Laccodytes takutuanus, Toledo, Mario, Spangler, Paul J. & Balke, Michael, 2010

Toledo, Mario, Spangler, Paul J. & Balke, Michael, 2010, Taxonomic revision of the Neotropical diving beetles genus Laccodytes Régimbart, 1895 (Coleoptera: Dytiscidae), Zootaxa 2347, pp. 37-58 : 51

Laccodytes takutuanus sp.n.

Figs (32, 40, 48, 58, 62)

Type locality. Guyana: Mazaruni-Potaro District, Takutu Mountains.

Type material. Holotype 3 ( USNM): Guyana, Mazaruni-Potaro District, Takutu Mountains, 06°15'N 59°05'W, Earthwatch research expedition, 17.–18.XII.1983, P.J. Spangler & W.E. Steiner. Paratypes: Same data as holotype (44 exs CMT, USNM, ZSM, NMW); Takutu Mountains, 6°15'N 58°55'W, 19.XII.1983, Earthwatch research expedition, P.J. Spangler & W.E. Steiner (4 exs USNM); Takutu Mountains, 06°15'N 59°05'W, 3.–10.XII.1983, Earthwatch research expedition, P.J. Spangler & W.E. Steiner (7 exs USNM); Mazaruni-Potaro District, Skull Point, 24.XII.1982, W.E. Steiner (6 exs USNM).

Venezuela: Amazonas, San Carlos de Rio Negro, 01°15’N 67°03’W 6.–12.XII.1984, R.L. Brown (1 ex. USNM).

Diagnosis. Habitus ( Fig. 32 ). Body length 1.6–1.7 mm. Body slightly drop-shaped, tip of elytron obliquely truncate, almost concave. Hind angle of pronotum rounded. Base of pronotum slightly narrower than elytral shoulders, therefore a poorly pronounced angle between pronotum and elytra visible.

Color. Head and pronotum yellow; base of pronotum black. Elytron blackish with contrasting yellow marks: a subbasal transverse band that is composed of three longitudinally oriented spots; a basal patch in the middle of elytron; a longitudinal medio-sutural patch; and a large apical mark, covering the posterior portion of elytron (refer to Fig. 32 for explanation). The elytral coloration is highly variable. The medio-sutural mark may be absent, or all the yellow patches are expanded, fusing to some degree, in which case the elytron is almost completely yellow. Body appendages yellowish. Ventral side of head, prosternum and epipleuron mainly yellow; metaventrite, metacoxa and metaoxal process mainly blackish; abdomen yellow.

Sculpture. The entire dorsal and ventral surface of the beetle with a faint MR. Few punctures on metaventrite. No longitudinal lines or longish meshes visible. A series of transverse shallow grooves is visible at about the anterior half of metacoxal plates.

Structures. Pronotum with narrow lateral bead; posterior angle rounded. Prosternum and prosternal process with small ridge; prosternal process broadly carinate and with a moderately long, needle-like, acute tip ( Fig. 40 ). Epipleuron broad up to level of sternite 6 or 7. Fore and middle legs very long and slender. Hind tarsomeres 1–4 with apicolateral angle distinctly lobed. Hind lobes of metacoxal process rounded, appearing divided only by a slight incision.

Male. Pro- and mesotarsi not dilated. Hind margin of sternite 7 rounded ( Fig. 58 ). Aedeagus ( Fig. 48 ): median lobe, in lateral view, arched, regularly tapering apically, slightly hooked on tip; in dorsal view sinuate, with tip acute and gently turned to the right. Parameres different in size but similarly shaped: both subtriangular; the right one bearing two long apical setae.

Female. Sternite 7 ( Fig. 58 ) slightly concave on both sides, hind margin with a small, shallow and wide Vshaped emargination in the middle.

Distribution ( Fig. 62). Northwestern Guyana and southwestern Venezuela.

Biology. In Guyana, the species was collected at blacklight in a forest clearing, close to a stream.

Derivatio nominis. Name derived from Takutu Mountain, type locality of this species.

Figures

FIGURES 28 – 39. Subschematic body shape and colour patterns: 28) Laccodytes apalodes; 29) L. rondonia; 30) L. americanus; 31) L. phalacroides; 32) L. takutuanus; 33 a – 33 b) L. neblinae (variation of elytral patterns); 34) L. bassignanii; 35) L. obscuratus; 36) L. olibroides; 37) L. androginus; 38) Laccodytes sp. 1.; 39) Laccodytes sp. 2.

FIGURES 40 – 43. Line drawings of prosternal process: 40) Laccodytes takutuanus; 41) L. phalacroides; 42) L. rondonia; 43) L. olibroides.

FIGURES 54 – 61. Last abdominal segment (left male; right female) in Laccodytes species: 54) L. apalodes; 55) L. rondonia; 56) L. americanus; 57) L. phalacroides; 58) L. takutuanus; 59) L. neblinae; 60) L. bassignanii; 61) Laccodytes sp. 1 female.

FIGURES 48 – 53. Male genitals in Laccodytes species: 48) L. takutuanus: a) median lobe of aedeagus in dorsal view, b) in lateral view, c-d) right and left parameres; 49) L. neblinae: a) median lobe of aedeagus in dorsal view, b) in lateral view, c-d) right and left parameres; 50) L. bassignanii: a) median lobe of aedeagus in dorsal view, b-c) in dorsal-lateral and lateral view, d-e) right and left parameres; 51) L. obscuratus: a) median lobe of aedeagus in dorsal view, b) in lateral view, c-d) right and left parameres; 52) L. olibroides: a) median lobe of aedeagus in lateral view, b-c) right an left parameres; 53) L. androginus: a) median lobe of aedeagus in dorsal view, b) in lateral view, c-d) right and left parameres.