The genus Bryaxis Kugelann (Goniaceritae: Bythinini) is the most species-rich genus of the subfamily Pselaphinae and is mainly distributed in the Palearctic region. Although previous studies have documented 14 species in the Korean Peninsula, the true diversity, ecology, and immature stages of the genus are still inadequately known. In this study, five new Korean species are described: B. grandinodussp. nov., B. uljinensissp. nov., B. fabaiformissp. nov., B. girinensissp. nov., and B. nemorosussp. nov. Illustrations of the habitus and other morphological details, and a distribution map are provided. In addition, Bryaxis leechanyoungi Nomura & Lee, 1993 is proposed as a new synonym of B. mahunkai Löbl, 1975 based on the original description and illustrations of diagnostic characters.

Although the high level of species diversity within the Pholcus phungiformes-group (Araneae: Pholcidae) in the Korean Peninsula has been recognized recently, taxonomic studies, including new species discovery, have not been conducted in western regions of South Korea. In this study, five additional species belonging to the Pholcus phungiformes-group discovered from Seoul and surrounding areas are described as new, viz., Pholcus seoulensis Lee & Lee, sp. nov. Pholcus suraksanensis Lee & Lee, sp. nov., Pholcus incheonensis Lee & Lee, sp. nov., Pholcus seokmodoensis Lee & Lee, sp. nov. and Pholcus chilgapsanensis Lee & Lee, sp. nov. Detailed descriptions and geographic distributions are provided with accompanying photographs.

Limnophilinae crane flies belonging to the genus Adelphomyia Bergroth, 1891 of the Korean Peninsula were studied starting from 1937, but only one species A. macrotrichiata (Alexander, 1923) has been recorded from North Korea so far. The genus was unknown from South Korea. Four species were found during our studies on the Peninsula, one of them from Jeju Island described as new, Adelphomyia jejuana Podenas, sp. nov. Three species are recorded from both northern and southern parts of the Peninsula. Specimens on which was based the record of A. macrotrichiata from North Korea was misidentified and no more specimens were collected; therefore, A. macrotrichiata is deleted from the Korean species list. Habitat, elevation range, and seasonality data is presented for each species. Images of taxonomically important morphological characters, and an identification key for all Palaearctic species of the genus Adelphomyia are presented. Distribution maps are presented for all Korean species.

Nine new species belonging to the Pholcus phungiformes-group are described from Korea, viz., Pholcus chugok Lee & Lee, sp. nov., Pholcus noeun Lee & Lee, sp. nov., Pholcus wonju Lee & Lee, sp. nov., Pholcus ungyo Lee & Lee, sp. nov., Pholcus hwangjeong Lee & Lee, sp. nov., Pholcus gimsatgat Lee & Lee, sp. nov., Pholcus solchi Lee & Lee, sp. nov., Pholcus mino Lee & Lee, sp. nov., and Pholcus maepo Lee & Lee, sp. nov. These new species were found from mountainous habitats in Gangwon-do and Chungcheongbuk-do, the northeastern regions of South Korea where the two major mountain ranges (Taebaeksan mountains and Sobaeksan mountains) are located together. Detailed descriptions, photographs, and a distribution map for the new species are provided with notes on their intraspecific variations of copulatory organs.

A new species of crane fly (Diptera, Limoniidae), Elephantomyia (Elephantomyia) hallasana Podenas & Podeniene, sp. nov., from Jeju Island, South Korea is described. Adult and larval characters are illustrated. Elephantomyia (E.) hallasana sp. nov. is the only species of the genus Elephantomyia Osten Sacken, 1860 recorded from Jeju Island, South Korea. Habitat, elevation range, and seasonality data are presented. Distributional notes on E. subterminalis Alexander, 1954 in the Far East of Russia (Khabarovskiy and Primorskiy regions) are discussed. An identification key for all Eastern Palaearctic species of subgenus E. (Elephantomyia) is presented.

We developed microsatellite markers for genetic structural analyses of Dorcus hopei, a stag beetle species, using next generation sequencing and polymerase chain reaction (PCR)-based genotyping for regional populations. A total of 407,070,351 base pairs of genomic DNA containing >4000 microsatellite loci except AT repeats were sequenced. From 76 loci selected for primer design, 27 were polymorphic. Of these 27 markers, 10 were tested on three regional populations: two Chinese (Shichuan and Guangxi) and one Korean (Wanju). Three markers were excluded due to inconsistent amplification, genotyping errors, and Hardy-Weinberg equilibrium (HWE). By multi-locus genotyping, the allele number, observed heterozygosity and polymorphism information content of seven microsatellite loci were ranged 2‒10, 0.1333‒1.0000, and 0.1228‒0.8509, respectively. In an analysis on the genetic differentiation among regional populations including one Japanese population and one cross-breeding population, the individual colored bar-plots showed that both Chinese populations were closer to each other than to the Far East Asian populations. In Far East Asian populations, Wanju and Nirasaki populations could not be distinguished from each other because the frequency of genetic contents was very similar in some individuals of two populations. Moreover, the cross-breeding population contained all patterns of genetic contents shown in Chinese, Korean, and Japanese populations, compared with the genetic content frequency of each regional population. As a result, we examined whether the cross-breeding population might be a hybrid population, and might contain a possibility of interbreeding with Chinese populations in parental generations. Therefore, these markers will be useful for analyses of genetic diversity in populations, genetic relationships between regional populations, genetic structure analyses, and origin tests.