Federal Approval Granted for Field Release of Murakami Knotweed Psyllid to Combat Invasive Fallopia Species

The Animal and Plant Health Inspection Service APHIS announced its decision to authorize the field release of a new biological control agent, Aphalara itadori from Murakami Japan. This initiative aims to curb the spread of invasive Japanese giant and Bohemian knotweeds which pose significant ecological and economic threats across the contiguous United States. The announcement on June 22 2026 marks a crucial step in federal efforts to manage these widespread foreign plant species, following extensive environmental assessments. This notice details the agency's Finding of No Significant Impact, greenlighting the deployment of a specific psyllid biotype believed to be particularly effective in target regions.

The Persistent Challenge of Invasive Knotweeds

Japanese giant and Bohemian knotweeds, collectively known as Fallopia japonica, F. sachalinensis, and F. x bohemica, were introduced to North America from Japan in the late 19th century. These vigorous herbaceous perennials have since proliferated across vast swathes of the continent with particularly dense infestations observed in the Pacific Northwest the US Northeast and eastern Canada. Their aggressive growth habits allow them to outcompete native flora severely altering local ecosystems. Along riverbanks and floodplains where they often thrive these plants can disrupt aquatic food webs and nutrient cycles impacting biodiversity and natural habitat integrity. The widespread nature of these infestations has necessitated a federal response focused on sustainable long-term management strategies.

Evolution of Biological Control Efforts

The search for an effective biological control agent against these invasive knotweeds has been ongoing. Early efforts by APHIS focused on two specific biotypes of the knotweed psyllid Aphalara itadori originating from Hokkaido and Kyushu Japan. In 2019 APHIS published an initial environmental assessment EA examining the potential impacts of releasing these biotypes. This was followed by a Finding of No Significant Impact FONSI in November 2020 which paved the way for permits for those initial biotypes.

However in June 2021 a request was submitted to consider a third biotype of Aphalara itadori sourced from Murakami Japan. Proponents of the Murakami line argued for its superior efficacy citing several key advantages. This biotype is native to a climate and photoperiod more closely aligned with the primary knotweed-infested regions of the United States potentially leading to better adaptation and establishment. Crucially it is also a recently collected field-adapted strain unlike the previously permitted lab-adapted lines which may have lost some vigor. Furthermore the Murakami psyllid demonstrates particular effectiveness against the hybrid knotweed F. x bohemica which is the most abundant knotweed type currently found in the United States. These characteristics suggested a more robust and targeted approach to knotweed management.

Rigorous Environmental Review and Federal Authorization

APHIS subjected the proposed release of the Murakami Aphalara itadori biotype to a comprehensive environmental review process. On February 10 2023 the agency published a supplemental EA for public comment seeking input on the potential environmental impacts of this specific release. The public comment period closed on March 13 2023 yielding nine comments all of which were supportive of the proposed release. Feedback came from a diverse array of stakeholders including State Tribal and local agricultural agencies non-governmental organizations and private citizens. One commenter specifically advised a gradual introduction of the psyllid with continuous monitoring to prevent unforeseen effects a strategy which APHIS confirmed is integral to its implementation plan and detailed in Appendix 2 of the final supplemental EA.

After thorough consideration of the supplemental EA and public feedback APHIS concluded that the release of the Murakami biotype will not have a significant impact on the quality of the human environment. This determination led to the issuance of a Finding of No Significant Impact FONSI for this specific strain eliminating the need for a more extensive Environmental Impact Statement. Consequently APHIS has authorized the necessary permits for the field release of the Murakami Aphalara itadori across the contiguous United States. This decision adheres to the legal frameworks established by the National Environmental Policy Act of 1969 NEPA as amended relevant regulations from the Council on Environmental Quality and USDA as well as APHIS' own NEPA Implementing Procedures. The final supplemental EA and FONSI are publicly accessible through Regulations.gov and at USDA facilities in Washington DC providing full transparency in the federal decision-making process.

Looking Ahead in Invasive Species Management

The approval for the Murakami Aphalara itadori marks a targeted enhancement to the ongoing federal strategy for biological control of invasive knotweeds. This carefully considered approach seeks to leverage natural enemies to restore ecological balance in areas impacted by these aggressive plants. The emphasis on a gradual monitored release is critical to ensuring both the efficacy of the biocontrol agent and the safeguarding of non-target species and ecosystems. The long-term success of this initiative will depend on continued scientific observation and adaptive management. It underscores a federal commitment to addressing complex environmental challenges through evidence-based interventions. This program serves as a template for future efforts in invasive species management where comprehensive environmental assessments are paired with strategic biological solutions.