Xenelmis sinecarina, Sampaio, Brunno Henrique Lanzellotti, Passos, Maria Inês Da Silva Dos & Ferreira-Jr, Nelson, 2015

Sampaio, Brunno Henrique Lanzellotti, Passos, Maria Inês Da Silva Dos & Ferreira-Jr, Nelson, 2015, New species and new records of Xenelmis Hinton (Coleoptera: Elmidae) from Southeastern Brazil, Zootaxa 3936 (1), pp. 115-122 : 116-117

Xenelmis sinecarina sp. nov.

( Figs 1 a–c)

Diagnosis. This species is distinguished by the combination of the following characteristics: (1) pronotum with a pair of median carinae, formed by a row of granules; (2) elytra posteriorly convergent with carinae of similar length on fifth and seventh elytral intervals; (3) flat scutellum; (4) parameres long and wide, with apical portion narrowed.

Description. Holotype male: total length 1.65 mm; head greatest width 0.35 mm, length 0.25 mm; pronotum greatest width 0.64 mm, length 0.50 mm; elytra greatest width 0.88 mm, length 0.90 mm. Body dark brown, appendages lighter brown.

Surface of head microsculptured, slightly iridescent. Anterior margin of clypeus medially truncate; frontoclypeal suture feebly sinuate, medially and laterally oblique; antennae filiform, eleven-segmented, inserted between eyes, just posterior to fronto-clypeal suture; last antennomere fusiform, as long as segments IX–X together. Eyes ovate, separated by distance of the greatest width of one eye. Pronotum wider than long, anterior margin strongly convex medially, antero-lateral angles inconspicuously pronounced, lateral margin arcuate, widening posteriad, posterior margin three-arcuate—one concavity on each side of a median one in front of scutellum. Surface of pronotum with some sparse granules, coarser on anterior half and laterally; pair of median carinae made by row of granules beginning on posterior margin, extending up to anterior fourth, with slight constriction on anterior third; sublateral carina on each side, beginning on posterior margin, extending toward anterior margin, but fading on anterior fourth; inconspicuous lateral carina on posterior half near lateral margin.

Elytra: 1.2x as long as wide, anterior margin of each elytron sinuate, humerus acute, lateral margin crenate converging posteriorly up to the rounded and slightly projected apices, apex feebly projected and rounded; surface moderately convex, with well defined striae, made by row of punctures; six striae on disc plus one sublateral; fifth and seventh interval carinate—inner carina slightly longer than outer; interstrial intervals with sparse fine recumbent setae; epipleura smooth, widening up to projected apices of elytra; scutellum flattened, as long as wide, with anterior margin and apex rounded.

Prosternum subtrapezoidal, anterior margin slightly concave, antero-lateral angles rounded, lateral margin oblique; prosternal process wide, extending beyond procoxa, with feebly rounded posterior margin. Hypomeron tomentose. Mesosternum projected toward prosternum, with wide and short groove for reception of prosternal process. Mesepimeron and mesepisternum tomentose and finely granulose. Metasternum feebly depressed on anterior portion; disc finely punctuate. Metepisternum and metepimeron tomentose.

Legs: femur with fine granules; tibia with fringe of tomentum, metatibia with row of spines; tarsi I–IV with tufts of seta near base, last tarsomere with single dorsal seta.

Abdomen: ventrites diminishing in length and width from first to fourth; lateral margin of ventrites rounded; ventrite I with some sparse punctures; ventrite V as long as III–IV together, posterior margin rounded.

Male genitalia with parameres elongate and wide on anterior half, narrowing toward apex, with few sensilla on apex. Median lobe elongate, wide, slightly longer than parameres, feebly constricted near apex, with pair of long setae. Phalobase asymmetric and longer than median lobe.

Variation. Female externally similar to male. Color may vary among specimens. Total body length varies between 1.53–1.65 mm; head greatest width 0.24–0.38 mm; pronotum greatest width 0.64–0.68 mm and length 0.50–0.59 mm; and elytra greatest width 0.84–0.94 and length 0.88–0.99 mm.

Comparative notes. Xenelmis sinecarina sp. nov. has a pair of sublateral carinae and a pair of median carinae on pronotum, these are characteristics of X. granata and X. micros groups, respectively. This species does not have robust hind femora, neither the male genitalia has apices of parameres turned outward like in X. granata . The new species differs from X. micros by median lobe of male genitalia not being wide at base like the one of X. micros .

Type material: Holotype. Male. Brazil, Rio de Janeiro state, Macaé municipality, Frade, Rio São Pedro (Córrego Sibéria), SP03, 22º13'45,1"S 42º07'39,6"W, 426m, 20-III-2009 J.L. Nessimian, G.A. Jardim, I.C. Gonçalves, B.H.L. Sampaio, V.P. Alecrim, G. Lefebvre leg. [ DZRJ Coleoptera-5624]; Paratypes: 1 female— Nova Friburgo municipality. Macaé de Cima, Rio Bonito, Fazenda São Sebastião—RB01, 22º24'18,8"S 42º27'55,3"W, 1038m, 30-XI-2008, B.H.L. Sampaio leg. [ DZRJ Coleoptera-5616]; 1 specimen—Rio Bonito de Lumiar, Ramalhete, afluente de 3ª ordem do Rio Bonito—RB08, 22º24'38,2"S 42º20'38,6"W, 669m, 0 6-III-2009, A.L.H. Oliveira leg. [ DZRJ Coleoptera-5617]; 13 specimens—Rio Bonito de Lumiar, afluente de 3ª ordem do Rio Bonito, casa do Sr. Caizé—RB21, 22 º24'15,3"S 42º26'46,2"W, 863m, 03-IV-2009, B.H.L. Sampaio leg. [ DZRJ Coleoptera- 5618]; 3 specimens—Rio Bonito de Lumiar, Rio Bonito—RB23, 22 º13'47,6"S 42º08'04,7"W, 803m, 03-IV-2009, B.H.L. Sampaio leg. [ DZRJ Coleoptera-5619]; 9 specimens—Rio Bonito de Lumiar, Afluente do Córrego dos Borás, 22º23'17,6"S 42º21'57,6"W, 838m, 04-IV-2009, B.H.L. Sampaio leg. [ DZRJ Coleoptera-5620]; 1 specimen—Macaé de Cima, Rio das Flores—RF1, 22 º24'36,3"S 42º29'40,6"W, 971m, 30-XI-2008, N. Ferreira-Jr, G.A. Jardim, I.C. Gonçalves, B.H.L. Sampaio, V.P. Alecrim, A.P.M. Santos leg. [ DZRJ Coleoptera-5621]; 4 specimens— Macaé municipality, Sana, afluente de 2ª ordem do Rio Sana, Rancho Peito do Pombo—SA01, 22º19'17,7"S 42º10'58,0"W, 313m, 16-II-2009, B.H.L. Sampaio leg. [ DZRJ Coleoptera-5622]; 1 specimen—Sana, Rio Sana—SA07, 22º14'42,3"S 42º09'03,2"W, 567m, 18-II-2009, B.H.L. Sampaio leg. [ DZRJ Coleoptera-5623]; 13 specimens—Crubixais de Cima, Rio Crubixais—SP05, 22º11'38,1"S 42º04'26,1"W, 523m, 21-III-2009, G.A. Jardim, I.C. Gonçalves, B.H.L. Sampaio, V.P. Alecrim, G. Lefebvre leg. [ DZRJ Coleoptera-5625].

Etymology. This species is named in reference to the lack of a carina on the third elytral interval. The prefix sine means without and the suffix carina means keel.

Figures

FIGURE 1. Xenelmis sinecarina sp. nov.: a) habitus dorsal view; b) habitus ventral view; c) male genitalia, dorsal view.