Species Profiles - Plant Pathogens
Some introduced plant pathogens have become established throughout Pennsylvania such as Chestnut blight (American chestnut), and Dutch elm disease (American elm) which have vastly changed the composition of our North American forests. Others remain outside our borders, held at bay principally by regulatory restrictions on movement of plant material and by certification programs in major crop systems and in nursery stock. Since a plant pathogen may well be impossible to detect with visual inspection, it is very difficult to stop all movement of plant pathogens without stopping all movement of plants and plant parts, making regulatory programs vital. A certification program of best practices and testing for disease-free seed keeps pathogens such as ring rot or potato wart from destroying our potato industry. The stone fruit industry relies on import restrictions that keep plum pox or European stone fruit yellows from impacting the largest part of the U.S. fruit industry. Eradication of plum pox virus has cost federal and state governments over 40 million dollars in the first six years of the program – it has cost Pennsylvania fruit growers far more, seriously affecting their livelihoods. Yet the program is succeeding in keeping the disease from spreading to more orchards. [Revised 4/10/2008]
Note: The table below contains examples of Plant Pathogens with invasive characteristics that are of concern in the
World, the Nation, or in the Commonwealth.  Please check the Pennsylvania Department of Agriculture website
for current information on the regulatory status of any of these species in Pennsylvania. 

Bacteria and Viruses
Sudden Oak Death/Ramorum Blight
  • Organisms listed above are just some of the species that were mentioned in the various Council documents published in 2006 and this is not a comprehensive list of invasive species in this group for Pennsylvania.

  • Whenever possible, we have linked to a Pennsylvania specific fact sheet or a federal fact sheet.

For more information on Invasive Species of National concern visit:
National Invasive Species Information Center website. See the Dichotomous Key beginning on page (v.) and the Appendix C-Insect, Pathogen & Abiotic Advisories beginning on page (75.) of the National Park Service Forest Insect Disease Rapid Response Plan.

 Explore The Species Profiles: