Tomogenius incisus (Erichson, 1842)

Lackner, Tomas & Leschen, Richard A. B., 2017, A monograph of the Australopacific Saprininae (Coleoptera, Histeridae), ZooKeys 689, pp. 1-263 : 181-187

Tomogenius incisus (Erichson, 1842) Figs 638, 639-647, 648-650, 651-659, 767

Saprinus incisus Erichson, 1842: 152.

Saprinus incisisternus Marseul, 1862: 497, plate 12, fig. 1 (emend.).

Type locality.

Australia: Tasmania.

Type material examined.

Saprinus incisus Erichson, 1842: Lectotype, present designation: ♂, right mid-leg missing, pinned, with genitalia extracted, glued to the mounting card under specimen; card with genitalia bears pencil-written inscription on its underside: "INCISUS / TYPE" apparently written there by Dahlgren; followed by: "Terra v Diemen / Schayer / Nr. 49180" (beige, written label); followed by: “Type” (brick-red label, printed); followed by: "Hist. Coll. Coleoptera / Nr. 49180 / Saprinus incisus Er. x / Terra v. Diemen, Schayer / Zool. Mus. Berlin" (violet, black margined label, printed); followed by: " Saprinus incisus / Erichson, 1842 / LECTOTYPE / des. T. Lackner 2014" (red label, written) (ZMHUB). Paralectotype, present designation, ♀, both metatarsi missing, with printed label: “49180”; followed by: " incisus Er. / Van Diem. Schayer" (dark-beige label, written); followed by the two labels of the lectotype, with additional paralectotype label (ZMHUB). This species was described from unknown number of specimens and the lectotype designation fixes the identity of the species.

Saprinus incisisternus Marseul, 1862: 497: Lectotype, present designation: ♂ pinned, both protarsi, left mesotarsus and left hind leg missing, with tiny rectangular dark blue label, followed by the following labels: "119a Saprinus / incisus Er. / v Diemen / illegible" (written); followed by: " Gnathoncus / incisisternus m. / incisus Er./ V. Diemen / T. Er. Band 60??" (round pink label, written); followed by: "MUSEUM PARIS / COLL. / DE MARSEUL 1890" (pink label, printed); followed by: " Saprinus / incisisternus / Marseul, 1862 / LECTOTYPE 2014 / des. T. Lackner" (red label, written) (MNHN). This species was described from an unknown number of specimens and we therefore designate a lectotype to formally fix its taxonomic identity.

Additional material examined.

AUSTRALIA. Queensland: 1 spec., Cape York, without further data (BMNH); 1 spec., Tallebudgera valley falls area, 150 m, 28°14'S, 153°19'E, 22.iv.2001, D.J. Cook leg. (NCB); 2 specs., ditto (QM); 2 specs., ditto, but 18.vi.2000 (QM); 7 specs., ditto, but 28.i.-21.v.1998, pitfall in bat guano (QM); 10 specs., ditto, but 21.v.-26.ix.1998 (QM); 4 spec, ditto, but 11.xi.1997-28.i.1998 (QM); 7 specs., Keniff Cave, Mt. Mofatt NP, 25°09'S, 148°01'E, 26.ix.1995, G.B. Monteith (QM); 4 specs., Finchhatton, Doolemai Cave, 22.v.1982, M. Crowther leg. (QM); 1 spec., 3 km W of Bangalee Beach, 23°04'S, 150°44'E, open forest, fungus pit, 20 m, D. Cook leg. (QM); 1 spec., Mt. Etna, Johannsens mine, 15.v.1986, ex ghost bat guano, E. Holm leg. (ANIC). New South Wales: 1 spec., Wee Jasper, Church Cave, 27.viii.1985, ex bat droppings; 2 specs., Deua National Park, Deua Cave, 5.iv.1986, ex bat guano (ANIC); 9 ♂♂ & 8 ♀♀, 20 km W of Kempsey, Yessabah Cave, 14.i.1987, E. Holm leg., bat guano (ANIC); 2 ♀♀, Glass Cave, Wombeyan, 21.ii.1965, I.D. Wood (ANIC). Australian Capital Territory: 1 ♂, N Canberra, 7.iii.1970, K.R. Pullen leg. (ANIC). Victoria: 1 ♂ & 3 ♀♀, Novgun’s Cave, 3.xi.1964, K.G. Simpson leg., guano (ANIC); 1 ♀, Guano Cave, Lake Gilleur (?), 8.xii.1962, R.J. Edge (ANIC). South Australia: 1 ♂ & 1 ♀, Naracoorte, 36°58'S, 140°45'E, 8.xi.1987, A. Spate leg., ex bat guano (ANIC).

Biology.

Found mostly in caves and in bat guano where it presumably preys on larvae of small arthropods.

Distribution.

Australia: Victoria, South Australia, Australian Capital Territory, New South Wales, Tasmania, and Queensland (Fig. 767).

Remarks.

This is a sexually dimorphic species, with males having setose prosternites and meso- and metaventrites. The species is widely distributed and variable in size, color and punctation across Australia.

Re-description.

Body length: PEL: 2.15-3.50 mm; APW: 0.85-1.25 mm; PPW: 1.50-2.50 mm; EL: 1.40-2.25 mm; EW: 1.65-2.75 mm.

Body (Fig. 638) ovoid, moderately convex from above, underside slightly flattened, cuticle castaneous to dark brown, almost black without metallic luster; legs and body appendages similarly colored.

Antennal scape (Fig. 639) not particularly thickened, with few short setae; club (Fig. 640) rather large, oval, ventrally with two slit-like pits, entirely covered in dense short sensilla, intermingled with sparse longer erect sensilla; sensory structures of antennal club (Fig. 650) in form of two dorsal oval sensory areas and two ventral slit like pits and large single ball-like vesicle situated in middle of club.

Mandibles (Fig. 648) with rounded outer margin, acutely pointed, sub-apical tooth on inner margin of left mandible very small, almost inconspicuous; labrum (Fig. 649) slightly convex dorsally, sparsely punctate, approximately three times as wide as long, with small median projection; labral fold significantly small; setae of lateral fringe short; labrum with two moderately long labral setae; terminal labial palpomere elongated, its width about one-fourth its length; palpal organ present on both labial and maxillary palpi; mentum sub-trapezoid, anterior angles slightly produced, anterior margin with a shallow median notch, surface around it with single long seta, lateral margins with a single one row of much shorter sparse ramose setae, disc with few scattered setae; cardo of maxilla with few short setae on lateral margin; stipes triangular, with three short setae; lacinia with lacinial hook; terminal maxillary palpomere elongated, its width about one-fourth its length, about three times as long as penultimate palpomere.

Clypeus (Fig. 639) large, rectangular, rounded laterally, with sparse fine punctures, separated by several times their diameter; frontal and supraorbital striae absent; frontal disc (Fig. 639) with sparse fine round punctures; eyes convex, well visible from above.

Pronotal sides (Fig. 638) feebly convergent anteriorly, apical angles produced, marginal pronotal stria complete, thin, slightly carinate, somewhat weakened behind head; disc entirely with deep, round punctation, becoming coarser and denser laterally, medially punctures separated by several times their diameter; pronotal hypomeron glabrous; scutellum very small.

Elytral epipleura with scattered punctures of various sizes; marginal epipleural stria double, both striae weakly impressed but complete; marginal elytral stria well impressed, continuous along elytral apex as apical elytral stria, stopping in middle of elytral apical margin; humeral elytral stria well impressed on basal third, surface around it striolate; inner subhumeral stria present medially, short; elytral disc with four dorsal elytral striae 1-4, first the longest, reaching about two-thirds of elytral length apically, occasionally longer, second to fourth striae well impressed, only slightly shorter than first; between fourth dorsal elytral and sutural striae a characteristic hooked appendix present; sutural elytral stria almost complete, usually reaching as far as 5/6 of elytral length apically. Entire elytral disc punctate, on basal half (roughly) punctures finer and sparser separated by about their own to twice to three times their diameter (occasionally space between base of fourth dorsal elytral and sutural striae almost smooth), on apical half (roughly) punctures larger and denser, separated approximately by their diameter; punctures near extreme elytral apex with minuscule striolae among them.

Propygidium (Fig. 641) transverse, about four times as broad as long, completely exposed, with dense and coarse punctures separated by less than their diameter, intermingled with tiny scattered punctures; pygidium (Fig. 641) with similar round punctures, separated by about their diameter, becoming sparser and finer towards apex.

Anterior margin of median portion of prosternum (Fig. 642) rounded; marginal prosternal stria present only laterally; prosternal process flattened, broad, laterally with sparse oval punctures, intermingled with alutaceous microsculpture, in males dorsally space between carinal prosternal striae with dense short setae, in females prosternum asetose; carinal prosternal striae (Fig. 642) only slightly divergent anteriorly, terminating near large and deep apical foveae separated by apex of prosternal prosternal process; lateral prosternal striae carinate, slightly convergent anteriorly, attaining apices of carinal prosternal striae. Lateral costa of antennal groove reaching prosternal process, but not elevated (unlike in Gnathoncus ).

Anterior margin of mesoventrite (Fig. 643) almost straight; discal marginal mesoventral stria well impressed, somewhat carinate; disc flattened, with round punctures separated by about their diameter, in males disc of mesoventrite with moderately long dense yellow setae, mesoventrite in females asetose; meso-metaventral suture indistinct, meso-metaventral sutural stria marked as a row of large punctures.

Intercoxal disc of metaventrite (Fig. 643) in males medially with large setose depression; metaventrite of females asetose, with only slight median longitudinal depression. Disc of metaventrite in both sexes punctate, medially punctures finer and sparser, becoming larger and coarser along lateral margin. Lateral metaventral stria well impressed, carinate, almost straight, not reaching metacoxa; lateral disc of metaventrite (Fig. 644) flattened, with round shallow large punctures fringed with microscopic setae; metepisternum + fused metepimeron (Fig. 644) evenly with much coarser and denser punctation, punctures without setae; lateral metepisternal stria present, deeply impressed and almost complete.

Intercoxal disc of first abdominal ventrite with lateral depressions, almost completely striate laterally; surface of disc with scattered oblong punctation, punctures becoming sparser and finer medially (occasionally almost smooth).

Protibia (Fig. 645) flattened and somewhat dilated, outer margin almost without teeth, with seven–eight widely spaced short denticles; setae of outer row short, moderately dense; setae of median row similarly dense and regular, but even shorter than those of outer row; protarsal groove shallow; anterior protibial stria complete, costate; two thin, rather long tarsal denticles present apically; protibial spur short, straight, growing out from apical protibial margin; apical margin of protibia posteriorly with three to four tiny apical denticles; outer part of posterior surface of protibia (Fig. 645) finely imbricate, with a row of short setae; median part of posterior surface with additional two rows of minuscule setae; posterior protibial stria complete, with scattered minuscule setae turning into five tightly-spaced short and stout denticles near apical margin; inner margin with double row of short lamellate setae.

Mesotibia (Fig. 646) slender, outer margin with a single row of dense thin denticles growing in size apically; setae of outer row sparse, regular, rather dense but short, growing somewhat longer apically; setae of median row irregular, much shorter than those of outer row; posterior mesotibial stria complete; anterior surface of mesotibia with dense row of well sclerotized short setae, with another similar row of much shorter and finer setae situ ated below it; anterior mesotibial stria complete, terminating in three tiny inner anterior denticles; mesotibial spur stout, short; apical margin with two tiny denticles; mesotarsus shorter than mesotibia; claws of apical tarsomere about half its length; metatibia (Fig. 647) basically similar to mesotibia, but denticles of outer margin much sparser than those of mesotibia; claws of apical tarsomere somewhat shorter, about one-third its length.

Male genitalia. Eighth sternite (Figs 651-652) apically longitudinally separated, fused on basal half; vela with sparse microscopic setae, apically with two longer setae; eighth tergite and eighth sternite not fused laterally (Fig. 653). Ninth tergite (Figs 654-655) longitudinally divided medially; spiculum gastrale (Figs 656-657) gradually dilated in most of apical half, basal end slightly dilated, spoon-like. Aedeagus (Figs 658-659) slender, conspicuously slender on apical half; basal piece of aedeagus short, ratio of its length: length of parameres 1: 4; parameres fused along their basal half; aedeagus curved from lateral view (Fig. 659).