Brasilplatus Oliveira, Linzmeier & Konstantinov, 2021

De Oliveira, Denize Wgliana G., Linzmeier, Adelita M. & Konstantinov, Alexander S., 2021, Discovery of the first leaf litter inhabiting flea beetles in Brazil (Coleoptera: Chrysomelidae: Galerucinae) with description of two new genera and three new species, Zootaxa 5068 (1), pp. 99-114 : 100-104

Brasilplatus Oliveira, Linzmeier & Konstantinov , new genus

( Figs 1–13 )

Description. Body 2.5–2.7 mm long and 2.1 mm wide (N=3), elliptical, highly convex in lateral view, pilose ( Figs 1, 2 , 5, 6 ). Color dark brown with whitish and black hair on elytra. Head hypognathous, convex, with frons and vertex forming about 135º angle in lateral view. Vertex densely covered with large setiferous pores ( Fig. 7 ). Supraorbital pore indistinguishable. Antennal calli not separated from rest of head surface, quadrate, punctured as vertex. Midfrontal, suprafrontal, supracallual, suprantennal and supraorbital sulci present. Orbit as narrow as diameter of antennal socket. Interantennal space wide, as wide as the length of first antennomere. Antennal socket small, rounded. Eye small, rounded, slightly projected. Frontal and anterofrontal ridges connected, wide, raised, with anterofrontal ridge extending to clypeal margin, punctured, with setae directed inward ( Fig. 7 ). Frontoclypeal suture present. Clypeus narrow with six setae, four long and two short. Labrum with anterior angles rounded and six setiferous pores bearing long seta. Gena slightly punctured, pilose. First and second maxillary palpomere slightly wider and longer than third; third palpomere conical, with acute apex. Labial palpomeres similar in size, third with acute apex. Antenna with 11 antennomeres; antennomeres VI to X moniliform, densely pilose ( Fig. 8 ).

Pronotum rectangular, densely punctate, wider than long, margined laterally; anterior margin straight; posterior margin slightly concave; anterior and posterior angles well-defined, prominent, with a setiferous pore bearing a long seta. Scutellum triangular, small, smooth and pilose ( Figs 1 , 5 ). Elytra elliptical, with apex narrower. Elytral surface shiny, punctured, pilose with three small, rounded patches of white setae. Punctures forming nine striae between short scutellar and marginal striae; fourth and fifth rows of punctures merge and terminate in posterior half. Interstriae convex ( Figs 4 , 7 ). Basal calli not developed. Humeral calli absent. Epipleura wide, vertical, visible in lateral view, nearly reaching elytral apex. Membranous wings absent. Prosternum narrow, with prosternal process as wide as anterior arms of prosternum; prosternal process extended and widened posteriorly beyond coxa, posteriorly about twice as wide as middle. Procoxa elongate. Procoxal cavities closed posteriorly. Mesoventrite narrow, margined; mesoventral process slightly wider than prosternal process. Metaventrite wide, margined; anterior margin slightly punctured; posterior margin concave medially.

Pro- and mesofemora slightly dilated medially; pro- and mesotibiae subcylindrical, dorsal margins straight, parallel (in dorsal view), slightly narrower at apex (in lateral view), pubescence sparsely distributed; pro- and mesotibial apex with a crown of denticles. First pro- and mesotarsomeres 1.5 times longer than second; second short; third bilobed; fourth tarsomere narrow, as long as second and third together; claws appendiculate. Metafemur greatly enlarged, about 1.5 times longer than wide, longer than metatibia, sparsely pilose, outer side convex, inner side flat ( Figs 2, 3 , 6 ). Metatibia as long as half-length of metafemur, nearly straight, with a preapical projection in lateral view, slightly curved in dorsal view; outer dorsal ridge with preapical projection. Metatibial spur short. Metatarsomeres inserted preapically. First metatarsomere 1.5 times longer than second; second and third short; third not bilobed; fourth globose; metatarsal claws simple.

Abdomen with five visible ventrites. Ventrite V distinctly sexually dimorphic: males with concavity medially on posterior margin and longitudinal medial line; females with last ventrite conical at apex. Pygidium apically exposed. Median lobe simple, tubular, slightly concave in lateral view, apex subtriangular (Figs 9,10). Female sternite eight triangular, medially slightly concave, with setae on apex. Tignum simple, spoon like ( Fig. 13 ). Vaginal palpi parallel, each with sides slightly divergent, apical half of palpi externally rounded and obliquely truncate to rounded apex ( Fig. 12 ). Spermatheca with receptacle, pump and canal distinct ( Fig. 11 ).

Etymology. The generic name is formed from two words, Brasil, referring to the flea beetle’s native country and platus refering to its placement in Monoplatina (from Monoplatus ), masculine.

Type species. Brasilplatus bahianus Oliveira, Linzmeier & Konstantinov , new species.

Remarks. Brasilplatus is similar to Andersonaltica , Apleuraltica Bechyné, 1956 and Ulrica in sharing a rounded-elliptical, convex body, elytral punctures striate, prebasal furrow on pronotum absent, procoxal cavities closed posteriorly and fourth metatarsomere globose, all features of Monoplatina subtribe. From the other monoplatine micro-alticines, Brasilplatus can be differentiated from Andersonaltica (characters in parentheses) by antennomeres VI to X moniliform (antennomeres VII to XI clavate); pronotum without tubercles (pronotum with well-developed tubercles); elytra uniform, without impressions (elytra uneven, impression between basal and humeral calli present, deeper behind basal callus); three small, rounded patches of white setae on elytra (yellowish pubescence), and basal calli not developed (basal calli generally well-developed). From Apleuraltica (in parentheses) Brasilplatus differs by labrum not notched in the middle (anterior margin of labrum notched in the middle); pronotum margined laterally, wider than long, without tubercles (pronotum not margined, almost as wide as long, with three tubercles); elytra convex, without impressions (elytra slightly convex with a deep impression behind basal calli); basal calli not developed (basal calli well-developed); inner and outer dorsal ridges of metatibiae not connected apically (inner and outer dorsal ridges of metatibiae connected apically, forming a preapical dorsal projection above insertion of tarsus, in lateral view). Brasilplatus differs from Ulrica (in parentheses) by antennomeres VI to X moniliform (antennomeres VI to X robust, longer than wide); supraorbital pore indistinguishable (supraorbital pore distinct); pronotum densely and deeply punctured (punctures shallower and sparse); elytra pilose, deeply punctured, with punctures in nine rows (elytra almost glabrous, with smaller and shallower punctures, with punctures in seven rows).

Figures

FIGURES 1–4. Brasilplatus bahianus Oliveira, Linzmeier & Konstantinov, new species, paratype, male, habitus. 1, dorsal view. 2, lateral view. 3, frontolateral view. 4, frontal view.

FIGURES 5–8. Brasilplatus bahianus Oliveira, Linzmeier & Konstantinov, new species, holotype, female. 5, habitus, dorsal view. 6, habitus, lateral view. 7, habitus, frontal view. 8, antenna.

FIGURES 9–13. Brasilplatus bahianus Oliveira, Linzmeier & Konstantinov, new species. 9, median lobe of aedeagus (ventral and lateral views). 10, apex of median lobe of aedeagus (lateral view). 11, spermatheca. 12, vaginal palpi. 13, tignum.