Baconia insolita (Schmidt, 1893) Schmidt, 1893

Caterino, Michael S. & Tishechkin, Alexey K., 2013, A systematic revision of Baconia Lewis (Coleoptera, Histeridae, Exosternini), ZooKeys 343, pp. 1-297 : 207-209

Baconia insolita (Schmidt, 1893) comb. n. Figs 2D58 A–C 59Map 19

Phelister insolitus Schmidt, 1893a: 12.

Type locality.

MEXICO [exact locality unknown].

Type material.

Lectotype, sex undetermined, here designated (ZMHB): “Mexique” / “Type” / “insolitus” / "insolitus Schm." / "coll. J.Schmidt" / "LECTOTYPE Phelister insolitus Schmidt, 1893, M.S.Caterino & A.K.Tishechkin des. 2010". Paralectotypes (8): same data as type (ZMHB, MNHN, BMNH). This species was described from an unspecified number of specimens, which were evidently distributed widely, and the lectotype designation fixes primary type status on one of the original specimens.

Other material.

MEXICO: 1: Chiapas: P. N. Sumidero, 1000 m, 29.v.1990, FIT, H. & A. Howden (CMNC); 1: Yucatan, 2 km E Chichen Itza, 20 m, 20.vii.1983, S.&J. Peck, seas. forest litter (CMNC) 9: [country record only] (BMNH, FMNH, MHNG).

Diagnostic description.

Length: 1.7-1.8mm, width: 1.2-1.3mm; body elongate, sides subparallel, narrowing slightly to front, weakly depressed, conspicuously punctate on most surfaces, most punctures bearing single short, fine seta (usually abraded on dorsal and ventral surfaces, more persistent on pygidia); color rufopiceous, shining; head with frons produced, elevated over antennal bases, epistoma strongly convex, weakly depressed at middle by high density of punctures, frontal stria broadly interrupted between antennal bases, present along inner edge of eyes, supraorbital stria absent; antennal scape short, subpyramidal, club short, sides rounded, apex subtruncate; epistoma straight across distal margin; labrum about 2.5 × wider than long, rounded at sides, apical margin entire; mandibles strong, rather bulky, each with median tooth; apical maxillary palpomeres slightly widened, markedly setose; pronotum with sides subparallel in basal three-fourths, rather abruptly narrowed to apex, lateral marginal stria continuous around sides and front, lateral submarginal stria absent; pronotal disk weakly depressed in anterior corners, punctation of disk coarse, more or less uniform, just slightly denser toward sides; elytra with inner epipleural stria complete, subhumeral striae absent, dorsal striae 1-3 complete, striae 4-5 varied from nearly complete to highly fragmented, sutural stria more or less complete, elytral disk with sparse secondary punctures throughout, denser in apical fourth; prosternal keel narrow, depressed between coxae, very shallowly emarginate at base, carinal striae convergent at basal third, diverging posterad and anterad, often united at base; prosternal lobe short, less than half keel length, apically shallowly emarginate, marginal stria more or less complete but often slightly fragmented; mesoventrite not produced at middle, marginal stria usually complete, may be fragmented; mesometaventral stria absent from middle, inner lateral metaventral stria extending from inner corner of mesocoxa to middle of metacoxa, outer lateral metaventral stria present or absent, when present paralleling inner stria for brief anterior distance; mesometaventral and abdominal ventral disks with rather sparse secondary punctures throughout; abdominal ventrite 1 with complete inner lateral stria and outer lateral stria in apical half; protibia rather broad, curving, with 6-7 marginal denticles, margin not serrulate between; mesotibia with 3-4 marginal spines, the basal-most spines weak; outer metatibial margin spineless, setose; propygidium lacking basal stria, propygidial gland openings evident about one-third from anterior margin and one-fourth from lateral margins; propygidium and pygidium with coarse punctation throughout. Male genitalia (Fig. 59): T8 strongly reduced, halves separated along midline, inner lobes rounded, ventrolateral apodemes sclerotized, projecting beneath; S8 about as long as broad, halves approximate along inner middle third, sides strongly curved dorsomediad, forming apicolateral rim, apical velar membrane bearing sclerotized median disk; T9 with proximal apodemes narrow, about one-third total length, dorsal lobes evenly narrowed to apices, ventrolateral apodemes very prominent, recurved acutely nearly to base; T10 entire; S9 broader than aedeagus along entire length, base rounded, apex shallowly emarginate; tegmen elongate, narrow, sides sinuate, only very weakly curved ventrad near apex; median lobe simple, about one-fourth tegmen length; basal piece narrower than tegmen, about one-third its length.

Remarks.

This species and the following are unmistakable in their small, punctate, slightly pubescent, parallel-sided form, convex, densely punctate frons (Fig. 58B) and epistoma, weakly emarginate prosternal keel (Fig. 58C), and strongly dentate mandibles. Baconia insolita can be further distinguished by its non-metallic, rufobrunneus coloration. Many typically diagnostic characters are highly varied including striation of the elytra, prosternum, and meso-metaventrites. The male genitalia of Baconia insolita is remarkably autapomorphic, with the divided T8, velar sclerite on the apex of S8, the strongly recurved ventrolateral apodemes of T9, and the wide spiculum gastrale resembling nothing else in the genus. Although the male of Baconia burmeisteri is unknown, its external similarity to Baconia insolita suggests the male’s genitalia would be similar. However, the male genitalia of other species we assign to this group on the basis of seemingly reliable external characters are quite different, so it remains to be seen.