruptly widened, sides subquadrate, sclerotized along lateral margins, not apically divided; tegmen narrowest near base, weakly constricted at middle, apices narrow, subacute, tegmen in lateral aspect rather thick throughout, only very weakly curved dorsoventrally; median lobe simple, about one-fourth tegmen length; basal piece about one-fifth tegmen length.

Remarks.

Among the strongly depressed, metallic species lacking a sutural stria, Baconia nebulosa can be distinguished by its small size, and by its short, wide head and peculiar, mostly concealed mandibles (Fig. 9E).

Etymology.

The name of this species means ‘foggy’, referring mainly to the fact that it was collected by fogging the canopy of lowland forest.