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APHIS Issues Final Environmental Assessment for Biological Control of Japanese, Giant, and Bohemian Knotweeds

The U.S. Department of Agriculture’s Animal and Plant Health Inspection Service (APHIS) has issued the final environmental assessment (EA) for releasing Japanese knotweed psyllid (Aphalara itadori) to manage Japanese, giant, and bohemian knotweeds (Fallopia japonica, F. sachalinensis, and their hybrid, F. x bohemica). After careful analysis, APHIS has determined that releasing Japanese knotweed psyllid within the continental United States is not likely to have a significant impact on the environment. Based on this determination, APHIS will not prepare an environmental impact statement and will begin issuing permits for the release of Japanese knotweed psyllid.

Invasive knotweeds were introduced into North America from Japan during the late 19th century. Japanese, giant, and bohemian knotweeds are large herbaceous perennials, which have spread throughout much of North America. The greatest infestations are located in the Pacific Northwest, the Northeastern United States, and eastern Canada. Knotweeds have become especially problematic along the banks and floodplains of rivers and streams, where they crowd out native plants and potentially affect stream nutrients and disrupt local ecosystems. APHIS will issue permits for Japanese knotweed psyllid to help reduce the severity of invasive knotweed infestations in the United States. The knotweed-specific psyllid poses no risk to people or native wildlife.

The EA and finding of no significant impact may be viewed on the website along with APHIS’ response to comments received. For more information, visit:!docketDetail;D=APHIS-2019-0002-3.

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