An official website of the United States government.

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

Alder Dieback

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)


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

Current U.S. Distribution

Not currently established

Phytophthora disease of alders (Alder dieback)

Phytophthora disease of alders (Alder dieback), symptoms


Photo by Andrej Kunca; Slovakia National Forest Centre

Find more images

Distribution / Maps / Survey Status

Federally Regulated

  • Import Federal 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.


Selected Resources

The section below contains highly relevant resources for this species, organized by source.

International Government