Purpose and Role of Plant Pest Quarantines

The Minnesota Department of Agriculture (MDA) works to prevent the introduction and spread of destructive invasive species in Minnesota. For some organisms, regulating the movement of certain products or materials can help to prevent introductions and spread.

Quarantines have been used for centuries to contain harmful pests and deadly pathogens.  Plant pest quarantines are imposed to prevent artificial introduction or to limit the spread of agricultural plant pests. Such quarantines may restrict the production, movement or existence of plants, plant products, animals, animal products, or any other articles or material, or activity of people which could result in the artificial introduction or spread of the specified pest(s).

Quarantine and Compliance Agreement Information

Quarantines help prevent potentially dangerous or destructive organisms from spreading into new areas. For example, a quarantine for the emerald ash borer is meant to prevent the movement of infested firewood or ash wood that might harbor emerald ash borer life stages.

When a need exists to move an item that could transport a regulated organism out of a quarantine area a compliance agreement is issued. A compliance agreement describes what steps will be taken by the entity to ensure that the regulated organism is not moved along with the item. A compliance agreement can be obtained through the Minnesota Department of Agriculture or United States Department of Agriculture. Contact the MDA if you need a compliance agreement.

Insects and Pathogens Regulated Under Quarantines in Minnesota

Emerald Ash Borer – a number of counties are quarantined to prevent the spread of EAB within Minnesota, all ash material and hardwood firewood is prohibited from entering Minnesota from other states

Spongy Moth – a number of counties are quarantined to prevent the spread of spongy moth within Minnesota

Mountain Pine Beetle – pine wood with bark from the western U.S. is prohibited from entering Minnesota due to mountain pine beetle

Firewood Information

Firewood is considered to be one of the most prominent ways in which humans assist in spreading invasive pests. It is important to be aware of regulations that affect the movement of firewood.

Minnesota Department of Agriculture’s (MDA) Role

A quarantine is a legal instrument duly imposed or enacted by MDA as a means of mitigating pest risk. A quarantine enables enforcement of prohibitions, restrictions, treatment and certification requirements and other pest risk mitigation or management measures identified as being necessary to prevent the harm or damage that could result from the introduction and permanent establishment of an exotic pest in an endangered area. 

Authority and Preemption

Quarantines are seldom statutory in nature i.e., they are not enacted through the legislative and executive branches of government. Instead, a quarantine is usually in the form of administrative law duly authorized by statute and promulgated as rules or regulations pursuant to a procedure elaborated in statutory law. MDA’s statutory authority is found in §Chapter 18G.06.  Any quarantine not promulgated on the basis of statutory authority is not legally binding and is subject to legal challenge and revocation.

It is generally accepted that federal quarantine law preempts state quarantine requirements. Similarly, local quarantine requirements are preempted by state quarantine requirements.

Principles of Plant Quarantine

The National Plant Board is a non-profit organization of the plant pest regulatory agencies of each of the states and Commonwealth of Puerto Rico.  The principles of plant quarantine elaborated here are a concise restatement of the principles originally adopted by the National Plant Board in the 1930's.   

  1. Inasmuch as the purpose of plant quarantines and the means required to achieve them cannot be undertaken by private individuals or groups, quarantines properly are the responsibility of government.
  2. Quarantines shall not be imposed as trade barriers.
  3. Quarantines will be established on the basis of the following:
    1. As determined by a pest risk assessment, the plant pest targeted must pose an actual or anticipated threat to a substantial agricultural or environmental interest and/or the general public. However, the absence of complete biological knowledge of a pest will not necessarily prohibit the adoption of a quarantine.
    2. No substitute or alternative mitigating action will accomplish the same pest prevention purpose.
    3. Accomplishment of the stated purpose is a reasonable expectation.
    4. Economic and/or environmental benefits outweigh the cost of administration and the costs to those who must comply with the restrictions imposed.
  4. Regulations or rules establishing quarantines will be adopted with input from those interested in and affected by them. The United States Department of Agriculture (USDA) and the states are cooperating agencies which will be involved as appropriate. There also can be international considerations. When foreign trade is involved, states need to work with the USDA to determine which definitions and standards need to be met. Internationally, the International Plant Protection Convention may be involved. Regionally, the North American Plant Protection Organization or other Regional Plant Protection Organizations may be involved.
  5. Quarantines will be as narrow in scope as possible while maximizing the potential for accomplishing their purpose.
    1. Quarantines imposed in connection with plant pest eradication projects may be broader in scope and/or more restrictive because of the importance of the quarantined pest, the prognosis for its eradication or control, and its effects on the environment.
    2. Quarantines imposed to prevent or slow the spread of established pests should be narrow in scope.
  6. Quarantine areas should be as limited as possible and should be consistent with the area known to be infested. Whenever possible, boundaries shall be based upon existing state, county or township lines, major highways or roads, or geographic features such as rivers and mountain ranges.
  7. Quarantines should be written as clearly and concisely as possible.
  8. Adoption of a quarantine against a serious plant pest new to the endangered area will be accompanied by an information campaign. The scope and intensity of this campaign should be in proportion to the economic and/or environmental importance of the pest.
  9. The scope of and restrictions imposed by a quarantine should be reduced or increased based on experience and information obtained in the administration of the quarantine.
  10. Regulations establishing quarantines will be repealed when their purposes have been accomplished.