Desmopachria nigrisphera, Braga, 2018

Braga, Rafael Benzi, 2018, Six new species and new records of the genus Desmopachria Babington (Coleoptera: Dytiscidae: Hyphidrini) from Brazil and redescription of D. varians Wehncke, 1877, Papéis Avulsos de Zoologia 58, pp. 1-15 : 11

Desmopachria nigrisphera sp. nov.

( Figures 6 A-K)

Diagnosis: Medium size for the genus 1.8 mm; body very rounded, shiny black with dense punctures ( Fig. 6A ). Male median lobe in dorsal view straight parallel-sided with apex rounded ( Fig. 6J ) with almost the same length than lateral lobes ( Fig. 6D ).

Description: Holotype male: total length 1.8 mm; maximum width of body 1.3 mm; elytral length 1.2 mm; maximum width of the pronotum 0.9 mm.

Colouration ( Figs. 6 A-C): Dorsal view shiny black with exception of the brown inner margin of pronotum ( Figs. 6 A-B); venter shiny black with exception of head, prosternum and legs testaceous ( Fig. 6C ).

Structure and sculpture: Body very rounded. Head with fine and shallow scarcely distributed punctures; pronotum with fine and shallow scarcely distributed punctures and course and deep punctures near base and in a line parallel the apical margin; elytral surface with fine and shallow densely distributed punctures and a line of fine and deep punctures in disc. Clypeus beaded; antennae with rounded scape, pedicel narrower and longer than others antennomeres, antennomeres 5-9 slightly expanded in apical half. Pronotum short and wide, with a lateral bead and without basal striae. Elytral suture margined. Prosternal process apically strongly forked, area between rami forming a deep pit; ventral surface of metatibia covered with short and wide spines. Ventral surface inconspicuous punctuated. Apical ventrite smooth without sutures or marks.

Male genitalia ( Figs. 6 D-K): Median lobe with almost the same length than lateral lobes ( Figs. 6 D-G). in dorsal view straight parallel sided apex rounded ( Fig. 6I ); in lateral view base bilobed and well separated of rest of median lobe, remainder of lobe straight until narrow apical quarter, apex rounded ( Fig. 6J ). Lateral lobes in dorsal view triangular shape with a dense row of setae on inner margin of apical third ( Fig. 6H ); in lateral view basal and middle straight almost rectangular, apical third narrowing and bended to inner side ( Fig. 6K ).

Intraspecific variation: Total length 1.8 mm; maximum width of body 1.1-1.2 mm; elytral length 1.3-1.4 mm; maximum width of the pronotum 0.9-1.0 mm.

Type material: Holotype male:“ Brasil, São Paulo, São José do/ Barreiro, Lajeado , Córrego da/ Floresta , Cachoeira do Paredão / 22°43’33”S, 44°37’18”W, / 1540 m, 17.xi.2012, Souto PM,/ Ferreira-Jr N, Silveira LFL &/ Gil-Azevedo LH, BOC13 [paper white label]”, “5957 [plastic blue label]” “ HTYPE [plastic red label]” ( DZRJ) . Paratypes: “ Brasil, São Paulo, São José do/ Barreiro, Lajeado, Córrego da/ Floresta, Cachoeira do Paredão/ 22°43’33”S, 44°37’18”W, / 1540 m, 17.xi.2012, Souto PM,/ Ferreira-Jr N, Silveira LFL &/ Gil-Azevedo LH, BOC 13 [paper white label]”, “5958 [plastic blue label]”, “ PTYPE [plastic red label]” (3 exs.) ( DZRJ).

Taxonomic notes: This new species belongs to the D. portmanni group sensu Miller (2001) in having the prosternal process sexually dimorphic. Although dark dorsal colouration is very common in the portmanni group,most species have small differences in tonality between the head, pronotum, elytrum and ventral surface, only D. grandnigra Braga & Ferreira-Jr., 2014 and D. nigra Zimmermann, 1923 , have a dorsal surface equally dark in all tagma. These two species both have a dorsal surface almost impuctate giving a vitreous aspect which is absent in the new species. Desmopachria bryanstoni Clark, 1862 , D. pittier Young, 1995 D. zetha Young, 1995 and D. goias Young, 1995 have male genitalia which are similar in shape to Desmopachria nigrisphera sp. nov. but the former three species are bigger in body size.

Etymology: The specific name is a combination of the Latin adjective “nigra” meaning dark and the substantive “sphere” meaning ball, referring to the colour and shape of this species.

Geographic distribution: So far known only from the São Paulo State of Brazil.

Figures

Figures. 6A-K. Desmopachria nigrisphera. (A) Dorsal View. (B) Colour pattern of Elytron. (C) Ventral view. (D-K) Male genitalia. (D) Dorsal view. (E) Ventral view. (F) Lateral view. (G) Coverslip dorsal view. (H) Lateral lobe dorsal view. (I) Median lobe dorsal view. (J) Median lobe lateral view. (K) Lateral lobe lateral view. Figs.6A-C scale bars = 1 mm, Figs.6D-K scale bars = 0.1 mm.