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National Invasive Species Information Center
U.S. Department of Agriculture
Home / Terrestrial Invasives / Terrestrial Pathogens and Diseases / Alder Dieback

Alder Dieback

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Phytophthora disease of alders (Alder dieback)
Phytophthora disease of alders (Alder dieback), symptoms - Photo by Andrej Kunca; Slovakia National Forest Centre
Scientific Name: 

Phytophthora ×alni (Brasier & S.A. Kirk) Husson, Ioos & Marçais (Husson et al. 2015)

 

Common Name: 

Alder dieback, alder decline

Native To: 

First identified in Europe (Aguayo et al. 2013)

Date of U.S. Introduction: 

Not introduced

Means of Introduction: 

European introductions occurred through infected nursery stock (Adams et al. 2008)

Impact: 

Infects and kills alder trees (trees of the genus Alnus) (Gibbs et al. 1999)

Current U.S. Distribution: 
Not currently established

Spotlights

Announcing IDphy: A Tool for Phytophthora Identification (Sep 30, 2019)

USDA. APHIS. PPQ. CPHST. Identification Technology Program.

ITP and the APHIS PPQ S&T Beltsville Lab are pleased to announce the release of IDphy: Molecular and Morphological Identification of Phytopthora Based on the Types, ITP’s first pathogen tool. This website offers PPQ and its partners the most complete, valid, and up-to-date resource for identifying the culturable species of Phytophthora. IDphy includes detailed standard operating procedures for all steps involved in culturing, sequencing, and identifying suspect samples, covering both molecular and morphological methods. Some species of Phytophthora are devastating plant pathogens that have a significant impact on agriculture and natural ecosystems.

Distribution / Maps / Survey Status

Pest Tracker - Survey Status of Alder Root and Collar Rot

USDA. APHIS. Cooperative Agricultural Pest Survey. National Agricultural Pest Information System.

Federally Regulated

Federal Import Orders

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.

Images

Google Images - Alder Dieback
Google.
Invasive.org - Phytophthora Disease of Alders
University of Georgia. Center for Invasive Species and Ecosystem Health.

Videos

YouTube - Phytophthora alni - An Invasive Species That Attacks Alders

Google. YouTube; Swedish University of Agricultural Sciences. Department of Forest Mycology and Plant Pathology.

Selected Resources

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.

Partnership
Gallery of Pests - Alder Dieback
Nature Conservancy. Don't Move Firewood.
IDphy - Phytophthora × alni

USDA. APHIS. PPQ. CPHST. Identification Technology Program.

Invasive Species Compendium - Phytophthora alni species complex

CAB International.

International Government
Tools & Resources - Phytophthora Disease of Alder

Forestry Commission (United Kingdom). Forest Research.

Citations