Belladessus minutopunctatus Benetti, Short, and Hamada, 2021

Benetti, Cesar J., Z. Short, Andrew Edward & Hamada, Neusa, 2021, First Report of Belladessus Miller and Short, 2015 from Brazil with Description of Two New Species (Coleoptera: Dytiscidae: Hydroporinae: Bidessini), The Coleopterists Bulletin 75 (2), pp. 339-345 : 342-344

Belladessus minutopunctatus Benetti, Short, and Hamada , new species zoobank.org/ urn:lsid:zoobank.org:act:9AC8DDB9-3C95-40D5-849A-B95C8E78A956 ( Figs. 2 , 4 , 7–8 )

Type Material. Holotype (♀): Brazil, Federal District, Brasília , “Fazenda Água Limpa, Córrego Bonito” (15°57′08.7′′S, 047°58′21.0′′W), 1,091 m.a.s.l., 19.vi.2017, leg. N. Hamada, G. R. Desidério and G. Amora ( INPA).

Description. Measurements (n = 1): TL = 2.23 mm, GW = 1.06 mm, PW = 0.94 mm, HW = 0.69 mm, EW = 0.42 mm, TL/GW = 2.1, HW/EW = 1.63. Body oblong, flattened on elytral base, between the middle of elytron and suture; laterally slightly curved, almost parallel in anterior two-thirds of elytra; apex rounded, a little tapering; outline slightly discontinuous between pronotum and elytra. Coloration: Head dark brown; antennae and mouthparts yellow; pronotum dark yellow; elytra black (dark brown) with two large yellow maculae, the first wider, broad, located from elytral margin almost to the suture, the second smaller, subapical, V-shaped; propleuron, pronotal hypomeron and elytral epipleuron dark yellow; metaventrite, metacoxae and abdominal ventrites dark orange; pro- and mesolegs, metatrochanter and metafemur dark yellow; metatibia and metatarsus orange. Sculpture and structure: Head transversely broad, anterior clypeal margin broadly curved, distinctly expanded and broadly margined; surface with extremely fine, sparse punctures, finer than on pronotum, unpunctured on posterior margin, behind eyes; with weak microreticulation; occipital line absent; antennomeres 1–2 moderately elongate, 1.5 times longer than antennomeres 3–10 which are short and broad, 11 elongate, 1.5 times longer than 3–10, narrow. Pronotum broad, widest at anterior third; lateral bead fine and continuous; surface shiny, more than on elytra, giving rough aspect, covered with extremely fine punctures, coarser than punctures on elytra. Pronotal striae long, reaching more than half of pronotal length, almost straight. Elytron about 2.9 times longer than wide; lateral margins of elytra slightly curved; elytral striae long, extending to almost half of elytral length; sutural stria absent; surface with dense and very fine punctures, finer than punctures on head and pronotum, giving a rough aspect; with two rows of thicker punctures near the elytral striae. Elytral epipleuron very fine, with anterior margin strongly curved, without transverse carina at humeral angle; evenly narrowed towards apex; surface with fine punctures. Prosternum medially tectiform and setose; prosternal process slender, lateral margins parallel; carinate, medially longitudinally canaliculate; apex pointed. Metaventrite with fine punctures. Abdomen: Ventrites 4 and 5 with a pencil of large setae in the middle; surface shiny, with few fine punctures; ventrite 6 margined (impressed), with apex broadly pointed. Legs shiny, relatively impunctate; metacoxae with fine punctures; metatrochanter broad, slightly offset from midline of metafemur; metacoxal process with fine punctures.

Differential Diagnosis. The new species can be differentiated from the other species in the genus by: punctures on elytra fine and dense, much finer than in other Belladessus species, giving the surface a rough aspect; anterior clypeal margin more distinctly modified, with the marginal bead thicker than in B. espinhasso ; body shape more elongate (TL/ GW = 2.1) than in B. femineus , B. puella and B. soqtapata (TL/GW = 1.7–1.8), almost parallel near basal third of elytra; pronotal and elytral striae long and straight, longer than in other Belladessus species; elytral epipleura thinner, very fine, with anterior margin strongly curved. Belladessus minutopunctatus has a unique elytral color pattern, with a very large basal macula covering almost entire surface of basal third and in having body flattened on elytral base, between the midwidth of elytron and suture. From B. soqtapata the new species differs also in having the pronotum entirely dark orange, without a dark band on posterior margin, while in B. soqtapata the pronotum is dark brown along posterior margin of pronotum.

Etymology. The name minutopunctatus is an adjective referring to the fine punctures on the dorsal and ventral surfaces of the new species.

Distribution and Habitat. This species is known only from the type locality in Brasília, Federal District in central Brazil, situated on a plateau in the “cerrado” tropical savanna biome. The specimen was collected in a stream at 1,091 m elevation, in sandy and rocky substrates ( Figs. 7–8 ).

Figures

Figs. 1–3. Belladessus species, dorsal habitus.1) B.espinhasso, new species, holotypefemale; 2) B.minutopunctatus, new species, holotype female; 3) B. femineus. Scale bars = 1 mm.

Fig. 4. Belladessus species, known distributions. Square symbols represent previous records, circular symbols rep- resent new records.

Figs. 5–10. Habitat of Belladessus species. 5–6) B. espinhasso, new species, Brazil: Minas Gerais State, Monte Azul County, “Serra do Espinhaço”, stream; 7–8) B. minutopunctatus, new species, Brazil: Federal District, Brasília, “Fazenda Água Limpa, Córrego Bonito”; 9–10) B. femineus, Brazil: Roraima State, Amajari County, “Serra do Tepequém, igarapé na ponte, antes da Vila a direita”.