Laccomimus youngi, Toledo, Mario & Michat, Mariano C., 2015

Toledo, Mario & Michat, Mariano C., 2015, Description of Laccomimus gen. n. and eleven new species from the Neotropical region (Coleoptera, Dytiscidae, Laccophilinae), Zootaxa 3990 (3), pp. 301-354 : 324-325

Laccomimus youngi sp. n.

( Fig. 90 ; 127)

Type locality. Brazil, Mato Grosso, Jacaré, Parque Nacional Xingu.

Type material. Holotype male ( USNM): dissected by us; median lobe of aedeagus and parameres included in DMHF on plastic label pinned under the holotype “ Brazil, MG [= Mato Grosso], Jacare, PNX [= Parque Nacional Xingu], XI.1965, Alvarenga” [rectangular, white, handwritten], “ HOLOTYPE Laccomimus youngi Toledo & Michat” [red, rectangular, printed label].

Paratypes (7 exs, all bearing red, printed label “ PARATYPE Laccomimus youngi Toledo & Michat”): Brazil: same data as holotype (7 exs USNM: most of them unlabelled: printed label added by the present authors).

Diagnosis. Very close to L. bolivari but a bit shorter and with less clearly defined markings on elytra. Aedeagus similar to that of L. bolivari but longer, with apex ending in distinctive expansion, resembling an axe ( Fig. 90 a).

Description. TL: 2.0– 2.3 mm; MW: 1.0– 1.2 mm (holotype: TL: 2.3 mm; MW: 1.15 mm); A-TL: 2.0 mm; A- MW: 1.1 mm (NUM: 7 exs); body drop-shaped, short, regularly tapering to apex, pale markings poorly defined.

Colour (based on old specimens: colouration might be altered). Head and elytra reddish-brown; pronotum paler, with more or less defined dark elongate marking along hind margin. Elytra with poorly defined pale subbasal band–normally not fragmented–and subapical lateral area. Whole underside testaceous or pale-brown. Antennae and mouthparts testaceous. Legs testaceous except for slightly darkened metatarsi.

Structures and sculpture. Head and pronotum as in preceding species: iridescence lacking or faint on pronotum. Elytra with hardly visible subapical sinuation, gently narrowed at tip; smooth with quite impressed reticulation and shallow grooves on basal half; iridescence faint. Iridescence on underside missing or almost so. Prosternal and metacoxal processes as in preceding species.

Male. Last abdominal ventrite tectiform, with antero-lateral sides visibly sinuate. Outer claw of forelegs scimitar-shaped. Median lobe of aedeagus, in left lateral view ( Fig. 90 a), straight as in L. bolivari but longer, with more elongate, narrow, almost stem-like apex, ending in distinctive expansion, widely rounded dorsally, short and acute ventrally, resembling an axe. In dorsal view as in L. bolivari but more slender. Left paramere straight as in L. bolivari but blunt, less acute apically, very short in other dissected specimens ( Fig. 90 d, e).

Female. Last abdominal ventrite triangular, very narrowly rounded at apex, almost pointed. Genital pieces as in preceding species.

Distribution. Brazil, Mato Grosso ( Fig. 127 ). Known only from the type locality.

Etymology. Species dedicated to Prof. Frank N. Young. The specific epithet is a noun in the genitive case.

Remarks. L. youngi is very close to L. bolivari , from which it can be distinguished only by minor aedeagal differences.

Figures

FIGURES 88 – 90. Male genitalia in Laccomimus species, left lateral view: 88) L. amazonas, a) median lobe, b) left paramere, c) right paramere; 89) L. improvidus, a) median lobe, b) magnification of apex of median lobe, c) left paramere; 90) L. youngi, a) median lobe (holotype), b) magnification of apex of median lobe (holotype), c) magnification of apex of median lobe (different specimen from type locality), d) left paramere (holotype), e) left paramere (different specimen from type locality).

FIGURES 126 – 129. Distribution maps of Laccomimus species: 126) L. bordoni in South America; 127) L. bolivari (full circles), L. youngi (single open square in Brazil); 128) L. pumilio (open circles), L. alvarengi in Central America (single triangle in Panamá), L. spangleri (stars), L. bordoni in Central America (asterisks); 129) L. improvidus.