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PPDC Nematology lab

Plant Pest Diagnostics Center - Nematology Laboratory

CDFA Pest Ratings for Plant Parasitic Nematodes

For an up-to-date listing of ratings for plant parasitic nematodes please click on the following link: Pest Ratings Nematodes

California Code of Regulations Title3, Division 4, Chapter 3, Section 3162. Pest Ratings and Mitigating Actions provides details related to definitions and requirements. Click the following link to view the regulation: Section 3162 (pdf)

Definitions of pest ratings included in regulations and used for plant parasitic nematode species are:

  • A” rating is for pests of the agricultural industry or environment which score high and are not known to occur or under official control in the State of California.
  • B” rating is for pests of the agricultural industry or environment which score medium to high and which are of limited distribution in the State of California.
  • “C” rating is for pests of the agricultural industry or environment which score medium to low and are of common occurrence and generally distributed in California.
  • “D” rating is for an organism which scores low and is known to be of little or no economic importance to the agricultural industry or environmental detriment, has an extremely low likelihood of invasiveness, is known to be a parasite or predator or pathogen of a pest, or is an otherwise beneficial organism.
  • “Q” rating is for pests of the agricultural industry or environment which score high and which are not known to occur or where their California distribution is unknown and which are otherwise suspected of being economically harmful to the agricultural industry or the environment and which may not be completely identified or for which there is inadequate scientific information.