Baconia fornix, 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 : 140-143

Baconia fornix sp. n. Figs 40 C–D41A–B, G, I, K–LMap 12

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. 6 February 1999 T.L.Erwin et al. collectors" / "insecticidal fogging of mostly bare green leaves, some with covering of lichenous or bryophytic plants Lot 2076 Trans. 8 Sta. 7" / "Caterino/Tishechkin Exosternini Voucher EXO-00452" (USNM). Paratypes (1): Res. Ethnica Waorani, 1 km S Onkone Gare Camp, Trans. Ent., 0°39'10"S, 76°26'W, 220 m, 3.vii.1995, fogging, T. Erwin (USNM).

Other material.

1: FRENCH GUIANA:Montagne des Chevaux, 4°43'N, 52°24'W, 4.i.2009, FIT, SEAG (MNHN).

Diagnostic description.

Length: 1.6-1.7mm, width: 1.3-1.4mm; body broadly elongate oval, slightly wider at humeri, weakly convex, glabrous; color rufopiceous, shining, rarely with slight metallic tinge, particularly on elytra; head with frons moderately narrowed and elongate, more or less flat, slightly elevated over antennal bases, ground punctation fine, denser near eyes, secondary punctures slightly coarser, very sparse, frontal stria barely impressed at upper edge of eye, supraorbital stria variably present at middle, may be detached from sides of frontal stria; antennal scape short, club approximately circular; epistoma slightly swollen along apical margin, faintly emarginate apically; labrum about 3 ×wider than long, apical margin shallowly emarginate; mandibles short, each with acute basal tooth; pronotum with sides arcuately convergent in basal two-thirds, curvature markedly interrupted where lateral marginal stria descends to lower edge of margin, about one-fourth from apex, continuous with anterior marginal stria in front, lateral submarginal stria complete, close to marginal, thin marginal bead distinctly elevated, pronotal disk weakly depressed in anterolateral corners, ground punctation fine, very sparse, with slightly coarser secondary punctures interspersed laterally, slightly larger toward prescutellar area, with median impunctate area about head-width; elytra with two epipleural striae, outer subhumeral stria absent, fine fragment of inner subhumeral present at base, often also with detached fragment near middle, dorsal striae 1-4 complete to base, bent mediad in anterior one-third, progressively more abbreviated from apex, base of 4th stria arched mediad to near scutellum, recurved slightly along suture, 5th stria strongly abbreviated from apex, nearly meeting basal arc of 4th, sutural stria more strongly abbreviated, present only in middle one-third, broadened anterad, elytral disk with scattered secondary punctures in apical one-half, densest along apical margin, smaller and sparser anterad; prosternal keel weakly depressed toward front, shallowly emarginate at base, with more or less complete carinal striae converging slightly to front; prosternal lobe about three-fourths keel length, apical margin rounded, with marginal stria present only at middle, and rather dense ground punctation in anterior half; mesoventrite produced at middle, with complete marginal stria; mesometaventral stria arched slightly forward, continuous laterally with inner lateral metaventral stria, extending posterad toward inner corner of metacoxa, curving mediad slightly at apex, outer lateral metaventral stria present in basal half, subparallel to inner; metaventral disk moderately coarsely punctate at sides, impunctate at middle; abdominal ventrite 1 with single, complete inner lateral stria, with secondary punctures rather densely impressed on anterior half of middle portion of disk, ventrites 2-5 with fine punctures at sides, ventrites 2-3 more finely punctate at middle, 4-5 densely punctate across middle; protibia tridentate, the outer margin serrulate between denticles; mesotibia with two marginal spines; outer metatibial margin smooth; propygidium lacking basal stria, with fine ground punc tation and coarser, ocellate secondary punctures uniformly separated by about their diameters, propygidial gland openings inconspicuous; pygidium with sparse ground punctation becoming slightly denser apically, with small secondary punctures denser toward base. Male genitalia (Figs 41 A–B, G, I, K–L): T8 slightly longer than wide, widest just distad middle, basal emargination deep, narrowly arcuate, apical emargination shallow, ventrolateral apodemes with inner apices separated by about two-thirds T8 width, projecting beneath to about ventral midpoint, obsolete apically; S8 with halves fused along midline, basal emargination evenly arcuate, basal apodemes obliquely truncate, sides weakly convergent in basal three-fourths, widening slightly to apices, apices bluntly rounded, bearing 4-5 setae, separated by broad, arcuate apical emargination; T9 with very short, broad basal apodemes, apices narrowly rounded, with single subapical seta on each side, ventrolateral apodemes subacute, projecting nearly to midline beneath; T10 short, undivided; S9 with long narrow stem, head abruptly widened, rather broad, apices acute, widely separated, apical emargination broad, sinuate; tegmen narrow, widest just distad base, very weakly narrowed to apex, apices slightly separated, subacute, tegmen curved ventrad in apical third; median lobe simple, about one-third tegmen length; basal piece about one-fourth tegmen length.

Remarks. This species is very similar and closely related to the preceding, both of them having the apices of the tegmen slightly divergent. Baconia fornix may be distinguished by its slightly broader form (Fig. 40C), rather elongate pronotum and frons, more strongly abbreviated elytral striae 4 and 5, and by the dense punctures on the basal half of abdominal ventrite 1 (Fig. 40D). The singleton from French Guiana exhibits a faint metallic blue coloration shown in neither of the types. It also has the punctures of the 1st abdominal ventrite covering nearly the whole median part of the disk. Therefore we exclude it from the type series.

Etymology. This species’ name refers to the ‘arch’ of the 4th elytral stria.