NEPDN Plant Diseases




Thousand Cankers Disease has Been Confirmed in Pennsylvania

Thousand cankers disease (TCD) was recently detected on black walnut in eastern Pennsylvania, in Bucks county north of Philadelphia. The Pennsylvania Department of Agriculture has enacted a quarantine and a delimit survey has begun. More information is available on the Pennsylvania Department of Agriculture website.
This means TCD has now been confirmed in three eastern states within the native range of black walnut (TN, VA and PA) as well as nine western states.  
Please do a visual survey of your trees and trees in your community and notify state authorities of any unusual wilting and yellowing or dying walnut trees.

Select Agents

What is a select agent?

Certain pathogens are assigned the distinction of select agent as part of the Agricultural Bioterrorism Protection Act of 2002. This act is a subpart of the Public Health Security and Bioterrorism Preparedness Response Act of 2002, which was signed into law by the President on June 12, 2002. The act require that entities, such as private, State, and Federal research laboratories, universities, and vaccine companies, that possess, use, or transfer agents or toxins deemed a threat to public health or animal or plant health or products register these agents with the appropriate Federal Department.

Select agents are chosen based on several criteria. First they were chosen on how easily they are dispersed. Second, they were also chosen based on the availability of methods to manage and prevent the disease. Third they were chosen based on the virulence of the pathogen and its effect on a host. The select agent list is not static. As different agents enter the United States the list should change over time. In March 2005, two select agents that cause Plum pox and Soybean rust were removed from the original select agent list.

Common Name Scientific Name
Red Leaf Blotch Phoma glycinicola
Gumming Disease in Ryegrass Rathayibacter toxicus
Philippine Downy Mildew Peronosclerospora philippinensis
Sugarcane Downy Mildew Peronoclerospoora saccari
Bacterial Wilt/Brown Rot Ralstonia solanacearum Race 3 Biovar 2
Brown Stripe Downy Mildew Sclerophthora sayssiae var. zeae
Potato Wart Synchyrtium endobioticum
Bacterial Leaf Streak Xanthomonas oryzae
Citrus Variegated Chlorosis Xylella fastidiosa

Significant Pathogens

Common Name Scientific Name
Chrysanthemum White Rust Puccinia horiana
Citrus Greening Liberobacter africanus, Liberobacter asiaticus
Hosta Virus X  
Karnal Bunt Tilletia indica
Plum Pox Plum Pox Potyvirus
Soybean Rust Phakopsora pachyrhizi
Sudden Oak Death/Ramorum Blight Phytophora ramorum
Thousand Cankers Disease Geosmithia morbida


NEPDN - Significant Agent Listing


Significant Agents are defined as plant pathogens, insects, nematodes, and weeds deemed hazardous to our regional agricultural and natural ecosystems. Although many of these organisms are established in the United States, they have the potential to cause significant damage in the Northeast Region.

We wish to identify these pathogens and pests so that we can provide members of the network with timely information about their presence or spread within the Northeast.  When an identification of one of the following organisms is made, diagnosticians will notify other regional network members, via the regional list-serve, of the finding. Regions will compile electronic fact sheets and informational websites and link them to their regional websites.

To keep the list manageable we hope to limit it to 20-30 agents. Organisms already on the Agricultural Bioterrorism Select Agent listing need not be included on this listing.  

* after the name means it is a Federally Regulated Organism.


  1. Thousand Cankers, Geosmithia morbida
  2. Bacterial ring rot/ canker, Clavibacter michiganensis subsp. michiganensis
  3. Golden Nematode, Globodera rostochensis *
  4. Potato Mop Top, Mop Top Virus *
  5. Sudden Oak Death/Ramorum Blight, Phytophthora ramorum *
  6. Chrysanthemum White Rust, Puccinia horiana *
  7. Karnal Bunt, Tilletia indica *
  8. Soybean Rust, Phakopsora pachyrhizi *
  9. Plum Pox, Plum Pox Virus *
  10. Late Blight, Phytophthora infestans


  11. Emerald Ash Borer, Agrilus planipennis *
  12. Asian Longhorned Beetle, Anoplophora glabripennis *
  13. Brown marmorated stink bug, Halyomorpha halys
  14. Bemisia tabaci biotype Q
  15. Winter Moth, Operophtera brumata
  16. Sirex Wood Wasp, Sirex noctilio
  17. Swede Midge
  18. European Crane Flies
  19. Asian Gypsy Moth
  20. Leek Moth, Acrolepiopsis assectella
  21. SpottedWing Drosophila, Drosophila suzukii


  22. Giant Hogweed, Heracleum mantegazzianum *
  23. Black Swallowwort, Cynanchum nigrum
  24. Water Chestnut, Trapa natans
  25. Japanese Stilt Grass, Microstegium vimineum
  26. Mile-a-minute, Polygonium perfoliatum

03/28/11 klsc

NEPDN Significant Agents in PDF format 03-28-11