Sei-Woong Choi

Island ecosystems provide natural laboratories for understanding patterns of biodiversity, species turnover and the ecological processes shaping community assembly. Moths (Lepidoptera) are amongst the most diverse insect groups and play important ecological roles as herbivores, pollinators and prey for higher trophic levels, making them valuable indicators of environmental change. Although numerous ecological studies have examined moth diversity in continental forests, standardised long-term datasets spanning multiple islands remain scarce, particularly in East Asia. To facilitate studies of island biogeography, temporal community dynamics and biodiversity conservation, we compiled a standardised dataset of moth community composition from islands along the southern coast of the Korean Peninsula. This dataset contains standardised light-trap survey records collected from 332 sites on 30 islands between 2007 and 2025, encompassing 1,179 moth species from 19 families and 30,442 individuals. Most islands are located within two marine national parks, providing broad coverage across gradients of island area, isolation and elevation. The dataset includes site-level species abundance matrices, island-level environmental variables (area, distance from the mainland and maximum elevation), survey metadata and taxonomic information for all recorded species. Each island was surveyed in one to four discrete years, enabling analyses of both spatial variation amongst islands and temporal variation within islands. This dataset provides a valuable resource for studies of island biogeography, community assembly, biodiversity monitoring, environmental change and conservation prioritisation of insular insect communities.

Genetic divergence along elevational gradients between mainland and island populations provides an opportunity to test the island genetic erosion model, which predicts reduced genetic diversity and increased differentiation in island populations. We examined two moth species, a geometrid moth ( Alcis angulifera ) and an erebid moth ( Hydrillodes morosa ), sampled along elevational gradients on Mt. Jirisan (mainland) and Mt. Hallasan (island) in southern South Korea. A total of 155 individuals were analyzed using mitochondrial cytochrome oxidase subunit I (mt COI) sequences. We identified 61 haplotypes across both species. A. angulifera exhibited similarly high genetic diversity on the mainland and island, whereas H. morosa showed overall lower diversity relative to A. angulifera but pronounced regional differences, with significantly higher haplotype and nucleotide diversity on the island. Mantel tests revealed significant genetic divergence between mainland and island populations but not within individual mountains, suggesting ongoing gene flow within elevational gradients. AMOVA indicated moderate differentiation in A. angulifera (F _CT = 0.08) and stronger differentiation in H. morosa (F _CT = 0.14), with most genetic variation occurring within populations. Gene flow estimates further highlighted contrasting patterns, with high connectivity in A. angulifera (Nm = 5.49) and restricted migration in H. morosa (Nm = 0.08). Together, these results indicate that while A. angulifera maintains genetic cohesion across regions, H. morosa exhibits stronger geographic and elevational structuring due to limited gene flow. Our findings do not support a universal reduction in genetic diversity in island populations; instead, they highlight the importance of species-specific ecological traits and geographic context in shaping genetic diversity patterns, suggesting that the island genetic-erosion pattern is more context-dependent than previously appreciated.

This study investigates temporal changes in moth diversity and community composition within plantation ecosystems, evaluates their comparative status relative to regrowth forest habitats, and examines the differential responses of distinct moth taxa along successional gradients. Moth communities were sampled using standardized black light traps at 22 forest sites in southern Korea, representing early-stage plantations (EP, 1–3 years), mid-stage plantations (MP, 10–12 years), and regrowth forests (RF). Sampling was conducted monthly from May to September (excluding July) in 2023–2024. A total of 8075 individuals from 650 species and 22 families were recorded. Species richness ( q = 0) was highest between EP and MP, while Shannon ( q = 1) and Simpson ( q = 2) diversity in MP matched those of RF. Community composition differed significantly in EP, with MP converging toward RF. All-sized moths showed stronger separation among forest types. Family- and subfamily-level patterns showed that Crambidae and Erebinae were abundant in EP, whereas Geometridae, Pyralidae, and Bryophilinae (Noctuidae) were abundant in MP or RF. At the species level, six species were identified to differentiate among plantation types. This suggests that responses to plantation age are more clearly expressed at higher taxonomic levels than at the species level. Moth diversity and composition can substantially recover within a decade after plantation establishment. Older plantations may serve as valuable habitats, supporting biodiversity conservation in managed forest landscapes.

The tribe Anerastiini in Korea comprises eight species in seven genera: Hypsotropa solipunctella, Enosima leucotaniella, Rhinaphe minor, Emmalocera venosella, Paraemmalocera gensanalis, Maliarpha borealis, Arivaca cuprella, and Arivaca gracilis. Among them, we reviewed four genera, Enosima, Polyocha, Toshitamia, and Paraemmalocera, of the tribe in Korea, and report two new species of Paraemmalocera, one new species of Polyocha, and one new record of Toshitamia for the first time in Korea. Diagnoses, adult figures, and illustrations of male and female genitalia are provided, as well as DNA Barcoding data.

Many insect species are at risk of extinction due to habitat degradation and loss, the introduction of invasive species, and climate change. Butterfly populations, in particular, have declined worldwide. Our study analyzed changes in the six landscape features across sites where 18 threatened butterfly species were recorded over 40 years (1987–2018). We observed a significant expansion of developed areas accompanied by a marked decline in agricultural areas, leading to notable changes in habitat composition. Additionally, areas supporting more than two endangered (EN) butterflies, along with vulnerable (VU) and near‐threatened (NT) butterflies, showed a significant reduction in grassland cover, underscoring the importance of grassland for sustaining threatened butterflies. Following a review of the status of threatened butterflies in Korea, we examined the impacts of habitat change, forest succession, cultural changes (e.g., burial preferences), and climate change on the decline of butterflies in Korea.

As a Long-Term Ecological Network project in Korea, we conducted monthly macromoth sampling from May to October, 2016–2023, in Namsan Park, Seoul, at three permanent plots representing dominant tree communities: Quercus mongolica, Robinia pseudoacacia, and Pinus densiflora forests. Over eight years, we recorded 3,486 individuals from 283 species in 11 families. In total, 351 macromoth species from 13 families were documented in the city park, including 212 newly discovered species and 68 previously recorded species now disappearing. Species richness and abundance varied among the three forest types, with the Q. mongolica forest showing the highest values in both species and individuals. Overall species richness showed a nonsignificant decline, and auto regressive integrated moving average models predicted ongoing fluctuations in richness and a rising trend in abundance in the coming years. Macromoth assemblages in Namsan exhibited distinct clustering by forest type, with consistent distribution of body size groups emphasized throughout the study. Furthermore, relatively high faunal turnover within forests, combined with minimal annual variation, suggests a trend toward homogenization of macromoth assemblages across forest types. This pattern appears to be influenced by the city park’s isolation, which may limit species dispersal and contribute to localized faunal differentiation.