Laccophilini

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 : 309-310

Key to genera of the tribe Laccophilini

Several authors provided keys for Laccophilinae genera, often associated with description of new genera (e.g. Balfour-Browne 1939, Steiner 1981, Brancucci 1983a). The most recent key was provided by Pederzani (1995), including 11 genera and two subgenera as the author did not consider Agabetes Crotch, 1873 a member of Laccophilinae ( Burmeister 1990; Alarie et al. 2002), and Philaccolilus Guignot, 1937 had not yet been elevated to generic rank (Balke et al. 2000). Two years later, the reliability of the bifid metatibial spurs as a character that unequivocally defines Laccophilus was discussed ( Balke et al. 1997), after the discovery of a species from New Guinea which has simple spurs. In this vein the authors suggested that Philodytes is a junior synonym of Laccophilus , although this synonymy is not currently supported ( Miller et al. 2005; Nilsson 2015). All this, together with the new genus described here, makes it necessary to develop a new version of Pederzani’s key:

1. Metatibiae with a single apical spur. Antennal segments enlarged and flattened in male. Neotropical............ Napodytes

- Metatibiae with 2 apical spurs. Antennal segments never enlarged or flattened in male............................... 2

2. Suture between elytron and epipleuron visible dorsally (= “lateral sides bordered”: in dorsal view elytra visibly outlined by a fine border along outer lateral side)....................................................................... 3

- Suture between elytron and epipleuron not visible dorsally (= “lateral sides not bordered”: in dorsal view the elytra do not appear to be bordered)................................................................................. 5

3. Hind angles of pronotum rounded; base of pronotum projecting hindwards in a distinct angle at middle; prosternal process not extending beyond mesocoxae. Neotropical........................................ Laccodytes phalacroides -group

- Hind angles of pronotum extending posteriorly into acuminate spine; base of pronotum straight or almost so; prosternal pro- cess long, extending beyond mesocoxae................................................................... 4

4. Prosternal process three-pointed; posterolateral lobes of metatarsi very short, almost lacking; apex of elytra rounded. Afrotro- pical and Oriental........................................................................... Neptosternus

- Prosternal process single-pointed; posterolateral lobes of metatarsi longer, well developed; apex of elytra truncate. Neotropical.............................................................................. Laccodytes apalodes -group

5. Metatibial spurs bifid apically (except L. bapak Balke, Larson & Hendrich, 1997 from Papua New Guinea). Worldwide................................................................................................. Laccophilus

- Metatibial spurs simple, apically acute..................................................................... 6

6. Base of pronotum projecting hindwards in a distinct angle at middle............................................ 7

- Base of pronotum straight or almost so.................................................................... 11

7. Prosternal process laterally compressed behind procoxae...................................................... 8

- Prosternal process fairly broad behind procoxae............................................................. 9

8. Length not exceeding 5 mm; pro- and mesofemora and tibiae densely punctate; prosternal process markedly carinate. Tibet.................................................... Laccoporus (re-description and illustration in Zhao et al. 2011)

- Length exceeding 5 mm; pro- and mesofemora and tibiae never densely punctate; prosternal process slightly carinate. Africa............................................................................................. Philodytes

9. Metacoxal lines straight and fairly parallel; body short and broad, strongly narrowed caudally; prosternal process triangular behind procoxae, with acute apex. East Palearctic.............................................. Japanolaccophilus

- Metacoxal lines sinuate and strongly convergent anteriorly; body elongate, more gently narrowed caudally; prosternal process broadly triangular to cordiform behind procoxae, with apex rounded to acute.................................... 10

10. Mesotibial spurs not longer than segments 1–2 of mesotarsi combined; elytra covered by numerous, more or less impressed punctures. Oriental.......................................................................... Laccosternus

- Mesotibial spurs longer than segments 1–4 of mesotarsi combined; elytra lacking punctures, at most bearing very few, small, hardly visible punctures. Neotropical and SE Nearctic............................................... Laccomimus

11. Reticulation on elytra consisting of longitudinal or broad polygonal meshes; metacoxal lines fairly parallel. Afrotropical............................................................................................... Africophilus

- Reticulation on elytra consisting of small, transversal meshes; metacoxal lines more or less convergent anteriorly....... 12

12. Space between metacoxal lines strongly rugose-punctate; metacoxal processes with round meshes and distally bilobed. Australia....................................................................................... Australphilus

- Space between metacoxal lines somewhat smooth; metacoxal processes reticulate with transversal meshes and distally not bilobed............................................................................................. 13

13. Metacoxa with stridulatory file; posterolatral lobes of metatarsi short; ventrite 6 in females rounded apically. Afrotropical............................................................................................... Philaccolus

- Metacoxa lacking stridulatory file; posterolateral lobes of metatarsi very long; ventrite 6 in females with an apical lobe, more or less developed. Papua New Guinea............................................................ Philaccolilus