Phytophthora ×alni (Brasier & S.A. Kirk) Husson, Ioos & Marçais (Husson et al. 2015)
Alder dieback, alder decline
First identified in Europe (Aguayo et al. 2013)
European introductions occurred through infected nursery stock (Adams et al. 2008)
Infects and kills alder trees (trees of the genus Alnus) (Gibbs et al. 1999)
Distribution / Maps / Survey Status
USDA. APHIS. Cooperative Agricultural Pest Survey. National Agricultural Pest Information System.
USDA. APHIS. Plant Protection and Quarantine.
A Federal Order is a legal document issued in response to an emergency when the Administrator of APHIS considers it necessary to take regulatory action to protect agriculture or prevent the entry and establishment into the United States of a pest or disease. Federal Orders are effective immediately and contain the specific regulatory requirements.
Google. YouTube; Swedish University of Agricultural Sciences. Department of Forest Mycology and Plant Pathology.
The section below contains highly relevant resources for this species, organized by source. Or, to display all related content view all resources for Alder Dieback.
USDA. APHIS. PPQ. CPHST. Identification Technology Program.
Adams, G.C., M. Catal, L. Trummer, E.M. Hansen, P. Reeser, and J.J. Worrall. 2008. Phytophthora alni subsp. uniformis found in Alaska beneath thinleaf alders. Plant Health Progress.
Aguayo, J., G.C. Adams, F. Halkett, M. Catal, C. Husson, Z.A. Nagy, E.M. Hansen, B. Marcais, and P. Frey. 2013. Strong genetic differentiation between North American and European populations of Phytophthora alni subsp. uniformis. Phytopathology 103(2):190-199.
Gibbs, J.N., M.A. Lipscombe and A.J. Peace. 1999. The impact of Phytophthora disease on riparian populations of common alder (Alnus glutinosa) in Southern Britain. European Journal of Forestry 29(1):1-88.
Husson, C., et al. 2015. Evidence for homoploid speciation in Phytophthora alni supports taxonomic reclassification in this species complex. Fungal Genetics and Biology 77:12-21.