Early detection of invasive species allows for a more rapid and effective response. Restoration of the native ecosystem after an invasive population has established is expensive and difficult but more likely to succeed when invasions are detected early in the invasion process. Containment efforts to prevent the spread of known invasions also benefit from earlier knowledge of invaded sites. Environmental DNA (eDNA) techniques have emerged as a tool that can identify invasive species at a distinctly earlier time point than traditional methods of detection. Here, we focus on whether eDNA techniques can be successfully applied to detect new invasions by the destructive New Zealand Mud Snail Potamopyrgus antipodarum (NZMS). It is an opportune time to apply eDNA-based detection in P. antipodarum, which is currently expanding its invasive range across eastern North America. We collected water samples from eight sites in central Pennsylvania that prior evidence indicated were not yet invaded by the NZMS but were part of the same watershed as other previously documented invaded sites. We found evidence for NZMS invasion at five of the eight sites, with subsequent physical confirmation of mud snails at one of these sites. This study is the first example of successful application of eDNA to detect a previously unidentified invasive population of NZMS, setting the stage for further monitoring of at-risk sites to detect and control new invasions of this destructive snail. This study also shows potential opportunities for invasion monitoring offered by using low-cost efforts and methods that are adaptable for citizen science.

入侵物种的早期检测允许更快速和有效的反应。在入侵种群建立后恢复本地生态系统既昂贵又困难，但在入侵过程的早期检测到入侵时更有可能成功。防止已知入侵传播的遏制措施也受益于对入侵地点的早期了解。环境 DNA (eDNA) 技术已成为一种工具，可以在比传统检测方法明显更早的时间点识别入侵物种。在这里，我们关注的是 eDNA 技术是否可以成功地应用于检测破坏性新西兰泥螺 Potamopyrgus antipodarum (NZMS) 的新入侵。现在是在P. antipodarum中应用基于 eDNA 的检测的好时机，目前正在扩大其在北美东部的入侵范围。我们从宾夕法尼亚州中部的 8 个地点收集了水样，先前的证据表明 NZMS 尚未入侵，但与其他先前记录的入侵地点属于同一流域的一部分。我们在八个地点中的五个发现了 NZMS 入侵的证据，随后在其中一个地点物理确认了泥螺。这项研究是第一个成功应用 eDNA 来检测以前身份不明的 NZMS 入侵人群的例子，为进一步监测高危地点以检测和控制这种破坏性蜗牛的新入侵奠定了基础。这项研究还显示了通过使用适用于公民科学的低成本努力和方法提供的入侵监测的潜在机会。