Laccophilus javanicus, Regimbart, 1899

Hájek, Jiří & Brancucci, Michel, 2015, A taxonomic review of the Oriental Laccophilus javanicus species group (Coleoptera: Dytiscidae), Raffles Bulletin of Zoology 63, pp. 309-326 : 310-311

The Laccophilus javanicus species group was erected by Guignot (1959) for a single African species L. flavopictus Régimbart, 1889 . Although Guignot was apparently aware of Oriental species, he never listed them. Consequently, the group was adopted and modified by Brancucci (1983), who defined this species group as follows: Surface of pronotum and elytra with simple reticulation, composed entirely of large polygonal meshes. Very large species (body length 3.4–5.1 mm), of very broad and depressed shape. Elytra brown to black, with pale bands and other markings. Another characteristic of the group is: Prosternal apophysis relatively short and lanceolate; posterior margin of apical ventrite rounded in both sexes.

Brancucci (1983) assigned nine Oriental species distributed from India, through continental Southeast Asia, east to the Sunda Islands, to the L. javanicus -group. More recently, Balke et al. (1998) described a tenth species from Kalimantan. In the present work, we adopt the concept of the group from Brancucci (1983) and consider it to be exclusively Oriental; Afrotropical Laccophilus flavopictus is removed from the L. javanicus group, as it does not seems to be closely related to Oriental species (O. Biström, pers. comm.).

At present, the Laccophilus javanicus species group comprises 18 species:

Laccophilus aurofasciatus Vazirani, 1972 – India (Kerala, Tamil Nadu)

Laccophilus auropictus Régimbart, 1899 – India (Karnataka, Tamil Nadu), Myanmar (Tenasserim)

Laccophilus ceylonicus Zimmermann, 1919 – India (Maharashtra, Orissa), Sri Lanka

Laccophilus elegans Sharp, 1882 – India (Andaman and Nicobar Islands, Andhra Pradesh, Karnataka, Kerala, Nagaland, Orissa, West Bengal)

Laccophilus girardi Brancucci, 1983 – Malaysia (Sabah)

Laccophilus hendrichi , new species – Myanmar, Thailand, Laos

Laccophilus jaechi , new species – Cambodia, Thailand

Laccophilus javanicus Régimbart, 1899 – Indonesia (Java, Bali, Lombok)

Laccophilus kalimantanensis , new species – Indonesia (Kalimantan)

Laccophilus komareki , new species – China (Guangdong, Guangxi)

Laccophilus mahakamensis Balke, Mazzoldi & Hendrich, 1998 – Thailand, Malaysia ( Sarawak), Indonesia (Kalimantan)

Laccophilus mazzoldii , new species – Laos, Thailand

Laccophilus nusatenggaraensis , new species – Indonesia ( Flores, Sumba, Sumbawa, Timor)

Laccophilus schillhammeri , new species – Myanmar

Laccophilus stastnyi , new species – Malaysia ( Sarawak)

Laccophilus tobaensis Brancucci, 1983 – Indonesia (Sumatra)

Laccophilus tonkinensis Brancucci, 1983 – China (Hainan), Laos, Vietnam

Laccophilus wittmeri Brancucci, 1983 – China (Yunnan), Myanmar, Thailand, Laos, Vietnam

A key to species of the Laccophilus javanicus group (males only)

1. Smaller species (body length 3.5–4.5 mm), elongate oval ( Figs. 3–8 , 10, 12–16 ) .......................................................................2

– Large species (body length 4.5–5.0 mm), broadly oval ( Figs. 1, 2, 9 , 11, 17 ).......................................................................14

2. Small species (body length 3.4–3.8 mm); Borneo ( L. mahakamensis also known from southern Thailand).............3

– Medium sized species (body length 3.8–4.5 mm); so far unknown from Borneo ............................................................................6

3. Subbasal testaceous band very broad, covering at least basal third of elytra; or elytra almost uniformly testaceous ( Fig. 5 ) .................................................................................................4

– Subbasal testaceous band sinuous, narrower, usually well separated from elytral base ( Figs. 10, 14 )..............................5

4. Apical part of median lobe in lateral view almost straight, narrowing to apex which is bent dorsally ( Fig. 22 ); body length 3.5–3.7 mm; Sabah .................................................... L. girardi

– Apical part of median lobe in lateral view almost regularly curved to apex ( Fig. 26 ); body length 3.6–3.8 mm; Kalimantan ........ .............................................. L. kalimantanensis , new species

5. Apical part of median lobe in lateral view distinctly sinuous with elongate pointed tip ( Fig. 28 ); body length 3.4–3.7 mm; Sarawak, Kalimantan; southern Thailand..... L. mahakamensis

– Apical part of median lobe in lateral view less sinuous with shortly pointed tip ( Fig. 32 ); body length 3.5–3.6 mm; Sarawak: Bako NP ............................................. L. stastnyi , new species

6. Apical part of median lobe in lateral view with distinct bulge on dorsal side (cf. Figs. 20, 21, 30, 34 ) .................................7

– Apical part of median lobe in lateral view with dorsal side almost straight or very slightly curved (cf. Figs. 23–25, 30, 33 ) ..........................................................................................10

7. Subbasal testaceous band sinuous, narrow, well separated from elytral base ( Figs. 3 , 13 ) .........................................................8

– Subbasal testaceous band broad, more or less connected with elytral base ( Figs. 4 , 16 ) .........................................................9

8. Apical part of median lobe narrow with pointed tip ( Fig. 20 ); body length 3.8–4.1 mm; Sri Lanka, India........ L. ceylonicus

– Apical part of median lobe broad with blunt tip ( Fig. 31 ); body length 3.8–4.3 mm; Myanmar.................................................. .................................................. L. schillhammeri , new species

9. Apex of median lobe short, blunt ( Fig. 21 ); body length 3.8–4.0 mm; Andaman and Nicobar Islands, India.............. L. elegans

– Apex of median lobe elongate with pointed tip ( Fig. 34 ); body length 3.8–4.1 mm; China (Hainan), Laos, Vietnam............... ............................................................................ L. tonkinensis

10. Broadly oval species; elytral subbasal testaceous band divided longitudinally into separate spots ( Fig. 15 ); apical part of median lobe shorter, almost subparallel ( Fig. 33 ); body length 4.4–4.5 mm; Sumatra ......................................................... L. tobaensis

– Elongate oval species; elytral subbasal testaceous band complete; apical part of median lobe longer.........................................11

11. Anterior margin of elytral subbasal testaceous band almost rectilinear ( Fig. 8 ); body length 4.0– 4.4 mm; Java, Bali, Lombok.................................................................. L. javanicus

– Anterior margin of elytral subbasal testaceous band sinuous ( Fig. 6 ), or band very broad connected with elytral base ( Figs. 7 , 12 )......................................................................................12

12. Ground colour of elytra usually pale brown, thus testaceous pattern not well recognisable ( Fig. 12 ), if elytra dark, then subbasal testaceous band very broad but well separated from elytral base; body length 4.0– 4.5 mm; Flores, Sumba, Sumbawa, Timor ................................ L. nusatenggaraensis , new species

– Elytra dark, subbasal testaceous band differently shaped; continental SE Asia ..............................................................13

13. Subbasal testaceous band sinuous, narrow, well separated from elytral base ( Fig. 6 ); apex of median lobe nearly straight ( Fig. 23 ); body length 3.8–4.4 mm; Laos, Myanmar, Thailand....... ......................................................... L. hendrichi , new species

– Subbasal testaceous band broad, more or less connected with elytral base ( Fig. 7 ); apex of median lobe bent ( Fig. 24 ); body length 4.1–4.4 mm; SW Cambodia, SE Thailand.................... ............................................................... L. jaechi , new species

14. Reticulation of elytra composed of well impressed comparatively smaller sized meshes; apical part of median lobe in lateral view slightly curved on dorsal side, apex blunt ( Fig. 29 ); body length 4.6–4.7 mm; C Laos, E Thailand... L. mazzoldii , new species

– Reticulation of elytra composed of shallowly impressed very large meshes; apex of median lobe acute ( Figs. 18, 19, 27, 35 )..........................................................................................15

15. Elytra without mediolateral spot ( Figs. 1, 2 ); apical part of median lobe in lateral view with distinct bulge on dorsal side ( Figs. 18, 19 ); S India...........................................................16

– Elytra either with mediolateral spot ( Fig. 17 ), or ground colour of elytra pale ( Fig. 9 ); apical part of median lobe in lateral view with dorsal side almost straight ( Figs. 27, 35 ); continental SE Asia........................................................................................17

16. Subbasal testaceous band broad, straight, not separated from elytral base ( Fig. 1 ); body length 4.6–4.9 mm; S India.......... ........................................................................ L. aurofasciatus

– Subbasal testaceous band narrow, sinuous, well separated from elytral base ( Fig. 2 ); body length 4.5–4.7 mm; S India.......... ............................................................................. L. auropictus

17. Ground colour of elytra pale, testaceous pattern bordered with narrow black rim ( Fig. 9 ); apical part of median lobe relatively longer, with dorsal side almost straight, and long pointed apex ( Fig. 27 ); body length 4.5–4.9 mm; China (Guangdong, Guangxi) ........................................... L. komareki , new species

– Ground colour of elytra dark, brown-blackish ( Fig. 17 ); apical part of median lobe relatively shorter, with dorsal side lightly curved, and short and hooked apex ( Fig. 35 ); body length 4.5–5.1 mm China (Yunnan), Laos, Myanmar, Thailand, Vietnam..... ................................................................................. L. wittmeri

Figures

Figs. 1–9. Habitus of Laccophilus: 1, L. aurofasciatus; 2, L. auropictus; 3, L. ceylonicus; 4, L. elegans; 5, L. girardi; 6, L. hendrichi, new species; 7, L. jaechi, new species; 8, L. javanicus; 9, L. komareki, new species. Scale bar = 1 mm.

Figs. 10–17. Habitus of Laccophilus: 10, L. mahakamensis; 11, L. mazzoldii, new species; 12, L. nusatenggaraensis, new species; 13, L. schillhammeri, new species; 14, L. stastnyi, new species; 15, L. tobaensis; 16, L. tonkinensis; 17, L. wittmeri. Scale bar = 1 mm.

Figs. 18–35. Median lobe in lateral view: 18, Laccophilus aurofasciatus; 19, L. auropictus; 20, L. ceylonicus; 21, L. elegans; 22, L. girardi; 23, L. hendrichi, new species; 24, L. jaechi, new species; 25, L. javanicus; 26, L. kalimantanensis, new species; 27, L. komareki, new species. 28, L. mahakamensis; 29, L. mazzoldii, new species; 30, L. nusatenggaraensis, new species; 31, L. schillhammeri, new species; 32, L. stastnyi, new species; 33, L. tobaensis; 34, L. tonkinensis; 35, L. wittmeri. Scale bar = 0.5 mm.