Benedictus sagittalis, Damaška & Aston, 2019

Damaška, Albert F. & Aston, Paul, 2019, Leaf litter and moss-inhabiting flea beetles of Hong Kong (Coleoptera: Chrysomelidae: Alticini), Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 59 (1), pp. 151-161 : 152-153

Benedictus sagittalis sp. nov.

( Figs 1 A–I)

Type locality. China, Hong Kong, New Territories, Castle Peak.

Type material. HOLOTYPE: ♁, ‘ China: Hong Kong – New Territories ; Castle Peak, pitfall trap, 30. vi. – 3. vii. 2015 R. Ho Lee et Y. Luo lgt.’ ( NMPC) . PARATYPES: 2 ♁♁ 2 ♀♀, same locality label as holotype (1 ♁ 1 ♀ USNM, 1 ♁ SYSU, 1 ♀ PCPA); 1 ♁, ‘ China: Hong Kong – New Territories, Tai Mo Shan, pitfall trap; 9. – 12. vi. 2015, R. H. Lee & Y. Luo lgt. // VOUCHER SPECIMEN no.AFD-024 DNA isolated 2017 ex coll.A. F.Damaška’ ( AFCD); 1♀, ‘ China: Hong Kong – New Territories, Tai Mo Shan, pitfall trap; 9. – 12. vi. 2015, R. H. Lee & Y. Luo lgt. // VOUCHER SPECIMEN no. AFD-023 DNA isolated 2017 ex coll. A. F. Damaška’ ( NMPC).

Differential diagnosis. This species belongs to the genus Benedictus as it has a distinct antebasal transverse impression and posteriorly open procoxal cavities, i.e. a combination of characters unique for Benedictus among apterous moss and leaf litter inhabiting flea beetles in Asia. Benedictus sagittalis sp. nov. is easily distinguishable from all other species of the genus in having a completely unique, arrow-like apex of the aedeagus ( Fig. 1H ).

Description. Habitus ( Figs 1 A–C). Body 1.7 mm long, 1.1 mm wide in maximum, oval in dorsal view, strongly convex in lateral view, 0.8 mm high in maximum. Color of all body surfaces light brown, eyes black, basal margins of pronotum and elytra somewhat darkened.

Head hypognathous, triangular. Frontal calli subtriangular, distinct, but feebly projecting, nearly connected to each other. Interantennal space flat, projecting, finely chagrined. Vertex shiny, impunctate. Antennae 11-segmented. Antennomere I wide, antennomere II bulbose, antennomere III thinner and shorter than I and II. Antennomeres IV–XI gradually widening. Frontal ridge strongly projecting, wide in interantennal space and strongly narrowing below. Space on sides of frontal ridge strongly and widely depressed, depressions finely chagrined, surrounded anteriorly by longitudinal edges between antennal insertions and anterior margins of clypeus. Labrum with shallow notch in middle of anterior margin, dark brown, long, about 1.2 × as wide as long, with four long setae. Anterior margin of clypeus darker than head, clypeus with six setae (two pairs of setae laterally and one pair in the middle of clypeus).

Thorax. Pronotum very convex, 1.3 × as wide as long, anterolateral and posterolateral margins of pronotum projecting, posterolateral corners of pronotum sharp, basal pronotal transverse impression deep, with row of punctures. Elytra strongly convex, with 11 well-developed rows of small punctures. Basal part of epipleura very wide, strongly narrowing to elytral apex. Legs light brown, metatibia straight, apex of metatibia pilose, metatibial spine slender and short, metatarsomere I about 0.8× as long as metatarsomeres II and III combined.Anterior coxal cavities open, intercoxal prosternal process surpassing coxae and feebly widening posteriorly.

Abdomen with five visible ventrites, ventrite I nearly as long as ventrites II–V combined. Ventrite II slightly longer than III, ventrites III and IV equally long. Ventrite V as long as ventrites II and III combined.

Genitalia. Aedeagus ( Figs 1 H–I) long, with basal part slightly wider than apical, apex of aedeagus with distinct pointed arrow-like ending. Spermatheca ( Fig. 1D ) with receptacle bulbose, pump wide and long. Duct directing posteriorly, forming three round loops and then directing anteriorly. Vaginal palpi ( Fig. 1G ) long, slender, converging apically. Tignum simple ( Fig. 1F ).

Etymology. The name is inferred from Latin sagitta meaning ‘arrow’, and refers to the distinctive shape of the apex of the aedeagus. Adjective.

Biology. The specimens were found in pitfall traps in mountain areas. Other species of Benedictus are considered to be leaf litter or moss-inhabiting. We cannot clearly justify B. sagittalis is a moss-inhabitant, but it can be considered at least as a ground-living, leaf litter-inhabiting forest beetle, as it was found only in pitfall traps.

Figures

Fig. 1. Morphology of Benedictus sagittalis sp. nov.A – habitus in dorsal view; B – habitus in lateral view; C – habitus in ventral view; D – spermatheca; E – apical sclerite; F – tignum; G – vaginal palpi; H – aedeagus in dorsal view; I – aedeagus in lateral view.