Laccophilus mahakamensis Balke, Mazzoldi & Hendrich, 1998

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 : 321

Laccophilus mahakamensis Balke, Mazzoldi & Hendrich, 1998

( Figs. 10 , 28 )

Laccophilus mahakamensis Balke, Mazzoldi & Hendrich, 1998: 74 (original description).

Type locality. Indonesia, East Kalimantan, district barong Tongkok, Juhan Asa, Aput stream in primary forest.

Material examined. 35 specimens. INDONESIA: E Kalimantan: 5 ex., ca. 50 km W of Balikpapan, PT Fajar Surya Swadaya [area], 01°13.4′S, 116°22.6′E, 66 m, 27+ 30 November 2011, coll. J. Hájek, J. Schneider & P. Votruba ( NMPC) ; 22 ex., ca. 15 km N of Balikpapan, Sungai Wain Protection Forest , 01°08.1′S, 116°49.9′’E, 35 m, 8–11 December 2011, coll. J. Hájek, J. Schneider & P. Votruba ( NMPC, ZSMG) . MALAYSIA: Sarawak: 1 female, E Bandar Sri Ammen [Sri Aman], Batang Ai National Park , 20 February 1993, coll. M.A. Jäch ( NHMW) ; 2 males, 1 female, G. [Gunung] Gading National Park , 30 May 2003, coll. J. Šťastný ( JSCL) . THAILAND: 2 males, 2 females, Surat Thani Province, Khao Sok National Park, pools on road from Park Hq to Bang Leap Nam waterfall, 26 July 1996, coll. P. Mazzoldi ( PMCB) .

Diagnosis. Small, elongate oval species (body length 3.4–3.7 mm). Elytra with subbasal testaceous band sinuous, narrower, usually well separated from elytral base ( Fig. 10 ). Apical part of median lobe in lateral view distinctly sinuous with elongate pointed tip ( Fig. 28 ).

Habitat. In East Kalimantan, Laccophilus mahakamensis was collected in remnant pools of small stream in remains of lowland primary forest; pools were usually with clay bottom and a thick layer of decaying leaves ( Fig. 38 ), some pools were very small (diameter less than 20 cm) with almost no visible water.

Distribution. The species was described and is so far only known from Indonesian East Kalimantan ( Balke et al., 1998). The Thai specimens correspond well with the type material stored in NHMW. The present new records markedly extend the distributional area of Laccophilus mahakamensis suggest the likelihood of more records from the Malay Peninsula and the Greater Sunda Islands ( Fig. 41 ).

Figures

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.

Figs. 36–39. Habitats: 36, E Kalimantan, Muara Ritan (type locality of Laccophilus kalimantanensis, new species); 37, China, Guangxi, Shiwandashan (locality of L. komareki, new species); 38, E Kalimantan, Sungai Wain (locality of L. mahakamensis); 39, Laos, Attapeu (locality of L. tonkinensis).

Figs. 40–41. Distribution of the species of the Laccophilus javanicus group