Comparative studies require understanding the dispersal and movement capacity of species. However, it is not often possible to obtain information on this key life-history attribute in insects. Rove beetles (Staphylinidae) are the second most abundant group of epigeal invertebrates, and little is known about their dispersal abilities in tropical regions. We explored the relationship between six linear morphological body-size traits and three wing measures from 48 necrophilous rove beetle species for fitting univariate linear regression models. Pronotal width was the more accurate morphological variable to predict the wing traits of necrophilous rove beetle species. Models of wing area were a better fit when data had been sorted according to subfamily. The models obtained can be used to estimate length, width, and area of the necrophilous staphylinid species' wings. Morphological traits are useful as a proxy for dispersal in comparative ecological and evolutionary studies.

Acicnemis ryukyuana Lewis, new species is described from Okinawa Island and Ishigaki Island, Japan. Although A. ryukyuana is most appropriately placed within the genus Acicnemis Fairmaire based on external and genital morphology, notably the third tarsomere is not prominently emarginate as in most of its congeners. High-resolution stacked photographs are included along with a description of this morphologically distinct new species.

New state, province, territory, and northern records are given for Nearctic Leiodidae. The new records are for the genera Nemadus Thomson (Cholevinae, Anemadini); Catops Paykull (Cholevinae, Cholevini); Colon Herbst (Coloninae); Agathidium Panzer, Anisotoma Panzer (Leiodinae, Anisotomini); Anogdus LeConte, Cyrtusa Erichson, Leiodes Latreille, Liocyrtusa Daffner (Leidodinae, Leiodini); ColenisErichson (Leiodinae, Pseudoliodini); Hydnobius Schmidt, Macrohydnobius Peck and Cook, Pseudotriarthron Normand, and Triarthron Märkel (Leiodinae, Sogdini).

Dung beetles exhibit a wide range of trophic preferences, including soft and hard resources. The study of mouthparts associated with these resources is extensive, and mouthparts of these insects have generally been described as membranous, hairy, and poorly adapted to cutting hard food. In this study, we compare the mouthparts (epipharynx, labium, and hypopharynx) of five species of Dichotomius Hope from Argentina that show differences in their trophic preferences, to evaluate if these structures also differ according to their feeding habit. We found epipharyngeal teeth, hypopharyngeal teeth, and more sclerotized structures in species that consume hard resources [Dichotomius carbonarius (Mannerheim)] and the absence or reduction of these structures in species that consume soft resources [Dichotomius sericeus (Harold), Dichotomius nisus (Olivier), Dichotomius mormon (Ljungh), and Dichotomius depressicollis (Harold)]. On the other hand, the latter species have hairier and softer mouth structures associated with these soft resources. According to these results, a detailed study of the macrostructures of mouthparts could indicate a priori the resource state consumed by a dung beetle species: the presence or absence of teeth and sclerotized structures would be associated with hard or soft food as the main resource, respectively, despite the occasional use of other resources in the field.

This paper is the fourth in a series of studies on the genus Trachys Fabricius from China. It reports the results of a collecting survey of the fauna in Jiangxi Province, China. Altogether, 27 species and subspecies were collected and identified. Detailed distribution data are presented for all species and subspecies recorded from Jiangxi Province, fifteen of which represent new records for the province and two of which are considered new species and are described and illustrated herein: Trachys jinpenshanensis Peng, new species; Trachys parviformis Peng, new species.

Surveys for beetles and plant-associated insects on San Clemente Island off southern California conducted by the California Beetle Project and the Santa Barbara Botanic Garden found four specimens of an unknown bark beetle species. Based on morphology, the beetle was identified as a Carphobius Blackman species. Given the uncharacteristic scale-like setae, generic placement was confirmed in the context of a molecular phylogeny using partial sequences of COI and 28S genes. Carphobius was sister to Chaetophloeus LeConte (Chaetophloeini) which calls into question its current tribal placement in Polygraphini. Carphobius caterinoi Cognato and Smith, new species is described and compared to the three previously known Carphobius species and similar genera. Carphobius is reviewed and a key to species and images are included. Potential host use by C. caterinoi is discussed.

A new flightless click beetle species, Pseudocsikia douglasi Hoffmannova and Qiu, new species, is described and illustrated from Taiwan Island. Its habitus and diagnostic characters are illustrated. This new species belongs to the Pseudocsikia formosana-species group, of which all species are endemic to Taiwan Island. Additionally, we update the identification key to the species of P. formosana-species group.