Baconia cylindrica, 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 : 186-190

Baconia cylindrica sp. n. Figs 52 A–B53A–C, H–IMap 16

Type locality.

FRENCH GUIANA: Rés. des Nouragues [4.0834°N, 52.6833°W].

Type material.

Holotype male:"GUYANE FRANCAISE: Rés. Natur. de Nouragues, Camp Inselberg. 4°05'N, 52°41'W, Piege vitre 8.x.2010. SEAG leg." / "Cateri no Tishechkin Exosternini Voucher EXO-0249" (MNHN); Paratypes (5):2: same data as type, 1: same locality as type, 25.i.2011 (CHND), 1: Rés. des Nouragues, Saut Parare, 4°02'N, 52°41'W, 15.vi.2010, FIT, SEAG, 1:20.iv.2010 (MNHN, CHND, MSCC, FMNH).

Other material.

1: ECUADOR: Orellana, Tiputini Biodiversity Station, 0°37'55"S, 76°08'39"W, 220-250m. 8.ii.1999, T.L.Erwin, fogging of mostly bare green leaves, some with covering of lichenous or bryophytic plants [specimen lost, male genitalia present] (USNM). 1: P.N. Yasuní, Est. Cient. Yasuní, 0°40.5'S, 76°24'W, 28. vi– 5.vii.1999, FIT, C. Carlton & A. Tishechkin (LSAM).

Diagnostic description.

Length: 1.1-1.3mm, width: 0.6-0.7mm; body narrowly elongate, cylindrical, glabrous; color rufescent, shining; head with frons convex, weakly elevated between antennal bases, very weakly depressed along midline, with small, coarse punctures evenly scattered throughout, frontal stria present only along upper edge of eye, absent across front, supraorbital stria present, may be fragmented; antennal scape short, club more or less circular; epistoma faintly emarginate; labrum about 2 ×wider than long, apical margin shallowly emarginate; mandibles short, each with small, acute basal tooth; pronotum with sides subparallel in basal two-thirds, rounded to apex, lateral marginal stria descending to ventral edge of margin behind antennal cavity, faint or merging with lateral submarginal stria, continued around anterior corner but detached from median part of anterior marginal stria, which diverges slightly from margin behind eye; pronotal disk with ground punctation fine, very sparse, with small secondary punctures densest across anterior half; elytra with single, fine epipleural stria, outer subhumeral stria absent, inner subhumeral stria barely impressed at extreme base, dorsal stria 1 present in basal half, striae 2-3 slightly longer, 4th stria pre sent basally and with separate median fragment, 5th and sutural striae present in basal two-thirds, joined in narrow basal arch, elytral disk with small secondary punctures in apical one-fourth; prosternal keel narrow, flat, base produced, with carinal striae converging slightly to front, may be united basally and/or apically; prosternal lobe about two-thirds keel length, apical margin broadly rounded, slightly deflexed, marginal stria obsolete at sides; mesoventrite emarginate at middle, with complete marginal stria; mesometaventral stria absent from middle, inner lateral metaventral stria continuing from marginal mesoventral stria, extending posterad toward inner corner of metacoxa, outer lateral metaventral stria very short, curving behind mesocoxa; metaventral disk sparsely punctate at sides, impunctate at middle; abdominal ventrite 1 with complete inner lateral stria and abbreviated outer stria, central portion of disk impunctate, ventrites 2-5 with fine punctures at sides, sparser across middle; protibiae distinctly tridentate, margin only very finely serrulate between teeth; mesotibia with two marginal and one subapical spines; outer metatibial margin smooth; propygidium lacking basal stria, with fine, sparse ground punctation interspersed with small secondary punctures separated by slightly less than their diameters, propygidial gland openings inconspicuous; pygidium similarly punctate to propygidium, slightly sparser. Male genitalia (Figs 53 A–C, H–I): T8 slightly wider than long, deeply, arcuately emarginate at base, sides weakly converging apicad, ventrolateral apodemes with inner apices opposing, separated by about two-thirds T8 width, projecting beneath to about ventral midpoint, rap idly narrowed apically, apical margin shallowly, narrowly emarginate; S8 with halves fused, basal emargination broad, shallow, sides diverging to apex, apical guides well developed, widest apically, bearing a dense fringe of setae along most of outer margin; T9 with dorsal plates broad to base, proximal apodemes strongly reduced, sides weakly diverging to obliquely truncate apices bearing several conspicuous setae, ventrolateral apodemes strong, nearly meeting at midline about one-third from apex; S9 stem more or less evenly tapered to very narrow base, head bluntly subquadrate, apices divergent, apical emargination narrow; tegmen widest near base, sides undulate, narrowed just distad middle, curved ventrad in apical half, apex rounded; median lobe simple, about one-third tegmen length; basal piece very short, about one-fifth tegmen length.

Remarks.

While this species and the following are easily diagnosed together, they are very similar in their elongate, cylindrical form (Figs 52A, C), and rather difficult to separate from each other. Baconia cylindrica is smaller in body size and has the 4th elytral stria merely interrupted, whereas in Baconia chatzimanolisi , it is largely absent. We exclude specimens from Ecuador from the type series due to slight differences in pronotal and propygidial punctation.

Etymology.

This species is named for its cylindrical body form.