A taxonomic review of the Oriental Laccophilus javanicus species group (Coleoptera: Dytiscidae) Author Hájek, Jiří Department of Entomology, National Museum, Cirkusová 1740, CZ- 193 00 Praha 9 – Horní Počernice, Czech Republic jiri_hajek@nm.cz Author Brancucci, Michel Naturhistorisches Museum, Basel, Switzerland text Raffles Bulletin of Zoology 2015 2015-08-06 63 309 326 journal article 55750 10.5281/zenodo.5385198 c7f95b94-53f8-420d-97c5-4e27d7c211bf 2345-7600 5385198 AC7F1491-CD89-4F10-9D61-55354B55E368 Laccophilus jaechi , new species ( Figs. 7 , 24 ) Type locality. Thailand , Trat Province , Ko Chang Island . Material examined. Holotype male, labelled: O [eastern] – THAILAND 1990 / Ko Chang [Island] (12) / White Sands Beach / leg. Jäch 10.12. ( NHMW ) . Paratypes : 1 male , 2 females : same label data as holotype ( NMPC , NHMW ) ; 1 male : Khao Sebap / THAILANDE / XI. 1981 / Coll. T. Lander ( NHMB ); 4 males , 4 females : CAMBODIA SW, 20kmSE / KOH KONG : Tatai riv. / 11°34′, N103°07′E / 3.-19.v.2005 , 50- 300 m , / E.Jendek & O.Šauša leg. ( NHMB , NMPC ). Diagnosis. Medium sized, oval oblong species (body length 4.1–4.4 mm ). It is very similar to L. tonkinensis in habitus and elytral colouration, and to L. hendrichi and L. javanicus in general shape of penis. The new species differs from all three mentioned species by the distinct shape of the median lobe distal part, which is ventrally very weakly sinuate, apically with small inflexed point. Laccophilus jaechi differs from L. hendrichi and L. javanicus also in the constant very broad testaceous elytral subbasal band not separated from the elytral base. Description. Colouration: Head and pronotum testaceous, elytra brownish-black with testaceous pattern consisting of broad sinuous subbasal transverse band not separated from base of elytra, indistinct latero-medial spot, narrow preapical transverse band interrupted on suture, and a small indistinct apical spot ( Fig. 7 ). Appendages and ventral part testaceous. Surface structures and sculpture: Head reticulation simple, composed of large irregular polygonal meshes, which are moderately deeply impressed. Frons between eyes, and clypeus with several large punctures. Reticulation of pronotum same as that of head. Pronotum along fore and basal margins and in posterior angles with numerous large setigerous punctures. Reticulation of elytra simple, composed of large irregular polygonal meshes similar to that of head or pronotum, but slightly more impressed. Meshes mostly complete, inner space often with several (1–3) small punctures. Each elytron with indistinct, sutural, discal and lateral row of large serial setigerous punctures. Ventral part reticulated with fine elongated meshes. Prosternal apophysis lanceolate. Abdominal ventrites with numerous oblique grooves and several large setigerous punctures, lateral margin bordered. Apical ventrite rounded posteriorly, with large setigerous punctures and transverse grooves on disc. Male pro- and mesotarsomeres 1–3 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. 24 . Female genitalia: Similar to male; pro- and mesotarsomeres not dilated. Variability. Specimens of the type series vary in extent of elytral colour pattern, especially of the subbasal testaceous band, the major part of which is separated in some specimens from the elytral base. Measurements (N= 13). Body length 4.1–4.4 mm (mean value = 4.3 mm , holotype 4.1 mm ); width 2.3–2.5 mm (mean value = 2.4 mm , holotype 2.3 mm ). Etymology. The new species is dedicated to its collector, our colleague Manfred A. Jäch (NHMW), a specialist on Hydraenidae and Dryopoidea. Distribution. So far known only from a small area of southeastern Thailand and south-western Cambodia ( Fig. 40 ).