About Widely Prevalent Plant-Parasitic Nematodes of the United States

The Widely Prevalent Plant-Parasitic Nematode List is periodically updated by regional coordinators working in collaboration with plant pathology personnel designated by the state department of agriculture in each state.

A "Widely Prevalent" organism is defined by the WPNL working group as an organism that:

  • is widely distributed in any given five year period in the State where the host plant(s) is grown. It does not have to be encountered every year at every location
  • would raise no new regulatory concerns at the State or Federal level if it was identified

The Widely Prevalent Plant-Parasitic Nematode list is made available for the use of nematologists, plant pathologists, educators, and others interested in nematodes. The development of the list for each state relies on the expertise and knowledge of Cooperative Extension personnel, plant pathologists, scientific publications, and other information accumulated over a number of years, in collaboration with State Plant Regulatory Officers The list is not necessarily conclusive nor complete, and thus, it should not be used as a source of information for legal purposes. Nematode species may be added or deleted as scientific expertise on distribution of such species, taxonomic status, and other conditions change over time.

PLEASE NOTE: a permit is still required in order to bring the organism into your state, even though it may be listed in this database.

The database is used by the Animal Plant Health Inspection Service, Plant Protection Quarantine (APHIS-PPQ) and State Plant Regulatory Officials to develop a list of plant-parasitic nematodes that are common in each state to help expedite the permitting process for obtaining research isolates. The list of nematodes that are candidates for expedited permitting in a given state are available on the APHIS-PPQ Expedited Permit list. Even though a pathogen/parasite is on the widely prevalent list, it is NOT necessarily on the expedited permit list. The APHIS-PPQ Expedited Permit list is available on the APHIS website, along with standard permit conditions.

Regional Coordinators

Other Widely Prevalent Sites