Hypocaccus (Baeckmanniolus) virescens Thérond, 1963

Lackner, Tomáš, 2013, Hypocaccus (Baeckmanniolus) laevis Thérond, 1963 is not synonymous with H. (B.) virescens Thérond, 1963 (Coleoptera: Histeridae: Saprininae), Zootaxa 3731 (1), pp. 183-192 : 187-191

Hypocaccus (Baeckmanniolus) virescens Thérond, 1963

( Figs. 10–28 )

Baeckmanniolus virescens Thérond, 1963: 110 .

Hypocaccus (Baeckmanniolus) virescens: Mazur, 1984: 100 ; 1997: 263; 2011: 204.

Type locality. Somalia, Banaadir [=Benadir] region: Muqdisho [=Mogadiscio].

Material examined. Holotype (NHMB), ♀, mounted on its side on a triangle point, left metatarsus missing, with printed label: “Umgeb. Mogadiscio / Somalia / leg. C. Koch, VII.59 ”; another label (printed-written): “J. Thérond det. 1962 / Baeckmanniolus / virescens / nov. sp.”; with another red label: “ HOLOTYPUS / Baeckmanniolus / Thérond, 1963 / label attached by / T. Lackner 2008”; paratype (NHMB), ♂, with genitalia mounted in Canada Balsam under the specimen, mounted on its side on a triangle point, right mesotarsus broken off, left protibia broken off and glued on the point, tarsus missing, same data as Holotype, with another (pencil hand-written) pink label: “D07-063”; and another pink label, printed-written: “ Paratype / Baeckmanniolus / virescens / Thérond, 1963 / attached by T. / Lackner 2008”; paratype (MNHN), ♀, mounted on its side on a triangle point, right antennal club broken off, same data as Holotype, with another (pencil hand-written) pink label: “D07- 0 64 PT”; and another pink label, printed-written: “ Paratype / Baeckmanniolus / virescens / Thérond, 1963 / attached by T. / Lackner 2008”.

Re-description. Body length: PEL: 2.00– 2.15 mm; APW: 0.75–0.85 mm; PPW: 1.50–1.60 mm; EL: 1.20– 1.25 mm; EW: 1.55–1.65 mm. Body ( Figs. 10–11 ) rectangular oval, convex, cuticle dark brown, with a slight greenish hue; legs, mouthparts and antennal scape light brown. Antennal scape ( Fig. 13 ) carinate on lower side, upper margin rounded, with four short setae; club without visible articulation; sensory structures of the antenna not inspected.

Mouthparts. Mandibles ( Fig. 13 ) stout, with rounded outer margin, upper margin carinate; disk of labrum ( Fig. 12 ) somewhat convex medially, two well-impressed pits present, with two well-sclerotized setae arising from each; width of terminal labial palpomere about one-third its length; mentum ( Fig. 14 ) square shaped, posterior angles slightly produced, with a tiny notch in middle of anterior margin surrounded by several setae; lateral margins with few shorter ramose setae; disk of mentum with several short setae. Cardo of maxilla with two short setae; stipes ( Fig. 14 ) triangular, with three longer setae; terminal maxillary palpomere somewhat thickened, its width slightly shorter than half its length, approximately twice as long as penultimate; other parts of the mouth not examined.

Clypeus + frons. Clypeus ( Fig. 13 ) rectangular, somewhat depressed medially, anterior margin elevated; frontal stria of head well impressed, straight, carinate, continued as strongly carinate supraorbital stria. Frons ( Fig. 13 ) smooth, with two well marked chevrons; eyes flattened, almost invisible from above.

Pronotum. Pronotal sides ( Fig. 10 ) moderately convergent anteriorly, apical angles rounded; anterior emargination for head moderately deep, almost straight in middle; marginal pronotal stria complete, slightly carinate; pronotal disk entirely smooth except for a single row of round punctures along base and a small cluster of scattered and fine punctures near anterior angles; pronotal hypomeron smooth; scutellum small, visible.

Elytra + propygidium and pygidium. Elytral epipleura almost smooth; marginal epipleural stria complete, very fine; marginal elytral stria well impressed, continued as weakened and complete apical elytral stria. Humeral elytral stria well impressed on basal third; inner subhumeral stria shortly present medially; elytral disk with four well impressed dorsal elytral striae 1-4, in deep punctures, striae 1-2 slightly surpassing elytral half, 3-4 reaching apically slightly further, fourth one well connected with sutural elytral stria; sutural elytral stria well impressed and complete, apically connected with apical elytral stria. Punctuation of elytral disk limited to posterior third, along sutural elytral stria reaching elytral half, few punctures enter third elytral interval (between third and fourth elytral stria); punctures deep and regular, separated by about twice their own diameter. Punctuation of propygidium similar to that of elytra, but finer and sparser, punctuation of pygidium even finer and sparser; pygidial apex smooth.

Prosternum. Anterior margin of median portion of prosternum ( Fig. 15 ) rounded, prosternal foveae deeply impressed. Prosternal process concave, with sparse punctures of irregular size; interspaces with isodiametric structures; lateral prosternal striae well impressed, carinate, convergent anteriorly, united in front; carinal prosternal striae slightly carinate, weakly divergent between procoxae, thence almost parallel, vaguely united in front.

Meso-metaventrite + metepisternum and abdomen. Anterior margin of mesoventrite deeply emarginated medially; marginal mesoventral stria deeply impressed, carinate; meso-metaventral suture weakly impressed, straight. Disk of mesoventrite flat, smooth; intercoxal disk of metaventrite smooth, basally covered with irregular sparse microscopic punctures, especially in the area around metacoxa. Lateral metaventral stria well impressed, carinate on outer margin, slightly bisinuate, stopping near metacoxa. Lateral disk of metaventrite ( Fig. 16 ) excavate, with shallow sparse punctures of various sizes fringed with very short setae; metepisternum with coarser and denser punctures fringed with minute setae. Intercoxal disk of the first abdominal ventrite completely striate laterally; almost smooth, clothed only with sparse minute punctures along basal margin.

Legs. Protibia ( Fig. 17 ) dilated, outer margin with three low triangular teeth topped by small rounded denticle diminishing in size in proximal direction, followed by one very low tooth topped by minuscule denticle and another minute denticle; outer row of setae sparse, setae well-distanced from each-other, rather short; protibial stria complete, terminating in three minute tarsal denticles; median row of setae regular, its course parallel to that of protibial stria, setae shorter than those of outer row; protibial spur tiny, growing out from anterior margin of protibia; groove for reposing tarsi deep. Outer part of posterior surface of protibia ( Fig. 18 ) with irregular short rugae; divided from median part by a definite boundary and three minute denticles; posterior protibial stria wellmarked, complete, terminating in four minute inner posterior denticles; apical margin of protibia ventrally with two minuscule apical denticles; inner row of setae sparse, not lamellate. Mesotibia slender, outer margin with two dense rows of denticles each growing in length in apical direction, outer row of setae sparse, setae long, well-sclerotized, their length approximately on par with the row of longer denticles of outer mesotibial margin; median row of setae regular, setae much shorter and weaker than those of outer row; anterior surface of mesotibia glabrous; anterior mesotibial stria not complete apically; mesotibial spur long; claws of apical tarsomere bent, longer than half its length. Metatibia ( Fig. 19 ) in all aspects similar to mesotibia but more slender and denticles on outer margin sparser; claws of apical tarsomere bent, longer than half its length.

Male genitalia. Eighth sternite ( Figs. 20–21 ) completely separated medially, apically with small velum and a single tiny seta on each half; eighth sternite and tergite fused laterally ( Fig. 22 ). Morphology of 9th tergite ( Figs. 23–24 ) typical for the subfamily; spiculum gastrale ( Figs. 25–26 ) expanded on both ends; aedeagus ( Figs. 27–28 ) curved apically; almost parallel, basal piece short, ratio of basal piece: parameres approximately 1:4; parameres of aedeagus fused along their basal three-fourths.

Comment. Thérond (1963) placed this species in the subgenus Baeckmanniolus of the genus Hypocaccus . Members of this subgenus are defined by a completely glabrous pronotum and at least three rows of denticles on the outer margin of the metatibia (Lackner 2010: 140). However, H. (B.) virescens has a small cluster of sparse and fine punctures on the anterior pronotal angles as well and possesses only two rows of denticles on outer margin of metatibia. Both these characters should, therefore, place it in the nominative subgenus of the genus Hypocaccus . Because the limits of both subgenera are unclear and there are other species currently classified as Baeckmanniolus that exhibit pronotal punctuation (e.g. H. (B.) varians )), the taxonomic rank of H. (B.) virescens is left unaltered pending revision of both subgenera.

Biology. As with the preceding species.

Distribution. Somalia, Banaadir region: Muqdisho ( Fig. 29 )

Acknowledgements

I am indebted to my former supervisor Masahiro Ôhara (Sapporo, Japan) for various help during my stay in Sapporo. Thanks are due to the curators of the institutes mentioned above for their help with the specimens. My wife Pepina Artimová has drawn the distributional map of both species using Adobe Illustrator CS5 and I am deeply indebted to her for that. I would like to thank one anonymous reviewer of this manuscript as well as the editor for Histeroidea at Zootaxa for their critical remarks, corrections and language check that resulted in a better quality of this work. This research was supported by the Internal Grant Agency (IGA n. 20124364) Faculty of Forestry and Wood Sciences, Czech University of Life Sciences Prague.

Figures

FIGURE 29. Distributional map of Hypocaccus (Baeckmanniolus) virescens Thérond, 1963 and H. (B.) laevis Thérond, 1963.

FIGURES 10 – 19. Hypocaccus (Baeckmanniolus) virescens Thérond, 1963, SEM micrographs: 10 — habitus, dorsal view; 11 — ditto, ventral view; 12 — labrum, dorsal view; 13 — head, dorsal view; 14 — mentum, ventral view; 15 — prosternum; 16 — lateral disk of metaventrite + metepisternum; 17 — protibia, dorsal view; 18 — ditto, ventral view; 19 — metatibia, dorsal view.

FIGURES 20 – 28. Hypocaccus (Baeckmanniolus) virescens Thérond, 1963, male genitalia: 20 — eighth sternite and tergum, ventral view; 21 — ditto, dorsal view; 22 — ditto, lateral view; 23 — ninth and tenth tergites, dorsal view; 24 — ditto, lateral view; 25 — spiculum gastrale, ventral view; 26 — ditto, lateral view; 27 — aedeagus, dorsal view; 28 — ditto, lateral view.