Laccomimus

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 : 326

Key to species of Laccomimus

1. Prosternal process, in lateral view, saddle-shaped, placed below (if ventral side is turned upside) metaventrite level ( Figs 24– 27 ); prosternum protruding anteriorly ( Figs 24–27 ); lobes of metacoxal processes ending in long, acuminate spine in both sexes ( Fig. 38 )........................................................................................ 2

- Prosternal process, in lateral view, straight or almost so, on same level as metaventrite ( Figs 20–22 ; 29–31); prosternum not protruding anteriorly ( Figs 20–22 ; 29–31); lobes of metacoxal processes rounded or at most angulated ( Figs 37 ; 39–40), otherwise ending in spine only in males and angulated in females ( Figs 32–36 )........................................ 4

2. Elytra variegate, with irregular patterns arranged on whole surface ( Fig. 61 ); aedeagus as in Fig. 86 .......... L. variegatus

- Elytral colouration different............................................................................. 3

3. Elytra uniformly brownish; median lobe of aedeagus not expanded apically and left paramere strongly narrowed in apical half ( Fig. 87 ); stalked suction palettes on pro- and mesotarsi normally developed.............................. L. spinosus

- Elytra dark-brown, with distinct subbasal, lateral, and subapical yellow bands as in Fig. 62 ; median lobe of aedeagus with flat leaf-like apical expansion and left paramere broad, gradually narrowed at tip ( Fig. 88 ); stalked suction palettes on pro- and mesotarsi very broad ( Figs 47–48 )............................................................... L. amazonas

4. Males: lobes of metacoxal processes ending in acuminate spine ( Fig. 32 ); both protarsal claws simple, equal in shape. Females: lobes of metacoxal processes more or less acute, but not ending in spine (with some extremely rare exceptions) ( Figs 33–36 ); gonocoxal blades two-toothed and ramus with teeth spaced and moderate in size ( Fig. 116 )................... L. distinctus

- Lobes of metacoxal processes rounded or at most obtusely angulated in both sexes; outer protarsal claw of males scimitarshaped, different from simple inner claw.................................................................. 5

5. Females with two-toothed gonocoxal blades and ramus with fine and serrate teeth ( Fig. 117 ); males with long and stiff median lobe, ending in very small, button-like expansion and left paramere distinctly bisinuate along dorsal side ( Fig. 85 )...................................................................................................... L. malkini

- Females with one-toothed gonocoxal blades and ramus with large and spaced teeth ( Figs 118 ; 120); males with apical expansion of median lobe well developed and left paramere at most with one sinuation along dorsal side...................... 6

6. Median lobe of aedeagus straight, almost lacking distinction between base and distal portion, gradually narrowed to apex, ending in wide and flat expansion ( Figs 90 ; 105–106); lobes of metacoxal processes ending in obtuse but clear angulation ( Fig. 41 )................................................................................................... 7

- Median lobe of aedeagus with base and distal portion visibly distinct, together forming an angle or a curve, apex ending in small expansion ( Figs 89 ; 91–104); lobes of metacoxal processes rounded or very poorly angulated ( Figs 39–40 )......... 8

7. Aedeagus ( Fig. 90 ): median lobe distally steam-like, with very wide apex, broadly rounded only on dorsal side; left paramere quite blunt, rounded apically..................................................................... L. youngi

- Aedeagus ( Figs 105–106 ): median lobe distally narrowed but not steam-like, apex somewhat narrower, broadly rounded on both sides or only on ventral side; left paramere slender, with more acute apex............................. L. bolivari

8. Underside at least in part black or dark brown; apical expansion of median lobe of aedeagus typically bird head-like shaped ( Fig. 103 ).................................................................................... L. bordoni

- Underside always uniformly reddish or testaceous; apical expansion of median lobe of aedeagus rounded............... 9

9. Apex of prosternal process acuminate or acutely rounded ( Figs 67–68 ); species known from Florida to Costa Rica........ 10

- Apex of prosternal process clearly rounded ( Fig. 69 ); species known from Panamá to Argentina....................... 11

10. Size smaller (TL: 1.80 –2.10 mm); distal portion of median lobe of aedeagus straight, with dorsal and ventral sides almost parallel ( Fig. 104 ).............................................................................. L. spangleri

- Size larger (TL: 2.10–2.35 mm); distal portion of median lobe of aedeagus visibly sinuate on both sides, especially ventral one ( Figs 91–93 )................................................................................. L. pumilio

11. Distal portion of median lobe of aedeagus with both sides sinuate, especially ventral one; apex ending in button-like, almost bulbous expansion ( Figs 94–102 )................................................................ L. alvarengi

- Distal portion of median lobe of aedeagus with both sides almost straight, regularly converging to apex, which ends in a wider, laterally flattened expansion ( Fig. 89 )........................................................... L. improvidus

Figures

FIGURES 20 – 25. SEMs of head, prosternum and prosternal process in Laccomimus species: 20) L. distinctus (male), ventral view, 21) idem, at higher magnification; 22) idem, oblique lateral view; 23) L. malkini (female) ventral view; 24) L. amazonas (male), ventral view (arrow indicates protruding prosternum); 25) idem, at higher magnification.

FIGURES 26 – 31. SEMs of head, prosternum and prosternal process in Laccomimus species: 26) L. amazonas (male), oblique lateral view; 27) idem, at higher magnification; 28) L. alvarengi (female) ventral view; 29) L. bordoni (female), ventral view; 30) idem, oblique lateral view; 31) idem, at higher magnification.

FIGURES 38 – 43. SEMs of Laccomimus species, ventral view. 38 – 41) metacoxal processes: 38) L. amazonas (male); 39) L. alvarengi (female); 40) L. bordoni (female); 41) L. bolivari (female); 42 – 43) abdomen on L. bordoni, showing sexual difference in last ventrite: 42) male (arrow indicates slightly sinuate caudal margins); 43) female.

FIGURES 32 – 37. SEMs of metacoxal processes in Laccomimus species, ventral view: 32) L. distinctus (male); 33 – 36) L. distinctus (females), variability in development of apical angulation in different specimens; 37) L. malkini (female).

FIGURES 59 – 66. Subschematic body shape and colour patterns in Laccomimus species: 59) L. distinctus; 60) L. malkini, a) typical specimen from Colombia, b) specimen from Piracicaba, Brazil; 61) L. variegatus (Perú); 62) L. amazonas; 63) L. pumilio (Florida, USA); 64) L. alvarengi, a – b) variation in colouration patterns; 65) L. bordoni; 66) L. spangleri.

FIGURES 84 – 87. Male genitalia in Laccomimus species, left lateral view: 84) L. distinctus, a) median lobe, b) left paramere, c) right paramere; 85) L. malkini (Loreto, Perú), a) median lobe, b) magnification of apex of median lobe, c) left paramere, d) right paramere, e) magnification of apex of median lobe (specimen from Piracicaba, Brazil); 86) L. variegatus, a) median lobe, b) left paramere, c) right paramere; 87) L. spinosus, a) median lobe, b) left paramere.

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 44 – 51. SEMs of left protarsus in Laccomimus species (males): 44) L. distinctus, general view; 45) idem, detail at higher magnification of last protarsal segment and claws; 46) idem, detail at higher magnification of stalked suction palettes; 47) L. amazonas, general view; 48) idem, detail at higher magnification of stalked suction palettes; 49) L. bordoni, general view; 50) idem, detail at higher magnification of last protarsal segment and claws; 51) idem, detail at higher magnification of stalked suction palettes.

FIGURES 116 – 121. Female genitalia and cladogram. 116 – 120) Female genitalia in Laccomimus species, left lateral view: 116) L. distinctus (Paraguay), a) left gonocoxa, b) ramus; 117) L. malkini (Perú), a) left gonocoxa, b) ramus; 118) L. alvarengi (Brazil), a) left gonocoxa, b) ramus; 119) L. variegatus (Perú), a) left gonocoxa, b) ramus; 120) L. bordoni (Bolivia), ramus (arrow indicates lateral proximal process of ramus). 121) Single most parsimonious cladogram rooted between ingroup and outgroup, with character changes mapped for each clade. Solid rectangles indicate unique character state transformations; open rectangles indicate homoplasious character state transformations. Support values are indicated on each branch as Bremer / Bootstrap.

FIGURES 103 – 106. Male genitalia in Laccomimus species, left lateral view: 103) L. bordoni, a) median lobe, b) magnification of apex of median lobe, c) left paramere, showing apex in different positions, d) right paramere; 104) L. spangleri, a) median lobe, b) left paramere; c) right paramere; 105) L. bolivari (holotype), a) median lobe, b) magnification of apex of median lobe, c) left paramere, d) right paramere; 106) L. bolivari (Suriname), a) median lobe, b) magnification of apex of median lobe.

FIGURES 67 – 83. Prosternal process and claws in Laccomimus species. 67 – 69) P rosternal process: 67) L. pumilio (Florida, USA); 68) L. pumilio (Cuba); 69) L. alvarengi (Perú). 70 – 83) M ale left protarsal claws: 70) L. bordoni (Paraguay); 71) L. malkini (Madre de Dios, Perú); 72) L. spangleri (holotype); 73) L. distinctus (holotype); 74) L. bolivari (Trinidad); 75) L. amazonas (holotype); 76) L. variegatus (Colonia Calleria, Perú); 77) L. alvarengi (holotype); 78) L. alvarengi (Loreto, Perú); 79) L. alvarengi (Guayaramerin, Bolivia); 80) L. alvarengi (Esmeraldas, Ecuador); 81) L. alvarengi (Albrook, Panamá); 82) L. pumilio (Cayo District, Belize); 83) L. pumilio (Cayamas, Cuba).

FIGURES 91 – 93. Male genitalia in Laccomimus pumilio from different localities, left lateral view: 91) Belize, a) median lobe (showing also the three general parts of median lobe), b) magnification of apex of median lobe, c) left paramere, d) right paramere; 92) Florida, USA, a) median lobe, b) magnification of apex of median lobe, c) left paramere, d) right paramere; 93) Cayamas, Cuba, a) median lobe, b) magnification of apex of median lobe, c) left paramere, d) right paramere.

FIGURES 94 – 97. Male genitalia in Laccomimus alvarengi from different localities, left lateral view: 94) holotype, a) median lobe, b) magnification of apex of median lobe, c) left paramere; 95) likely aberrant specimen from type locality, a) median lobe, b) magnification of apex of median lobe, c) left paramere; 96) Loreto, Perú, a) median lobe, b) magnification of apex of median lobe, c) left paramere, d) right paramere; 97) Mbrucuyá National Park, Argentina, a) median lobe, b) left paramere.

FIGURES 98 – 102. Male genitalia in Laccomimus alvarengi from different localities, left lateral view: 98) Mbrucuyá National Park, Argentina, a) median lobe, b) left paramere; 99) Beni, Bolivia, a) median lobe, b) magnification of apex of median lobe; 100) Santa Rosa, Bolivia, median lobe; 101) Esmeraldas, Ecuador, a) median lobe, b) left paramere; 102) Albrook, Panamá, a) median lobe, b) magnification of apex of median lobe, c) left paramere.