Belladonna Klimaszewski and Chandler, 2023

Klimaszewski, Jan, Chandler, Donald S., Davies, Anthony & Bourdon, Caroline, 2023, Aleocharine rove beetles of New Hampshire, USA: new taxa and new records (Coleoptera, Staphylinidae, Aleocharinae), Zootaxa 5364 (1), pp. 1-141 : 114

Belladonna Klimaszewski and Chandler , gen. n.

Figs. 12a – h , 13a – h

Type species: Belladonna barryi Klimaszewski and Chandler , sp. n.

Diagnosis. This genus is defined by the following combination of characters: tarsal formula 4–5–5, body broadly oval, moderately convex ( Figs. 12a , 13a ); head distinctly narrower than pronotum; pronotum sub-rectangular, distinctly narrower than elytra; elytra at suture about as long as pronotum along midline, posterior margins broadly arcuate; abdomen broad, at base as wide as elytra or nearly so; integument strongly glossy, microsculpture of forebody with hexagonal sculpticells, punctation and pubescence sparse (distance between punctures at least three diameters of a puncture), punctation large and shallowly impressed ( Figs. 12a , 13a ); head strongly narrowed basally behind eyes, and narrowly produced in front of eyes, eyes large and protruding, longer than genae ( Figs. 12a , 13a ); antennomeres I–III strongly elongate, IV–VI subquadrate to slightly transverse, VII–X distinctly transverse ( Figs. 12a , 13a ); maxillary palpi with 4 palpomeres, apical one acicular and almost as long as penultimate one with cluster of apical sensillae; labial palpi with 3 palpomeres; glossa split apically to almost half length; submentum trapezoidal in shape; mesoventrite not carinate, moderately long, broadly triangular, attaining almost middle of mesocoxal cavities, narrow at apex, separated from broadly triangular metaventrite by a short isthmus; male tergite VIII with 2 or 4 teeth (median teeth reduced in N. fortieri ), two larger lateral and two smaller median ones in close proximity ( Figs. 12c , 13c ); median lobe of aedeagus distinct, in lateral view bulbus broadly oval and slightly compressed dorso-ventrad, crista apicalis broad, blade-like, of triangular shape, tubus short with apex narrowly triangular and produced ventrad, its margins slightly sinuate ( Figs. 12b , 13b ); spermatheca S-curved, capsule pitcher-shaped or ovoid with flat apex, median invagination shallow; stem sinuate, evenly elongate or swollen posteriorly ( Figs. 12g , 13g ).

Species of the genus Hydrosmecta C.G. Thomson (presently in Athetini ) also have the blade-like crista apicalis of the bulbus but their body is narrowly subparallel and flattened, with fine punctation and short pubescence, antennomeres V-X are elongate in the majority of species, and male tergite VIII is truncate without teeth. Additionally, Belladonna is externally superficially similar to Trichiusa Casey , with similar proportions of the main body parts, but it has a different type of genitalia and the bulbus of the median lobe of the aedeagus is lacking the blade-like crista apicalis, and male tergite VIII is lacking teeth.

Etymology. The generic name Belladonna derives from Italian belladonna (bella donna, literally “beautiful lady”), altered by folk etymology from Medieval Latin blâdôna (“ nightshade ”), from Gaulish. It relates to the beauty of the species in this genus. The gender is feminine.

Comments. The morphology of the median lobe of aedeagus of the new genus Belladonna is typical for the Tribe Tachusini . Externally the median lobe is particularly similar to those of Gnypeta species. In both genera the median lobe is of a similar form and bears a triangular crista apicalis of the bulbus.

The genus Belladonna differs from Gnypeta by the large and sparse punctation of the forebody (distance between punctures at least three diameters of a puncture), and antennomeres VIII–X distinctly transverse ( Figs. 12a , 13a ), and the differently shaped median lobe of the aedeagus and the spermatheca. Additional molecular studies are needed to confirm the true relationships of the species.

Key to Nearctic species of Belladonna

1. Male tergite VIII with four sharp apical teeth, two distributed laterally and two medially, median teeth smaller ( Fig. 12c ); apical part of median lobe of aedeagus broadly triangular, elongate and sinuate ( Fig. 12b ); spermathecal capsule pitcher-shaped in lateral view, stem swollen posteriorly ( Fig. 12g ).................. Belladonna barryi Klimaszewski and Chandler sp.n.

- Male tergite VIII with two sharp apical teeth distributed laterally, median teeth not apparent ( Fig. 13c ); apical part of median lobe of aedeagus narrowly elongate and sinuate ( Fig. 13b ); spermathecal capsule ovoid in lateral view, stem more or less even in width ( Fig. 13g )........................................ Belladonna fortieri Klimaszewski and Chandler sp.n.

Figures

FIGURE 12a–g. Belladonna barryi Klimaszewski and Chandler, sp. n.: (a) habitus in dorsal view; (b) median lobe of aedeagus in lateral view; (c) male tergite VIII; (d) male sternite VIII; (e) female tergite VIII; (f) female sternite VIII; (g) spermatheca. Scale bar for habitus = 1mm; remaining scale bars = 0.2mm.

FIGURE 13a–g. Belladonna fortieri Klimaszewski and Chandler, sp. n.: (a) habitus in dorsal view; (b) median lobe of aedeagus in lateral view; (c) male tergite VIII; (d) male sternite VIII; (e) female tergite VIII; (f) female sternite VIII; (g) spermatheca. Scale bar for habitus = 1mm; remaining scale bars = 0.2mm.