A new species of the rare genus Rutaraphes Jaloszynski from Japan (Coleoptera, Staphylinidae, Scydmaeninae).

To date, the stenichnine genus Rutaraphes Jaloszynski includes only two species: R. shikokuensis Jaloszynski (Japan) and R. taiwanicus Jaloszynski (Taiwan), both known from a single holotype male. Consequently, Rutaraphes can be placed among the rarest Palaearctic genera of Scydmaeninae. Three males of this remarkable genus were found recently during a museum survey, all collected in a flight intercept trap in Central Honshu, Japan. They represent a new species, described herein as Rutaraphes honshuensis sp. n., morphologically close to R. shikokuensis.

Percussiopalpus gen. n. from Turkey, a free-living relative of cave-dwelling Thaumastocephalus, and revised placement of Thaumastocephalini (Coleoptera: Staphylinidae: Pselaphinae).

A new genus and species, Percussiopalpus inusitatus Hlavác & Jaloszynski gen. n. et sp. n. of the tribe Thaumastocephalini is described and illustrated, based on specimens collected in the Asian part of Turkey (Balikesir Province). The discovery of a free-living pselaphine species morphologically closely resembling the obligate cavernicolous Thaumastocephalus Poggi et al. prompted a detailed morphological study of both genera, which results in transferring Thaumastocephalini from Batrisitae to Euplectitae.

New species and new records of Eastern Palaearctic Stenichnus Thomson (Coleoptera, Staphylinidae, Scydmaeninae).

Two new scydmaenine species are described based on specimens collected in Taiwan: Stenichnus (s. str.) bifurcatus sp. n., and Stenichnus (s. str.) totoroides sp. n. New records are provided for Stenichnus totoro Jaloszynski (Japan: Iriomote-jima and Ishigaki-jima), S. bellulus Jaloszynski (Taiwan; Japan: Iriomote-jima, Ishigaki-jima, and for the first time recorded from Yonaguni-jima), S. taiwanicus Franz (Taiwan), S. bicolor (Denny) (Europe, Mongolia, Siberia, Russian Far East, and for the first time recorded from Japan: Iwate Prefecture), S. dividus Kurbatov (Russian Far East; for the first time recorded from Japan: Fukushima Prefecture), S. lackneri Jaloszynski (Japan: Tokunoshima, and for the first time recorded from Amami-Ôshima and Okinawa-jima), S. pollens (Sharp) (Japan: Kyushu, and for the first time recorded from Honshu), S. minipollens Jaloszynski (Japan: Hokkaido, and for the first time recorded from Kyushu and Shikoku), and S. saltuarius Kurbatov (Russian Far East; for the first time recorded from China: Heilongjiang Province). Moreover, records of six undescribed Japanese species of Stenichnus known from females are given, to facilitate future study on the still poorly known diversity of this genus in Eastern Palaearctic. Stenichnus dividus and S. saltuarius are placed in the nominotypical subgenus.

A new species of Syndicus s. str. from Sumatra (Coleoptera, Staphylinidae, Scydmaeninae).

To date, only one species of the nominotypical subgenus of Syndicus Motschulsky was known to occur in Sumatra. A second species, Syndicus (s. str.) minimus sp. n., is described, based on males and females collected in Aceh, North and West Sumatra provinces. The new species is remarkably small-bodied and has conspicuously punctate elytra. An updated checklist of species in the nominotypical subgenus of Syndicus is given.

Discovery of Obesoconnus Jaloszynski in the Oriental Region (Coleoptera, Staphylinidae, Scydmaeninae).

To date, Obesoconnus Jaloszynski is known to occur in French Guiana, Mexico and Costa Rica. Here, two new species, O. asymmetricus sp. n. and O. pallidus sp. n., are reported to occur in Thailand. Scydmaenine genera showing a similar distribution are discussed, and since the 'Alloraphes/Stenichnodes group', to which Obesoconnus belongs, is known to occur in Neotropical, Afrotropical and Oriental regions, it is possible that in the future the genus may be discovered also in tropical Africa.

Two new species of Paraneseuthia Franz from Okinawa-jima (Coleoptera, Staphylinidae, Scydmaeninae).

Only one (recently discovered) nominal species of the eutheiine genus Paraneseuthia Franz is known to occur on the largest Ryukyuan Island of Okinawa-jima, while five other members of this rare genus inhabit Ishigaki-jima, Shikoku, Kyushu and Honshu. Undescribed species known from females only have been collected also on southwestern Iriomote-jima and northeastern Hokkaido. Two new Okinawan species are described: P. uminzo sp. n. and P. umisatu sp. n., suggesting that the diversity of Paraneseuthia in the Ryukyus is still known fragmentarily and new discoveries can be expected in other forested southern islands.

Two new species of Syndicus in southern India (Coleoptera, Staphylinidae, Scydmaeninae).

To date, five species of the Australo-Oriental genus Syndicus Motschulsky have been discovered in India, although the true distribution of one of them (the type species of the genus) remains unclear, as the only known specimen comes from "Indes orientales", a large historical area that also included territories outside the Indian subcontinent. Two new species are described: Syndicus (s. str.) microphthalmus sp. n., the first known Syndicus with strongly reduced eyes; and Syndicus (Semisyndicus) primus sp. n., the first Indian member of the subgenus Semisyndicus. An updated key to identification of Syndicus of India is given.

A new species of Peplomicrus Bernhauer from Ecuador (Coleoptera, Staphylinidae, Micropeplinae).

Peplomicrus nidicola sp. n., a new rove beetle species of the subfamily Micropeplinae is described and illustrated based on a series of males and females collected from nests of New World blackbirds (Icteridae) in northern Ecuador. It is the eleventh nominal species of this genus and the eighth known to occur in the Neotropical realm. A modification of Campbell's key to the Neotropical species of Peplomicrus Bernhauer is given to include P. nidicola, as well as a list of co-occurring coleopterofauna.

A unique case of commensalism: The beaver beetle Platypsyllus castoris (Leiodidae, Coleoptera) and its morphological adaptations.

Platypsyllus castoris is closely associated with beavers and displays a unique set of structural specializations. We document the morphology of adults with modern techniques, and interpret evolutionary changes linked with the specific life style. The small subfamily Platypsyllinae has evolved an entire suite of features correlated with a more or less close association with mammals, for instance a flattened body, a dorsal cephalic shield, flightlessness, eye reduction, and depigmentation. Within this small group, Platypsyllus displays numerous autapomorphic features, correlated with a close association with the beaver. Essential is a combination of mechanical stabilization and firm anchorage on the host, and efficient forward movement in the fur. Exo- and endoskeletal structures of the head and thorax are reinforced by vertical cuticular columns and by an array of internal ridges. The antennae are shortened and strongly modified, the mandibles distinctly reduced and flattened, unsuitable for cutting, scraping or grinding. The musculature of the mouthparts is simplified, whereas an enhanced set of prepharyngeal and pharyngeal dilators forms an efficient sucking pump. The prothoracic musculature is strongly developed. In contrast, the pterothoracic muscle system is distinctly simplified, even though leg muscles are strongly developed. Using the legs, the flattened beetles move sideways through the dense fur of the beaver, using posteriorly directed groups of setae and ctenidia to prevent being pushed backwards by the densely arranged hairs. In contrast to the anterior body, the cuticle of the abdomen is thin, and the entire tagma flexible, with thin layers of segmental muscles. The hind gut is not connected with the mid gut. The beetles probably consume liquid, possibly with emulgated minute skin debris. As the morphology of the mouthparts excludes damage to the skin of the host, the association should not be addressed as ectoparasitic but as commensalism.

The thoracic anatomy of Pselaphus heisei (Pselaphinae, Staphylinidae, Coleoptera).

We document external and internal thoracic structures of the free-living pselaphine beetle Pselaphus heisei (Pselaphitae) using a set of traditional and modern techniques. Like in the specialized myrmecophile Claviger testaceus (Clavigeritae), the skeletal elements of the pro- and pterothorax are highly compact, with largely reduced inter- and intrasegmental sutures. Features previously listed as synapomorphies of staphylinid subgroups, to which Pselaphinae belong, are confirmed for P. heisei. The only previously proposed thoracic synapomorphy of Pselaphinae, the mesoventral foveae, is likely transformed in P. heisei: we assume that the concavities are directed mesad and internally fused, thus forming a broad channel ("perforation") extending through the keel-like median region of the mesoventrite. The prothoracic foveal system is strongly reduced, with only one pair of pits present in front of the procoxae. Their internal invaginations form a transverse ventral endoskeletal bar that stabilizes the prothorax. The condition observed in the free-living P. heisei is in contrast with previous hypotheses linking the reduction of the foveal system with myrmecophily. Moreover, traces of the mesoventral foveae are even preserved in the highly specialized inquiline C. testaceus. Gland cells are associated with areas of hyaline squamose setae on different body regions, suggesting release of secretions on the ventral side of the head, pro- and mesothorax, and abdominal base. Similar specialized setal patches are common in Pselaphini and related groups within Pselaphitae. The prothoracic musculature in P. heisei is more complex than that in the myrmecophilous C. testaceus and the free-living, unspecialized Creophilus maxillosus (Staphylininae). The metathoracic muscle system is strongly simplified, demonstrating that P. heisei cannot fly, even though wings, some skeletal elements of the flight apparatus, and some small direct flight muscles are preserved. It cannot be fully excluded that indirect flight muscles and thus a functional flight apparatus is preserved in a certain percentage of individuals.

Evolution of cephalic structures in extreme myrmecophiles: a lesson from Clavigeritae (Coleoptera: Staphylinidae: Pselaphinae).

Pselaphinae is a large subfamily, comprising over 10 000 species of the megadiverse Staphylinidae (rove beetles). A remarkable feature of this group is the extreme structural diversity of different body regions, especially the head and its appendages. Within Pselaphinae, Clavigeritae stand out as a clade of highly specialized myrmecophiles. We examined internal and external head structures of the clavigerite species Diartiger kubotai Nomura, using state-of-the-art techniques. The cephalic morphology indicates in a phylogenetic context that the loss of eyes in some Clavigeritae was the latest of major evolutionary changes. We compiled the largest set of morphological data ever scored for the subfamily, comprising 155 characters of the head. Parsimony analyses and Bayesian inference yielded a similar phylogenetic pattern, largely congruent with results published previously. We retrieved Pselaphinae as a clade, and Faronitae as sister to all remaining groups of the subfamily. Faronitae are followed by a "Euplectitae grade" and non-monophyletic Goniaceritae, Batrisitae and Pselaphitae. Clavigeritae are monophyletic, but have evolved within the pselaphite grade. The enigmatic Colilodion Besuchet, recently shifted from Clavigeritae to a paraphyletic Pselaphitae, was placed as sister to extant clavigerites based on an array of cephalic synapomorphies. The current classification of Pselaphinae is unstable and deep changes should be made maintaining only monophyletic units, whereas most of the supertribes are paraphyletic. Characters of the head, with a concentration of mouthparts and sensory structures, and essential parts of the digestive tract and the nervous system, are highly informative phylogenetically. Study of internal structures, presently still at a very preliminary stage, obviously is essential for understanding the evolution of Pselaphinae. Future genetic investigations may reveal mechanisms behind the unique structural megadiversity in this exceptional group of rove beetles.

A warmth-loving brother of northern siblings: the first subtropical species of Forinus Kurbatov discovered on Okinawa-jima, Japan (Coleoptera, Staphylinidae, Pselaphinae).

To date, Forinus Kurbatov included only two species, known to occur in the Russian Far East: Primorye and Kunashir Island of the Kuril archipelago. Forinus mirus sp. n. is described, based on specimens collected on the subtropical island of Okinawa Island, Japan, ~2,000 km south of the nearest previously known locality of this genus. Morphological structures of the new species are illustrated in detail and remarks on the primary diagnostic feature of the tribe Trichonychini, the sternite IX with the unpaired median penial plate, is discussed.

The first record of Mexiconnus Jaloszynski in Costa Rica with description of a new species (Coleoptera, Staphylinidae, Scydmaeninae).

To date, Mexiconnus Jaloszynski was a monotypic genus known to occur in Chiapas, Mexico. The sole species, M. mexicanus (Franz), was unique among Stenichnini in having strongly broadened protarsi with a conspicuous setal cushion on the ventral side of the protarsomere 1. A new species, M. triops sp. n., is described, based on a male collected in central Costa Rica. In contrast to the type species of the genus, the male of M. triops is wingless, microphthalmous and depigmented, a set of features that suggest a possible endogean life habit.

Taxonomy of 'Euconnus complex'. Part XXIV. Intermediate forms between Psomophus, Eupentarius and Euconnus s. str. in the East Palaearctic fauna unify problematic subgenera (Coleoptera, Staphylinidae, Scydmaeninae).

Within the West Palaearctic region, the subgenera Psomophus and Eupentarius can be easily distinguished from Euconnus s. str. based on the antennal, pronotal and male genital structures. However, in other regions, described and undescribed species of Euconnus can be found that show intermediate features between these three subgenera. This problem is analyzed based on fourteen exemplary species that occur in the East Palaearctic region, mainly in Japan. It is concluded that there are intermediate forms between a trimerous antennal club, previously treated as the primary diagnostic feature of Psomophus, and a tetramerous club, typical of most species placed in Eupentarius and Euconnus s. str. The shape of the pronotum, the median pronotal antebasal pit, and the bifurcate aedeagal apex, thought to be typical of Eupentarius, were also found to vary among apparently closely related species. Consequently, Psomophus syn. n. and Eupentarius syn. n. are placed as junior synonyms of Euconnus s. str. The following species are redescribed or described: (1) Euconnus callidus group: E. chinensis Franz (China: Fujian), E. multiinsularis sp. n. (Japan: C & N Ryukyu); (2) species sola E. rectitibia sp. n. (Japan: Honshu, Kyushu); (3) Euconnus kirin group: E. kirin sp. n. (Japan: Honshu), E. yaimanus sp. n. (Japan: S Ryukyu), E. uchinaanchu sp. n. (Japan: C Ryukyu); (4) Euconnus pseudotrimerus group: E. pseudotrimerus sp. n. (Japan: Honshu), E. urauchianus sp. n. (Japan: S Ryukyu); (5) Euconnus taiwanus group: E. taiwanus Franz (Taiwan and newly recorded from Japan: S Ryukyu), E. fukiensis Franz (China: Fujian), E. bibaculatus sp. n. (Japan: S Ryukyu), E. cryptoiriomotensis sp. n. (Japan: S Ryukyu), E. oitaensis sp. n. (Japan: Kyushu), and E. banana sp. n. (Japan: C Ryukyu). A synonymic checklist of subgenera of Euconnus and a preliminary illustrated key to subgenera are given.

Taxonomy of 'Euconnus complex'. Part XXII. Status of subgenera Allonapochus Franz, Dimorphoconnus Franz, Eupentarius Reitter, and Myrmecodytes Croissandeau (Coleoptera, Staphylinidae, Scydmaeninae).

Type specimens of the type species of Allonapochus Franz, Dimorphoconnus Franz, Eupentarius Reitter, and Myrmecodytes Croissandeau were examined. As a result, Allonapochus is placed as a junior synonym of Napochus Thomson; Dimorphoconnus is placed as a junior synonym of Tetramelus Motschulsky; Euconophron Reitter is placed as a junior synonym of Eupentarius Reitter; and Myrmecodytes is placed as a junior synonym of Euconnus s. str. In addition, comparisons of differences and similarities between Tetramelus-like subgenera of Euconnus resulted in placing Heteroconnus Franz and Paratetramelus Franz as junior synonyms of Tetramelus. A lectotype is designated for Scydmaenus pharaonis Motschulsky.

Six new species of the Oriental genus Hlavaciellus Jaloszynski (Coleoptera, Staphylinidae, Scydmaeninae).

Six new species of the cephenniine genus Hlavaciellus Jaloszynski are described: H. cincinnalis sp. n. (Malaysia: Sabah); H. carinatus sp. n. (Malaysia: Pahang); H. microtuberculatus sp. n. (Malaysia: Pahang); H. diversipilosus sp. n. (Malaysia: Pahang); H. concavus sp. n. (Indonesia: Sumatra); and H. sumatranus sp. n. (Indonesia: Sumatra). An updated key to identification of males of all nominal species of Hlavaciellus is given.

Four new species of Pomphopsilla Jaloszynski in Rwanda, Burundi and DR Congo (Coleoptera: Staphylinidae: Scydmaeninae).

The cephenniine genus Pomphopsilla currently comprises seven nominal species distributed in Kenya, DR Congo and the Seychelles. Four new species are described: P. punctata sp. n. (Rwanda), P. cyanguguana sp. n. (Rwanda), P. kivuana sp. n. (DR Congo), and P. burundiana sp. n. (Burundi). Key characters of each species are illustrated, and the distribution of Pomphopsilla is summarized.

Revision of the subfamily Ostomopsinae (Coleoptera: Cerylonidae).

The subfamily Ostomopsinae of Cerylonidae is revised. Six nominal species are recognized and described or redescribed: Ostomopsis cudak sp. n. (Thailand), O. kuscheli sp. n. (New Caledonia), O. neotropicalis Lawrence Stephan (USA: Florida; Mexico: San Luis Potosi, Veracruz; Panama, Cuba, Hispaniola, Jamaica, Guadeloupe, Montserrat), O. solitaria Scott (Seychelles, New Caledonia, Christmas Island, Northern Mariana Islands), O. solomon sp. n. (Solomon Islands), and O. watti sp. n. (New Caledonia). Morphological structures of the type species of Ostomopsis are illustrated and described in detail, and identification key to Ostomopsis species is given.

Cephenniini of the Philippines. Part 5. Three new species of Cephennomicrus Reitter (Coleoptera, Staphylinidae, Scydmaeninae).

Cephennomicrus Reitter of the Philippines is exceptionally poorly known, with only four nominal species recorded so far, two on Luzon, one on Palawan, and one on Leyte. Three more new species are described: C. palawanicus sp. n. (Palawan), C. impressus sp. n. (Palawan), and C. lagunensis sp. n. (Luzon). The latter species is unusual among all congeners in having a monstrously elongate aedeagus, longer than the abdomen.

In the twilight zone-The head morphology of Bergrothia saulcyi (Pselaphinae, Staphylinidae, Coleoptera), a beetle with adaptations to endogean life but living in leaf litter.

The pselaphine Bergrothia saulcyi shows features seemingly linked with life in deep soil layers, such as greatly reduced and non-functional compound eyes, a sensorium of long tactile setae, long appendages, and flightlessness. However, the tiny beetles occur in forest leaf litter, together with a community of beetles with wings and well-developed eyes. We hypothesize that B. saulcyi moves into deep soil under dry conditions, and returns to upper layers when humidity increases again. Despite the evolutionary cost of a reduced dispersal capacity, this life strategy may be more efficient and less hazardous than moving to different habitats using flight and the visual sense in an environment periodically drying out. We also discuss cephalic features with potential phylogenetic relevance. Plesiomorphies of B. saulcyi include the presence of anterior tentorial arms, well-developed labral retractors, and a full set of extrinsic maxillary and premental muscles. Apomorphic cephalic features support clades Protopselaphinae + Pselaphinae, and Pselaphinae. A conspicuous derived condition, the clypeo-ocular carina, is a possible synapomorphy of Batrisitae and genera assigned to Goniaceritae. A complex triple set of cephalic glands found in B. saulcyi is similar to a complex identified in the strict myrmecophile Claviger testaceus (Clavigeritae). It is conceivable that glands linked with food uptake in free-living pselaphines were genetically re-programmed in ancestors of inquilines, to enable them to appease the host ants. We suggest that behavioral studies are necessary to understand the poorly known life habits of B. saulcyi. Additional information is required to explain why a species with irreversibly reduced visual sense and other adaptations typical of endogean or cave-dwelling beetles was only collected from the upper leaf litter layer.