Data from: Pleistocene sea level fluctuation and host plant habitat requirement influenced the historical phylogeography of the invasive species Amphiareus obscuriceps (Hemiptera: Anthocoridae) in its native range

Background: On account of repeated exposure and submergence of the East China Sea (ECS) land bridge, sea level fluctuation played an important role in shaping the population structure of many temperate species across the ECS during the glacial period. The flower bug Amphiareus obscuriceps (Poppius, 1909) (Hemiptera: Anthocoridae) is an invasive species native to the Sino-Japanese Region (SJR) of East Asia. We tested the hypothesis of the ECS land bridge acting as a dispersal corridor or filter for A. obscuriceps during the glacial period. Specifically, we tested whether and the extent to which dispersal ability and host plant habitat requirement influenced the genetic structure of A. obscuriceps during the exposure of the ECS land bridge.
Results: Phylogenetic and network analyses indicated that A. obscuriceps is composed of two major lineages, i.e., China and Japan. Divergence time on both sides of the ECS was estimated to be approximately 1.07 (0.79-1.32) Ma, which was about the same period that the sea level increased. No significant Isolation by Distance (IBD) relationship was found between Фst and Euclidean distances in the Mantel tests, which is consistent with the hypothesis that this species has a good dispersal ability. Our Last Glacial Maximum (LGM) niche modeling of plants that constitute preferred habitats for A. obscuriceps exhibited a similar habitat gap on the exposed ECS continental shelf between China and Japan, but showed a continuous distribution across the Taiwan Strait.
Conclusion: Our results suggest that ecological properties (habitat requirement and dispersal ability), together with sea level fluctuation during the Pleistocene across the ECS, have shaped the genetic structure and demographic history of A. obscuriceps in its native area. The host plant habitat requirement could also be a key to the colonization of the A. obscuriceps species during the exposure of the ECS land bridge. Our findings will shed light on the potential role of habitat requirement in the process of biological invasion in future studies.

背景：受东海（East China Sea, ECS）陆桥反复出露与淹没的影响，冰期海平面波动在塑造东海水域诸多温带类群的种群结构过程中发挥了关键作用。花蝽（Amphiareus obscuriceps，Poppius, 1909，半翅目：花蝽科）是分布于东亚中日区域（Sino-Japanese Region, SJR）的土著入侵物种。本研究旨在验证冰期东海陆桥对该物种兼具扩散廊道与过滤屏障功能的假说，并具体探究在东海陆桥出露时期，扩散能力与寄主植物生境偏好如何影响其遗传结构，以及相应的影响程度。
结果：系统发育与种群网络分析显示，A. obscuriceps可划分为两大支系，分别对应中国种群与日本种群。东海两岸种群的分化时间估算约为1.07（95%置信区间：0.79~1.32）百万年，与海平面上升时期大致重合。曼特尔检验结果显示，遗传分化指数Фst与欧氏地理距离之间未呈现显著的距离隔离（Isolation by Distance, IBD）模式，这与该物种具备较强扩散能力的假说相符。针对该物种偏好寄主植物的末次盛冰期（Last Glacial Maximum, LGM）生态位模型显示，中国与日本之间出露的东海大陆架存在相似的生境缺口，但台湾海峡区域的生境呈现连续分布格局。
结论：本研究结果表明，生态特性（生境偏好与扩散能力）结合更新世东海海平面波动，共同塑造了该物种在原生分布区的遗传结构与种群历史。在东海陆桥出露时期，寄主植物生境偏好或是A. obscuriceps成功定殖的关键因素。本研究结果可为未来探讨生境偏好在生物入侵过程中的潜在作用提供参考。