Laccomimus xikrin, Braga, Rafael Benzi & Ferreira-Jr, Nelson, 2016

Braga, Rafael Benzi & Ferreira-Jr, Nelson, 2016, Laccomimus xikrin sp. nov. and new records of other species of Laccomimus Toledo & Michat, 2015 (Coleoptera: Dytiscidae: Laccophilinae) from Brazil, Zootaxa 4154 (1), pp. 96-100 : 97-99

Laccomimus xikrin sp. nov.

( Figs 1–10 )

Type locality. Brazil, Pará State, Parauapebas Municipality.

Type-material. Holotype (male): ( DZRJ 5922 ) “ Brasil, PA, Parauapebas, Flona Carajás, N 1-B, novembro/ 2012, 06°1'40.78"S 50°17'30.51"W, Ferreira-Jr, N. leg.”, “ Laccomimus xikrin Braga e Ferreira-Jr.”, “Htipo” [red plastic label], “5922” [red plastic label] . Paratype: 1 ♂, ( DZRJ 5923 ) “ Brasil, Pará, Canaã dos Carajás, Flona Carajás, S 11A-D abril/2013, 06°20'31.07"S 50°25'13.67"W, Ferreira-Jr, N. leg.”, “ Laccomimus xikrin Braga e Ferreira-Jr.”, “ Ptipo ” [red plastic label], “5923” [green plastic label].

Diagnosis. Total length 2.1 mm. Elytron variegate, colored with brown and testaceous. Venter testaceous. Prosternal process short and broad; lobes of the metacoxal process spiniform in both sexes; male anterior claws unmodified. Aedeagus with median lobe slightly arched, narrowing toward the apex, lacking expansion at apex or apical fourth.

Description. Holotype. Habitus ( Fig. 1 ). Total length 2.1 mm; maximum width 1.2 mm; length between clypeus and posterior margin of eyes 0.2 mm; minimum width between eyes 0.4 mm; pronotal length 0.3 mm; elytral length 1.6 mm; maximum width of pronotum 1.0 mm. Body drop-shaped, tip of elytron rounded. Hind angle of pronotum rounded.

Colour ( Figs 1–2 ). Head testaceous, dark areas in angles posterior to eyes. Pronotum testaceous. Elytron variegate, stained of brown in middle and testaceous in lateral margin ( Fig. 2 ). Venter testaceous.

Structures and sculpture ( Figs 3–6 ). Head smooth, shiny, with fine and microreticulation that is difficult to detect. Pronotum smooth, with few shallow and fine punctures along inner and anterior margins; lateral bead narrow, posterior angle rounded, base margin medially produced posteriorly; prosternal process emarginate, apex arrow-shaped with rounded tip ( Fig. 4 ); epipleuron broad up to level of last abdominal ventrite; anterior claws subequal ( Fig. 3 ); hind lobes of metacoxal processes expanded, posterior margin with spiniform process and with slight medial incision ( Fig. 5 ); pro- and mesotarsi distinctly dilated; metatibia and metafemur similar in length; metatarsomeres 1–4 with apicolateral angle distinctly lobed. Elytral surface shiny and iridescent; microreticulation fine, poorly impressed; small, shallow, irregular grooves visible together with fine scattered punctures and a line of fine punctures following the elytral suture. Last abdominal ventrite tectiform, hind margin truncate with medial projection ( Fig. 6 ). Ventral side shiny, smooth with scattered shallow and fine punctures.

Male genitalia ( Figs 7–10 ). Median lobe elongate and asymmetrical, warped with sclerotized left side and membranous right side; in lateral view slightly arched and narrowing to rounded apex ( Fig. 9 ); in dorsal view left margin rounded and right margin almost straight, with apex rounded, slightly expanded to right side ( Fig. 8 ). Parameres asymmetrical, right paramere almost one fourth the size of left; right paramere thin, subtriangular, with one apical seta ( Fig. 10 ); left paramere elongate, with basal half subtriangular and apical half narrow and elongate, slightly arched and bearing a subapical seta ( Fig. 7 ).

Etymology. The species name is a homage to the Xikrin , the indigenous people present in the area of the Flona Carajás. It is a noun in the nominative singular standing in apposition.

Intraspecific variation. The paratype is very similar to the holotype, with slight differences in size: total length 2.1 mm; maximum width 1.3 mm; length between clypeus and posterior margin of eyes 0.2 mm; minimum width between eyes 0.4 mm; pronotal length 0.3 mm; elytral length 1.7 mm; maximum width of pronotum 1.0 mm.

Taxonomic notes. This species has a variegated coloration pattern, tending to coalesce into a lateral band, which is only comparable with L. variegatus . Laccomimus xikrin sp. nov. also shares the short and broad prosternal process and the spiniform lobe of the metacoxal process with L. amazonas , L. spinosus and L. variegatus . Laccomimus xikrin sp. nov. can be distinguished from L. variegatus by the light ventral coloration and by the medium lobe not expanded in the apical fourth. The male genitalia of L. xikrin sp. nov. are very similar to those of L. spinosus , but the latter (known only from a single male from Mato Grosso, Brazil) has uniformly brown elytra and scimitar-shaped male outer fore claws.

Distribution. Only known from Pará State, Brazil.

Figures

FIGURES 1 – 10. Laccomimus xikrin. 1. Dorsal habitus; 2. Elytral coloration pattern; 3. Male right protarsal claws, lateral aspect; 4. Prosternal process, ventral aspect; 5. Metacoxal processes, ventral aspect; 6. Male last abdominal ventrite, ventral aspect; 7. Left paramere, lateral aspect; 8. Median lobe, dorsal aspect; 9. Median lobe, lateral aspect; 10. Right paramere, lateral aspect (setae detached in holotype). Scales: Figs 1 – 6: 1.0 mm; Figs 7 – 10: 0.1 mm.