Baconia venusta (J.E. LeConte, 1845)

Caterino, Michael S. & Tishechkin, Alexey K., 2013, A systematic revision of Baconia Lewis (Coleoptera, Histeridae, Exosternini), ZooKeys 343, pp. 1-297 : 52-55

Baconia venusta (J.E. LeConte, 1845) Figs 11 C–F12E–H, K–LMap 4

Platysoma venustum Dejean, 1837 (nom. nud.)

Platysoma venustum J.E. LeConte, 1845: 86; Hister venustus : J.L. LeConte 1851: 163; Phelister venustus : Marseul 1853: 468; Phelister venustulus Marseul 1862: 706 (emend.); Baconia venusta : Mazur 1984: 281.

Phelister venustus chalybaeus Casey, 1916: 234; Baconia venusta chalybaea : Mazur 1984: 281 (as valid subsp.); Wenzel in Mazur 1997: 26 (synonymized).

Type locality.

UNITED STATES: 'Southern states’ [exact locality uncertain].

Type material.

Lectotype, here designated (MCZC): [orange locality disk indicating collection in 'southern states’ (Carolina and Georgia as per original description)] / “7126” / "Type 6896" / "H. venustus Lec." / "LECTOTYPE Platysoma venustum J.E.LeConte, M.S.Caterino & A.K.Tishechkin des. 2010". This species was described from an unspecified number of specimens, and the lectotype designation fixes primary type status on the only known specimen.

Other material.

USA: Alabama: 2: Baldwin Co., Daphne, 8.viii.1958, under bark gum tree, B.K. Dozier (FSCA); 1: Colbert Co., 3mi. W Tuscumbia, 21.vi.1959, under bark, H. Steeves (FMNH); 1: Jefferson Co., Birmingham, Rocky Ridge, 14.vi.1983, at light, W. Suter (FMNH); 1: Mobile Co., Mobile, 16.xi.1924, H. Loding (FMNH), 2: no date (SEMC, FMNH); Arkansas: 2: southwest Arkansas (AMNH); 2: Arkansas, state record only (FMNH, AMNH); Florida: 1: Alachua Co., Newnan’s Lake, 14.vi.1965, C.W. O’Brien (MHNG); 1: Levy Do., 4 mi SW Archer, 4.vi.1994, at light, R. Aalbu (CDFA); 1: Santa Rosa Co., Milton, Lindgren trap baited with Persea borbonia , 21.vi.2007, R. Robinson(FSCA); 1: Marion Co., Ocala, 17.viii.1977, M.C. Thomas (FSCA); 1: Dixie Co. 6 mi N Old Town, 23.vii.1978, M.C. Thomas (FSCA); 1: Putnam Co., 2.iii.1960, under bark dead Quercus laevis , H.V. Weems (FSCA), 1: same data but 18.vi.1960 (FSCA); 1: A. Slosson (AMNH); Kansas: 1: Woodson Co., Cross Timbers St. Pk., E Spillway Access, 37.73918°N, 95.91898°W, 10.vi.2010, under bark, Z. Falin, DNA Extract MSC-2231, EXO-00944; 1: Louisiana: 1: East Baton Rouge Par., Baton Rouge, 12.ii.1982, under bark, S.M. Strother (LSAM); 1: Natchitoches Par., 1 mi NNE Lotus, 31°30'N, 93°7.5'W, 12.iv-3.vii.1996, FIT, A. Cline, S. Dash & M. Seymour (LSAM); 1: W Feliciana Par., Feliciana Pres., nr. Free land, 30°47'N, 91°15'W, FIT, 29. v– 12.vi.2005, A. Tishechkin & S. Gil (LSAM); Maryland: 4: Pr. Georges Co., 18.vii.1948, under bark (thin) tree, fire-killed 3 1/2 mos prior, G. Vogt (USNM), 5: 19.vi.1949, tree, fire-killed 14 1/2 mos. ago, red or black oak, G. Vogt (USNM), 1: 3.vii.1948, under thin bark red or black oak, fire-killed 3 mos. prior, G. Vogt (USNM); Mississippi: 4: George Co., Lucedale, 16.i.1931, H. Dietrich (FMNH), 1: 18.iv.1930, H. Dietrich (FMNH); North Carolina: 1: Guilford Co., Greensboro, 21.vi.1956, P. Ashlock (SEMC); 1: Southern Pines, 24.xi.1911, A.H. Manee (FMNH), 3: 25.iii.1911, 1: 25.ii.1911, 1: 16.i.1911, 1: 8.i.1915 (NCSU); 1: Cleveland Co., 20.v.1972, J. Ashe; Oklahoma: 2: Latimer Co., 5 mi. W Red Oak, x.1980, K. Stephan, 1: vi.1981, 5: vi.1982, 1: xi.1982, 3: v.1983, FIT, 1: vi.1983, 1: vi.1984, FIT, 1: v.1984, FIT, 1: v.1984, tree hole oak + rodent, 1: iv.1985, 2: vi.1985, 1: vii.1985, 1: v.1986, 3: v.1987, 2: iv.1991, 2: v.1991, 1: v.1993, 1: vi.1993, 1: iv.1994, 1: vii.1995 (all K. Stephan; FMNH, TAMU, FSCA); Tennessee: Hardeman Co., 5 mi S Bolivar on Union RD(8232), 200m, 28.vii.1972 (MHNG); 1: Texas: Brazos Co., 9.xi.1935, J. Robinson (FMNH).

Diagnostic description.

Length: 2.0-2.3mm, width: 1.7-2.0mm; body elongate oval, depressed, glabrous; dorsum metallic blue to greenish-blue, venter rufopiceous; frons elevated over antennal bases, depressed at middle, ground punctation fine, with few coarse punctures at middle and near vertex, frontal stria present along inner margin of eye, curving inward at front, interrupted over antennal bases, at middle, or both, supraorbital stria vaguely represented by series of punctures; antennal scape short, club broadly rounded; epistoma truncate apically; labrum about 4 ×wider than long, weakly bisinuate along apical margin; both mandibles with acute basal tooth; pronotum with sides increasingly arcuate to apex, marginal stria complete along lateral and anterior margins, lateral submarginal stria absent, ground punctation of pronotal disk rather conspicuous, interspersed with coarser secondary punctures at sides, nearly to midline anteriorly; elytra with two complete epipleural striae, outer subhumeral stria absent, inner subhumeral stria present as basal and frequently median fragments, dorsal striae 1-4 complete, 5th stria present in apical two-thirds and frequently with basal puncture, sutural stria present in apical half or slightly more, elytral disk with few coarse punctures in apical fourth; prosternum moderately broad, weakly convex, keel emarginate at base, carinal striae complete, subparallel to divergent anterad, separate or united along basal margin; prosternal lobe about two-thirds keel length, apical margin rounded, marginal stria obsolete at sides; mesoventrite produced at middle, marginal stria narrowly interrupted at middle; mesometaventral stria arched forward, crenulate, narrowly detached from lateral metaventral stria, which curves posterolaterad toward middle of metacoxa, outer lateral metaventral stria absent, metaventral disk impunctate at middle; abdominal ventrite 1 with single, complete lateral stria, middle portion of disk lacking coarse punctures; protibia 4-5 dentate, the basal one or two denticles weak, outer margin serrulate between teeth; mesotibia with two weak marginal spines; outer metatibial margin smooth; propygidium with complete transverse basal stria, discal punctures ocellate, separated more or less uniformly by about their diameters; propygidial gland openings evident behind ends of transverse basal stria, about one-fourth from each lateral margin; pygidium with ground punctation rather dense in apical half, secondary punctation denser toward base. Male genitalia (Figs 12 E–H, K–L): T8 about as long as broad, sides subparallel, narrowed to base, basal emargination broadly, unevenly rounded, apical emargination very shallow, ventrolateral apodemes separated by about one-half maximum T8 width, extending about one-third distad beneath, strongly narrowed in apical half; S8 longer than T8, divided, inner margins approximate along basal one-fourth, strongly divergent apically, bearing conspicuous fringe of setae along apical one-third, outer margins subparallel to weakly divergent, apical guides well developed in apical half, broadly rounded apically; T9 with basal apodemes thin, about one-half total length, T9 apices narrowly rounded, glabrous, ventrolateral apodemes moderately strongly projecting beneath; S9 widened in basal half, head similar in width, subangulate to apicolateral points, desclerotized along midline, with narrow apicomedial division; tegmen with sides subparallel in basal half, weakly widened to apex, dorsobasal edge projecting, tegmen in lateral aspect more or less straight, slightly curved ventrad at apex; median lobe about one-fourth tegmen length; basal piece about one-fifth tegmen length.

Remarks.

This is one of only three species of Baconia occurring in the eastern US, and only shares metallic coloration with one, Baconia aeneomicans . It is easily distinguished from this species (see Fig. 38A) by its larger size, more broadly rounded body form, and relatively uniform coloration (Fig. 11C).One additional species occurs in the American southwest, Baconia navarretei , which is more similar. It is not likely that the ranges of these species will overlap, but Baconia venusta is nonetheless easily distinguished by the presence of a basal propygidial stria, and the presence of the median portion of the mesometaventral stria (Fig. 11D), both striae lacking in Baconia navarretei .

Mazur (2011) reported this species from Mexico. However, we have studied those specimens and assign them to Baconia eximia , below.