Tanney, Joey B.Kemler, MartinVivas, MariaWingfield, Michael J.Slippers, Bernard2026-04-242026-04-242025-07Tanney, J.B., Kemler, M., Vivas, M. et al. 2025, 'Silent invaders : the hidden threat of asymptomatic phytobiomes to forest biosecurity', New Phytologist, vol. 247, no. 2, pp. 533-545. DOI: 10.1111/nph.70209.0028-646X (print)1469-8137 (online)10.1111/nph.70209http://hdl.handle.net/2263/109752SUPPORTING INFORMATION : Table S1 Examples of invasive pathogens with latent/endophytic life histories that were introduced outside of their native range via P4P pathway, with records of first detections.Populations of diverse, unknown, and potentially pathogenic fungi and fungus-like organisms are continuously introduced into new locations via asymptomatic infections (e.g. as endophytes or latent pathogens) within internationally traded live plants. Interactions between these asymptomatic fungi and novel recipient host trees can be unpredictable, and urban introductions may act as bridgeheads into natural and managed forests. Historical examples of novel, highly destructive forest tree diseases highlight the potential threat of this pathway. As the trade in live plants continues to expand, the likelihood of high-impact incursions increases. This has led to calls for more proactive management, including more stringent treatment and regulatory standards, and even the phasing out of trade in plants determined to be an untenable risk to forest ecosystems. In this review, we discuss how biosecurity systems should consider advances in understanding the diversity and ecology of phytobiomes associated with asymptomatic plants and what measures can be considered to reduce this threat to global forest health.en© 2025 His Majesty the King in Right of Canada and The Author(s). This article is licensed under a Creative Commons Attribution 4.0 International License.Biological invasionsEndophytesForest invasive alien speciesForest pathogensFungal pathogensPhytopathogensPhytosanitary regulationsTrade pathwaysArticle