Vatellus yanomami, Braga, Rafael Benzi & Ferreira-Jr, Nelson, 2016

Braga, Rafael Benzi & Ferreira-Jr, Nelson, 2016, Vatellini Sharp (Coleoptera, Dytiscidae) from Brazil: two new species, new records, and a checklist, Zootaxa 4111 (1), pp. 77-91 : 82-85

Vatellus yanomami sp. nov.

( Figs 18–34 )

Type locality. Brazil, Amazonas State, Barcelos Municipality.

Type-material. Holotype: ♂ ( INPA) “ Brasil, AM, Barcelos, Igarapé do Reginel, #21, 10 /VIII/2009, folhiço com raízes, Ferreira-Jr N.” [01°02’30,98”S 62°50’09,20”W] “ Vatellus yanomami Braga e Ferreira-Jr., DET. BRAGA R.B. 2014” “Htipo” [red plastic label]. Paratypes: 44 ex. ( INPA) “ Brasil, AM, Barcelos, Igarapé do Reginel, #21, 10 /VIII/2009, folhiço com raízes, Ferreira-Jr N.” [01°02’30,98”S 62°50’09,20”W] “ Vatellus yanomami Braga e Ferreira-Jr., DET. BRAGA R.B. 2014” “Ptipo” [red plastic label]; 5 exs. ( DZRJ 5804) “ Brasil, AM, Barcelos, Sítio do Sr. Miranda, Comunidade Ukuki, Poça da mata, trilha para piaçaval, 25/VII/2009, A. Pés” [00°48’00,28”N 63°29’22,92”W]; “ Vatellus yanomami Braga e Ferreira-Jr., DET. BRAGA R.B. 2014” “Ptipo” [red plastic label] “5804” [blue plastic label]; 2 ex. ( DZRJ 5806) “Br, AM, Barcelos Regynel, 1o ordem, A114, Água Branca, 10/VIII/2009, Nessimian J.L.” [01°02’30,98”S 62°50’09,20”W] “ Vatellus yanomami Braga e Ferreira-Jr., DET. BRAGA R.B. 2014” “Ptipo” [red plastic label] “5806” [blue plastic label]; 26 exs. ( DZRJ 5807) “ Brasil, AM, Barcelos, Igarapé da fazenda, #22, 11 /VIII/2009, Folhiço na margem com sedimento, Nessimian J.L.” [01°02’57,70”S 62°49’17,76”W] “ Vatellus yanomami Braga e Ferreira-Jr., DET. BRAGA R.B. 2014” “Ptipo” [red plastic label] “5807” [blue plastic label].

Diagnosis. Ver y large size. Habitus as in Fig. 18 . Dorsally dark brown, ventrally brown to dark brown. Pronotum densely punctate except for anterior margin and two transverse areas on each side of midline smooth ( Fig. 19 ); male mesotrochanteres with two incisions each with a well developed setal brush ( Fig. 21 ). Ventrite VI with apical lobe produced with a brush of golden setae at apex ( Fig. 26 ). Apex of median lobe with a small central incision ( Fig. 29 ); dorsoapical margin of lateral lobes with area of dense, fine, elongate setae; curved setae absent ( Fig. 27 ).

Description. (Based on holotype). Measures. Total length 6.76 mm; maximum width 3.25 mm; pronotum length 1.16 mm; elytral length 4.80 mm; maximum width of pronotum 2.08 mm.

Habitus ( Fig. 18 ). Body outline discontinuous in dorsal view, lateral elytral margins lightly rounded, dorsoventrally moderately flattened.

Coloration ( Fig. 18 ). Dorsally dark brown. Ventrally head brown, hypomeron and mesoventrite brown, metaventrite dark brown to almost black; legs with coxae and trochanteres dark brown to almost black, femora, tibiae and tarsi brown; abdominal ventrites brown.

Sculpture and structure ( Figs 19–26 , 31 ). Head surface smooth with fine punctation from clypeus to region between eyes, surface posterior to eyes microreticulate; anterior clypeal margin distinctly produced; eyes relatively small, rounded. Pronotum densely punctate except for anterior margin and two transverse areas on each side of midline smooth, shiny and impunctate; surface between punctures microreticulate; punctures with short, fine, white setae ( Fig. 19 ); pronotum cordate with shagreened margins, transverse sulcus absent. Elytra densely punctate as pronotum, surface between punctures smooth and shiny. Prosternum moderately short, setose; prosternal process broad, medially concave, lateral margins rounded, apex narrowly pointed; mesotrochanteres with two incisions, each with a well developed setal brush; ventral margin of base of mesofemora with brush of weakly developed setae ( Fig. 21 ); metaventrite coarsely punctate, surface between punctures shiny, smooth, midline area ventrally produced; metacoxae with lateral portion relatively coarsely punctate, medial portion finely and densely punctate, metacoxal lines strongly divergent anteriorly, approximate posteriourly ( Fig. 20 ); metatrochanteres short, rounded, rectangular-shaped ( Fig. 23 ), metatarsal claws finely dentate. Abdominal ventrites finely punctate laterally, surface smooth, shiny; ventrite VI with apical lobe produced, flattened, apically rounded, with a brush of golden setae at apex ( Fig. 26 ); speleum relatively short, broad basally, sides almost straight, narrow apically, apex strongly bent to venter ( Fig. 31 ).

Male genitalia ( Figs 27–30 ). Median lobe in lateral view evenly curved, narrowed apically, apex narrowly sharp, without subapical setae, basal portion broad, robust ( Fig. 28 ); in ventral view almost straight, narrow, apically with lateral margins evenly converging to rounded apex ( Figs 29–30 ), apex with a small central incision ( Fig. 29 ). Lateral lobes with apical portion narrow, margins almost parallel, apex rounded, dorsoapical margin with area of dense, fine, elongate setae; curved setae absent ( Fig. 27 ).

Intraspecific variation. Small differences in size; total length 6.60–7.24 mm; maximum width 3.00–3.68 mm; pronotum length 1.00–1.16 mm; elytral length 4.80–5.20 mm; maximum width of pronotum 1.95–2.24 mm.

Sexual dimorphism. Male mesotrochanteres with two incisions each with a well developed setal brush ( Fig. 21 ); in female mesotrochanteres without incision, with a single brush of setae ( Fig. 22 ). Male pro- and mesotarsomeres visibly more expanded respect in female ( Figs 24–25 ).

Female genitalia ( Figs 32–34 ). Gonocoxosternites very broad, robust, apical angle slightly rounded, anterior margin slightly concave, medial margin convex, anterior lobe long and slender ( Fig. 34 ). Gonocoxae elongate, very slender, almost straight, apex relatively narrowly rounded, apodeme elongate and slender ( Fig. 33 ). Receptacle semispherical, almost half the size of spermatheca; spermatheca spherical, triangular process large, very broadly expanded ( Fig. 32 ).

Etymology. The species name refers to masculine and feminine noun “ Yanomâmi ”, name of the indigenous people present in the area of origin of the type material.

Taxonomic notes. This species can be distinguished from other members of the genus by its large size, being only comparable to V. sahlbergi ( Sharp, 1882) , from which it differs in several characters. For example, the speleum is abruptly narrowed at the apex and two setal tufts are present on male mesotrochanteres of V. yanomani , whereas in V. sahlbergi the speleum is regularly narrowed and a single setal tuft is present on male mesotrochanteres. The new species also exhibits some characters of the V. grandis clade sensu Miller (2005), such as the dense shagreenation of the pronotum, except for small lateral patches, the anteromedial portion of the metaventrite distinctly swollen ventrally, and a small female receptacle. However, it lacks a distinct tuft of long and curved setae on the dorsoapical margin of the male lateral lobe, this character is present in all species of the V. grandis clade, with exception of V. bifenestratus . The female genitalia resemble those of V. grandis but with a more rounded receptacle, and the male genitalia have similarities to those of V. bifenestratus , although the apex of the median lobe is regularly narrowed, not abruptly narrowed as in V. bifenestratus .

Geographic distribution. So far known only from the Amazonas State in Brazil.

Figures

FIGURES 18 – 26. Vatellus yanomami. 18. Dorsal habitus, 19. Dorsal punctation; 20. Metacoxal process; 21. Male left mesotrochanter and mesofemur, ventral view 22. Female left mesotrochanter and mesofemur, ventral view, 23. Left metatrochanter and metafemur, ventral view; 24. Male left mesotarsus (a) and protarsus (b) ventral view; 25. Female left mesotarsus (a) and protarsus (b) ventral view; 26. Male ventrite VI, ventral view. Scales: Figs. 18 – 19 = 1.0 mm, Figs. 20 – 26 = 0.5 mm.

FIGURES 27 – 34. Vatellus yanomami. 27 – 30 Male genitalia; 27. Right lateral lobe, lateral view; 28. Median lobe, lateral view; 29. Apex of median lobe, ventral view; 30. Median lobe, ventral view; 31. Speleum and ventrites V and VI, dorsal view; 32 – 34 Female genitalia; 32. Spermatheca and associated structures, ventral view (a) and dorsal view (b); 33. Gonocoxae, ventral view; 34. Gonocoxosternites, ventral view. Scales: Figs. 27 – 30 and 32 – 34 = 0.1 mm, Fig. 31 = 0.5 mm.