California Department of Food and Agriculture - Pest Rating System            

              Rev 07/29/24

I   GENERAL PRINCIPLES

Guidelines for Interpreting, Establishing or Changing Pest Ratings

Plant Health and Pest Prevention Services

California Department of Food and Agriculture

The California Food and Agricultural Code mandates that, the California Department of Food and Agriculture (CDFA) shall prevent the introduction and spread of injurious insect or animal pests, plant diseases, and noxious weeds.  This statutory duty requires a pest policy which recognizes that organisms vary in their potential and actual harm to the agriculture and environment of California.  Overall pest significance is based on the probability of spread of the pest, the potential economic damage, the presence of host species, the favorability of the climate and other factors. Pest ratings are based on that evaluation and provide the basis for determining what pest prevention activities are appropriate, at what level, and when and where those activities should be conducted.

(i)                Pest ratings are intended as aids to inform County Agricultural Commissioners and other interested persons as to a particular pest’s environmental, agricultural and biological significance, as well as its importance to the general public, and the action recommended by the California Department of Food and Agriculture (CDFA) to deal with the pest.

(ii)               Each pest rating represents the view of CDFA of the statewide importance of the pest to the agricultural, horticultural, forestry, and public health interests of California.  Local conditions may dictate more stringent action against the same pest in individual counties at the discretion of the County Agricultural Commissioner.

(iii)               It is the policy of CDFA to use an Action-Oriented Rating System.�  Pest ratings represent the policy of CDFA in relation to actions to be taken, consistent with existing statutes, which include authority for: the promulgation of quarantine, eradication, control, standards of cleanliness, and other regulations; holding and inspection; establishing host-free, weed-free, and special pest control districts; and for other regulatory activities.

II  ACTION-ORIENTED RATING SYSTEM

DEFINITIONS

A    An organism of known economic importance subject to action enforced by the state (or County Agricultural Commissioner acting as a state agent) involving:  eradication, quarantine regulation, containment, rejection, or other holding action.

Q     An organism or disorder requiring a temporary A� action pending determination of a permanent rating.  The organism is suspected to be of economic importance but its status is uncertain because of incomplete identification or inadequate information.  In the case of an established infestation, at the discretion of the Director, CDFA may conduct surveys and may convene the Division Pest Study Team to determine a permanent rating.

B      An organism of known economic importance that is of limited distribution in the State of California and is subject to:  eradication, containment, control or other holding action at the discretion of the individual County Agricultural Commissioner. Or, an organism of known economic importance subject to state endorsed holding action and eradication only when found in a nursery.

C     An organism already of common occurrence in the state that is subject to no state-enforced action outside of nurseries except to retard spread.  At the discretion of the County Agricultural Commissioner. Or, an organism subject to no state enforced action except to provide for pest cleanliness in nurseries.

D      No Action - plant parasites or other organisms of little or no economic importance, or organisms considered beneficial..

Newly detected pest species are subjected to a formal rating process that allows input from stakeholders and requires regular review of their status in the State.  Greater detail on the pest rating system and the mitigating actions triggered by detection of a pest in each of the ratings is available at:

https://www.cdfa.ca.gov/plant/pestratings/docs/3162-ApprovedText-final.pdf

Details of the Pest Rating System in California are provided at:

https://www.cdfa.ca.gov/plant/regs_pestrating.html

 III  PEST RATINGS FOR NEMATODES IN CALIFORNIA

Pest Ratings are under frequent review and subjact to change as new information becomes available and new pests are detected.  The most current list for nematodes is available at:

http://blogs.cdfa.ca.gov/Section3162/?p=1955

As of July 2024, nematode pest ratings for the State of California are listed below with links to greater information on the biology and management of the pest.

Nematode Pest Rating List - July 2024

(Alphabetically by genus and species)

Nematode Pest Rating List, July 2024

(sorted by rating)

Nematode Pest Rating List, Previous version (Prior to 2021)

(sorted by rating)

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