Reductions in Aquatic Insect Diversity from Anthropogenic Stressors Occur across Subtropical and Tropical Islands in East Asia

The subtropical and tropical islands of East Asia host a unique and highly endemic aquatic in-sect fauna threatened by a variety of anthropogenic stressors (e.g., invasive species, habitat frag-mentation, pollution, and climate change). This review synthesizes the impacts of these stressors on aquatic insect diversity across this region based on 206 articles published over the past 40 years (1985–2025) to evaluate the impacts of these stressors on insular aquatic insect diversity. The islands of East Asia include all or parts of China, Japan, Taiwan, and South Korea. The an-nual number of publications demonstrates a steady upward trend over time, and is accelerating in the last decade. Our systematic analysis reveals a large geographic disparity. Research is heavily concentrated on major islands, with Honshu island (42%) and Taiwan island (24%) accounting for two-thirds of the total literature, while small islands (<10,000 km2) comprise only 20%. Fur-thermore, current research tends to focus on independent impacts of single stressors, largely overlooking the complex additive, synergistic, or antagonistic interactions that characterize stressors on these fragile ecosystems. These research gaps, compounded by a lack of long-term monitoring data (i.e., only ~22% of the studies span more than 3 years), hinder efforts to distin-guish natural inter-annual variability from anthropogenic shifts. The extinction of cryptic or en-demic species may occur before these species are identified and described. In addition, the dis-entanglement of these interactive impacts on aquatic insect communities in East Asian islands is critical for predicting ecosystem responses to further local and global changes. Identification of non-linear ecological tipping points through these long-term monitoring networks, coupled with proactive, science-guided habitat restoration, is essential to mitigate imminent extinctions and to rebuild the functional integrity of these imperiled freshwater ecosystems.东亚亚热带与热带岛屿拥有独特且高度特有化的水生昆虫区系（aquatic insect fauna），该类区系正受到多种人为胁迫因子（anthropogenic stressors）的威胁，例如外来入侵物种（invasive species）、栖息地破碎化（habitat fragmentation）、污染以及气候变化（climate change）。本综述基于1985年至2025年近40年间发表的206篇文献，综合梳理了上述胁迫因子对该区域水生昆虫多样性的影响，旨在评估此类因子对岛屿水生昆虫多样性的作用。东亚岛屿涵盖中国全境或部分区域、日本、中国台湾地区以及韩国。年度发表文献数量随时间呈现稳步上升趋势，且近十年增速进一步加快。我们的系统分析（systematic analysis）显示该领域研究存在显著的地理不均衡性：研究高度集中于大型岛屿，其中本州岛（Honshu，42%）与中国台湾岛（Taiwan，24%）的相关文献占总文献量的三分之二，而面积小于10000平方千米的小岛相关研究仅占20%。此外，当前研究多聚焦于单一胁迫因子的独立影响，很大程度上忽视了表征这些脆弱生态系统中胁迫因子间复杂的叠加（additive）、协同（synergistic）或拮抗（antagonistic）交互作用。此类研究空白，加之长期监测数据（long-term monitoring data）的匮乏（仅约22%的研究时长超过3年），阻碍了我们区分自然年际波动（natural inter-annual variability）与人为驱动的生态变化（anthropogenic shifts）。许多隐存物种（cryptic species）或特有物种可能在被发现与描述之前就已走向灭绝。此外，厘清东亚岛屿水生昆虫群落所受的这些交互影响，对于预测生态系统对后续局地与全球变化的响应至关重要。通过此类长期监测网络识别非线性生态临界点（non-linear ecological tipping points），并辅以以科学为导向的主动栖息地修复（science-guided habitat restoration）工作，对于缓解迫在眉睫的物种灭绝危机、重建这些濒危淡水生态系统（imperiled freshwater ecosystems）的功能完整性至关重要。