Tetrasticta gnatha sp. n., collected under the bark of a rotten fallen tree in Peninsular Malaysia, is described. A habitus photograph, line drawings of diagnostic characters, and a diagnosis are provided. The new species is readily distinguished from all known congeners by having long mandibles, and long, curved maxillary palpi.
Two new genera and two new species of Aleocharinae (Staphylinidae) from Malaysia are described: Parawroughtonilla Maruyama, gen. n. (type species: Parawroughtonilla hirsutaMaruyama, sp. n.), Leptogenonia Maruyama, gen. n. (type species: Leptogenonia roslii Maruyama, sp. n.), which are associated with Leptogenys borneensis Wheeler, 1919. They are closely related and share a unique character state of the aedeagus.
Three myrmecophilous genera of Aleocharinae (Staphylinidae) associated with Leptogenys distinguenda (Emery, 1887) and Leptogenys mutabilis (Smith, 1861) are reviewed with descriptions of new taxa: Maschwitzia Kistner, 1989, Togpelenys Kistner, 1989 and Witteia Maruyama & von Beeren, gen. n. (type species: Witteia dentilabrumMaruyama & von Beeren, sp. n.). The following new combinations are proposed: Zyras (s. lat.) aenictophila (Kistner, 1997),comb. n. (exMaschwitzia), Zyras (s. lat.) dichthadiaphila (Kistner in Kistner et al., 2003), comb. n. (exMaschwitzia), Maschwitzia derougemonti (Pace, 1984), comb. n. (exWroughtonilla Wasmann, 1899), Maschwitzia watanabei (Maruyama, 2004), comb. n. (exWroughtonilla), Maschwitzia dilatata (Pace, 2005), comb. n. (exWroughtonilla), Witteia borneensis (Pace, 1986), comb. n. (ex Wroughtonilla). These genera belong to the Wroughtonilla genus group of the tribe Lomechusini.
Cheleionwatanabeisp. n. is described from Pahang, Peninsular Malaysia and represents the third species of the genus Cheleion Vårdal & Forshage, 2010 (Coleoptera, Scarabaeidae, Aphodiinae, Stereomerini). A description of the previously unknown male of C.jendeki Král & Hájek, 2015, and a key to the species of the genus Cheleion are also provided.
Megasybacodes brevitarsis Kakizoe, Maruyama Masumoto, a new genus and new species of the tribe Rhyparini, is described based on a single female from Borneo. It is allied to the genus Sybacodes Fairmaire, 1896, but easily distinguished by its short protarsi, broad flattened basal tarsomeres of the meso- and metatarsi, broad flattened tibiae, and wrinkled pronotal and elytral surfaces. Checklist of rhyparine species from Borneo is also provided.
The genus Pseudoligota Cameron, 1920 is discovered in Japan for the first time, resulting in two taxonomic changes: a new combination P. antennata (Bernhauer, 1907), comb. nov., and a new species P. nozakii Hashizume, Yamamoto & Maruyama, sp. nov. from Okinawa Prefecture, southwestern Japan. The former species has long been placed in the genus Oligota Mannerheim, 1830. This is the fourth genus in the subtribe Gyrophaenina known from Japan. The species P. affinis Cameron, 1939 from India and Peninsular Malaysia is placed as a junior synonym of P. antennata.
Coptotermocola clavicornisgen. & sp. n. and Neotermitosocius bolivianusgen. & sp. n. of the termite inquilinous tribe Termitohospitini are described from peninsular Malaysia and Bolivia, respectively. The Termitohospitini are most readily diagnosable by the distally migrated anterior tentorial pits that are no longer associated with the antennal fossae, and by the enlarged vertex which obscures the antennal fossae dorsally. Additionally, the Termitohospitini are hypothesized to share a recent common ancestor with the Masuriini and Myllaenini due to shared derived morphologies of the lacinia distal teeth with lateral cuticular processes, presence of a unique maxillary palpomere III sensilla, and anterolateral angles of mentum produced. Habitus photographs and illustrations of diagnostic features are provided for the two new genera in order to facilitate future work.
Anew hydrophilid genus Chimaerocyon gen. nov. containing two species, C. shimadai sp. nov. (Malaysia: Pahang) and C. sumatranus sp. nov. (Indonesia: Sumatra), is described. Specimens of C. shimadai were collected from brood cells in anest of Pheidole singaporensis Özdikmen, 2010. The biology of C. sumatranus remains unknown. A molecular phylogeny based on four genes (cox1, cox2, 18S and 28S) supports the placement of the genus as deeply nested within the Cercyon-group of the tribe Megasternini. This position is supported by the subdistal position of the median spur in the hind wing (unique to Megasternini) and the presence of sucking disc on male maxilla (unique for Megastemini+Sphaeridiini). The remaining external morphology differs substantially from other representatives of Megasternini. The hypothesis that the aberrant morphology of Chimaerocyon gen. nov. is a consequence of myrmecophily is discussed.
Pycnotarsobrentus inuiae Maruyama & Bartolozzi, gen. nov. and sp. nov. (Brentinae: Eremoxenini) is described from the Lambir Hills National Park, Borneo (Sarawak, Malaysia) based on specimens collected from Crematogaster difformis F. Smith, 1857 ant nests in the myrmecophytic epiphytic ferns Platycerium crustacea Copel. and Lecanopteris ridleyi H. Christ. A second species of Pycnotarsobrentus is known from Malaysia but is represented by only one female and consequently not yet described pending discovery of a male. Pycnotarsobrentus belongs to the tribe Eremoxenini and shares some character states with the African genus Pericordus Kolbe, 1883. No species of Eremoxenini with similar morphological modifications are known from the Oriental region.