Laccodytes apalodes Guignot, 1955

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 : 43

Laccodytes apalodes Guignot, 1955

Figs (4, 7, 9, 12, 15, 22–24, 28, 44, 54, 62)

Laccodytes apalodes Guignot (1955: 8) (original description); Nilsson (2001: 239) (catalogue).

Type locality. French Guyana: Cayenne area.

Type material. Holotype Ƥ ( MNHN, Guignot collection): Guyane Fr. [française], Env. [environs], VIII 1937 // Museum Paris, Coll. Guignot // Laccodytes apalodes . The holotype was studied and illustrated by Paul Spangler in 1980, and the redescription of L. apalodes is based on the notes taken by Paul Spangler back then, as well as on USNM specimens which agree well with these notes on the holotype.

Other material studied. Guyana: Mazaruni-Potaro Distr., Takutu Mts., Takutu lumber camp, 6°15'N 59°00'W, 30.XII.1982, W.E. Steiner, J.E. Lowry & G.W. Williams (6 exs USNM); Takutu Mts., 6°15'N 59°5'W, Earthwatch research expedition, 3.–19.XII.1983, P.J. Spangler, W.E. Steiner & R.A. Faitoute (59 exs CMT, USNM, ZSM, NMW).

Suriname: Carolina Creek , 10 km from Zanderij, waterhole in forest st., 18.XI.1962, B. Malkin (2 exs USNM).

Venezuela: TF Amazonas, Cerro de la Neblina, basecamp, 140 m, 0°50'N 66°09'W, 24.XI.–1.XII.1984, R.L. Brown (1 ex. USNM); Cerro de la Neblina, basecamp, 140 m, 0°50'N 66°10'W, 19.II.1985, P.J. Spangler, & A.R. Faitoute (2 exs USNM); Amazonas state, 5°03.707'N 67°46.768'W, 92 m, river near Orinoco/Sipapo confluent, 15.I.2009, shallow backwaters, A. Short (locality number VZ09-0115-01C) (1 ex. KUL); Bolivar state, 6.58694°N 67.0912°W, Rio Caripito, near Rio Orinoco, 12.I.2009, A. Short & K.B. Miller (locality number VZ09-0112-02°) (12 exs KUL).

Diagnosis. Habitus ( Fig. 28 ). Body length 1.7–1.8 mm. Body slightly drop-shaped, tip of elytron truncate. Hind angle of pronotum produced backwards, acute and needle-shaped.

Color. Head and pronotum yellow; base of pronotum usually with a thin dark band. Elytron blackish with contrasting yellow marks: a subbasal transverse band; a small patch on the sutural angle; and an apical mark which is expanded forwards along the margin to the middle of the elytron. The subbasal band reaches the margin and the anterior angle of elytron. Sometimes, the subbasal band and the apical patch fuse marginally in the middle of elytron ( Fig. 28 ). Appendages of body and venter yellowish to ferruginous.

Sculpture. The entire surface of the beetle apparently with a faint MR or shagreenation (40x). Few punctures visible on head and metaventrite, more densely punctate on elytron ( Fig. 22 ). No longitudinal lines or longish meshes visible. Metacoxal shagreenation consisting of network of impressed lines densely packed with what appear to be tiny sensillae ( Figs 23, 24 )

Structures. Pronotum with narrow lateral bead; posterior angles produced backwards, needle-shaped, acute. Prosternum and base of prosternal process with small ridge; prosternal process broadly carinate and with a long, needle-like, acute tip. Epipleuron broad up to level of sternite 6 or 7. Metatarsomeres 1–4 with apicolateral angle distinctly lobed ( Fig. 12 ). Hind lobes of metacoxal process rather straight, with a deep Vshaped medial incision ( Fig. 9 ).

Male. Pro- and mesotarsi slightly dilated. Hind margin of sternite 7 rounded ( Fig. 54 ). Aedeagus ( Fig. 44 ): median lobe elongate, narrowed at tip, broadened in the middle from which a membranous expansion emerges. Parameres of different size, both with a long apical seta: the right larger and subtriangular, the left elongate and twisted near the base.

Female. Hind margin of sternite 7 protruding medially, ending with a deep U- or V-shaped emargination ( Fig. 54 ).

Distribution ( Fig. 62). French Guyana, Guyana, Suriname, Venezuela.

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

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 17 – 25. SEMs of MR in some Laccodytes species: 17) detail of elytron of L. americanus (magn. 2100 x); 18) idem, (magn. 2600 x); 19) metacoxa (MTX) and metaventrite (MTS) of L. americanus; 20) idem, detail at higher magnification; 21) idem, detail of metaventrite (MTX) at higher magnification; 22) detail of elytron of L. apalodes; 23) detail of metacoxa of L. apalodes; 24) idem, detail at higher magnification; 25) detail of metacoxa of L. neblinae.

FIGURES 3 – 16. SEMs of some Laccodytes species structures: 3) segments 1 - 3 in male protarsus of L. americanus; 4) prosternal process of L. apalodes; 5) idem, L. americanus; 6) idem, L. neblinae; 7) metaventrite of L. apalodes, the arrow indicates the groove in which the tip of prosternal process fits; 8) idem, L. neblinae; 9) metacoxal process of L. apalodes; 10) idem, L. americanus; 11) idem, L. neblinae; 12) hind tarsus of L. apalodes (male); 13) idem, L. americanus (male); 14) idem, L. neblinae (female); 15) ovipositor of L. apalodes; 16) idem, L. americanus.

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 44 – 47. Male genitals in Laccodytes species: 44) L. apalodes: a) median lobe of aedeagus in lateral view, b – c) right and left parameres; 45) L. rondonia: idem; 46) L. americanus: idem; 47) L. phalacroides: a) apical half of median lobe of aedeagus in dorsal view, b) median lobe in lateral view, c – d) right and left parameres;