Laccophilus kalimantanensis, Hájek & Brancucci, 2015

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 : 320

Laccophilus kalimantanensis , new species

( Fig. 26 )

Type locality. Indonesia, East Kalimantan, 8 km N of Muara Ritan village , 00°28.4′N, 116°02.7′E, 95 m.

Material examined. Holotype male, labelled: INDONESIA, E KALIMANTAN / ca. 8 km N of Muara Ritan vill. / 00°28.4′N, 116°02.7′E, 95 m / J. Hájek, J. Schneider & / P. Votruba leg. 6.xii.2011 // border of secondary forest / and clearing-field; individual / collecting in stream ( NMPC). Paratypes: 1 female: same label data as holotype ( NMPC) ; 1 male: same label data as holotype, and an additional label: DNA / M. Balke / 5647 [green typing] ( ZSMG) ; 1 male: Indonesia : E Kalimantan, ca. 8 / km N of Muara Ritan vill., 95m, / 6.xii.2011, 00°28.4′N / 116°02.7′E, J. Hájek, J. / Schneider & P. Votruba / (KAL-Jiri08) // DNA / M. Balke / 5648 [green typing] ( ZSMG) ; 14 males, 13 females: Central Kalimantan, 24.VII.2004 / Kahayan basin . Upstream River / Rowo Series of small ponds in / primary forest P. Mazzoldi (16) ( NHMB, NHMW, NMPC, PMCB); 7 males, 4 females: West Kalimantan, Melawi basin / upstream Sungai Embalau , small / left tributary (13) 1.I.2005 / P.Mazzoldi leg. ( PMCB) ; 1 female: West Kalimantan, Melawi / basin, Sungai Beluaq and small / tributary 29.XII.2004 (5) / P.Mazzoldi leg. ( PMCB) .

Diagnosis. Smaller, oblong oval species (body length 3.6–3.8 mm). Due to light brown body colouration with extended pale colouration of elytra, Laccophilus kalimantanensis is very similar to L. girardi , from which it can only be reliably distinguished based on the shape of the male genitalia. In the new species, the apical part of the median lobe in lateral view is almost regularly curved to apex.

Description. Colouration: Head and pronotum testaceous, elytra brown with extensive testaceous pattern consisting of broad basal band reaching nearly midlength of elytra, and broad preapical band often continuing to elytral apex (cf. Fig. 5 ). Appendages and ventral part testaceous.

Surface structures and sculpture: Head reticulation simple, composed of large irregular polygonal meshes, which are very superficially impressed. Frons between eyes, and clypeus with several large punctures. Reticulation of pronotum similar to that of head, but meshes somewhat larger. Pronotum along margins and in posterior angles with numerous large setigerous punctures. Reticulation of elytra simple, consists of large polygonal meshes similar to that of pronotum, but even more superficially impressed and barely perceptible; meshes often incomplete. Sutural row of punctures reduced to few punctures preserved mostly near base; discal and lateral rows of punctures present, but lateral discal row and lateral row barely perceptible. Ventral part reticulated with fine meshes. Prosternal apophysis short and lanceolate. Abdominal ventrites with numerous oblique grooves and several large setigerous punctures, lateral margin bordered; apical ventrite rounded posteriorly, on disc with several medium sized setigerous punctures. Male pro- and mesotarsomeres 1–3 very weakly dilated with bundle of adhesive setae on ventral side. Claws of pro- and mesotarsi simple and equal.

Male genitalia: Median lobe of aedeagus in lateral view as in Fig. 26 .

Female genitalia: Similar to male; pro- and mesotarsomeres not dilated.

Variability. The specimens of the type series vary in colouration of elytra: the ground colour of some specimens is light brown, making the testaceous pattern almost imperceptible and the elytra appear unicolourous.

Measurements (N= 20): Body length 3.6–3.8 mm (mean value 3.7 mm, holotype 3.6 mm); width 2.1–2.2 mm (mean value 2.2 mm, holotype 2.1 mm).

Etymology. The new species is named after Kalimantan Island, its area of distribution.

Habitat. At the type locality, Laccophilus kalimantanensis was collected in a shaded remnant pool of a drying up forest stream; diameter of pool ca. 1 m, clay bottom with several larger stones, without vegetation or fallen leaves ( Fig. 36 ).

Distribution. The species is confined to several localities in the central part of Kalimantan Island, Indonesia ( Fig. 40 ).

Figures

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. 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. 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