1. STAGE 1: INITIATING THE PRA PROCESS
There are generally two initiation points for a PRA (Fig. 1):
- the identification of a pest that may qualify as a quarantine pest.
Either can involve pests already present in the PRA area but not widely distributed and being officially controlled, as well as pests absent from the PRA area, since both are covered by the quarantine pest definition.
1.1 PRA initiated by a pathway
A requirement for a new or revised PRA originating from a specific pathway will most frequently arise in the following situations:
- New plant species are imported for selection and scientific research purposes.
- A pathway other than commodity import is identified (natural spread, mail, garbage, passenger's baggage etc.).
- A policy decision is taken to establish or revise phytosanitary regulations or requirements concerning specific commodities.
- A new treatment, system or process, or new information impacts on an earlier decision.
The pests which are likely to follow the pathway (e.g. be carried by the commodity) are then listed, and each is then subjected to Stage 2 in the PRA process'. If no potential quarantine pests are identified as likely to follow the pathway, the PRA stops at this point.
1.2 PRA initiated by a pest
A requirement for a new or revised PRA originating from a specific pest will most frequently arise in the following situations:
- An emergency arises on interception of a new pest on an imported commodity.
- A new pest risk is identified by scientific research.
- A pest is introduced into a new area other than the PRA area.
- A pest is reported to be more damaging in a new area other than the PRA area itself, than in its area of origin.
- Audits reveal that a particular pest is repeatedly intercepted.
- A request is made to import, as such, an organism, for example by researchers, educators, biological practitioners, businesses (pet store owners), the food industry (snails for consumption) or hobbyists (aquatic plants for aquaria).
- A policy decision is taken to revise phytosanitary regulations or requirements concerning specific pests.
- A proposal is made by another country or by an international organization (RPPO), FAO).
- A new treatment system, process, or new information impacts on an earlier decision.
The specific pest identified is then subjected to Stage 2 in the PRA process.
1.3 Review of earlier PRAs
Prior to proceeding with a new PRA, a check should be made as to whether the pathway or pest has already been subjected to the PRA process, either nationally or internationally. If a PRA exists, its validity should be checked as circumstances may have changed. The possibility of using a PRA from a similar pathway or pest, that may partly or entirely replace the need for this PRA, should also be investigated.
1.4 Conclusion for Stage 1
At the end of Stage 1, pests have been identified as potential quarantine pests, individually or in association with a pathway.
2. STAGE 2: PEST RISK ASSESSMENT
Stage 1 has identified a pest, or list of pests (in the case of initiation by a pathway), to be subjected to risk assessment. Stage 2 considers these pests individually (Fig. 2). It examines, for each, whether the criteria for quarantine pest status are satisfied:
In this context, "area" should be understood to mean:
"an area where ecological factors favour the establishment of a pest whose presence in the area will result in economically important loss"
In doing so, the PRA considers all aspects of each pest and in particular actual information about its geographical distribution, biology and economic importance. Expert judgement is then used to assess the establishment, spread and economic importance potential in the PRA area. Finally, the potential for introduction into the PRA area is characterized.
In characterizing the risk, the amount of information available will vary with each pest and the sophistication of the assessment will vary with available tools. For example, one country may have elaborate pest databases and geographical information systems, another may depend on books, printed soil maps, and climate maps. In some cases, virtually no information may be available, or research may be needed to obtain it. Assessments will be limited by the amount of information available on the biology of a particular pest. Countries where the pest is present may provide available information for the country conducting the PRA, on request.
2.1 Geographical and regulatory criteria
For each pest subjected to the PRA process, the geographical and regulatory criteria in the quarantine pest definition should be considered:
- If the pest is present in the PRA area and has not reached the limits of its ecological range (i.e. not widely distributed), and the pest is subject to official control in the PRA area, then the pest satisfies this aspect of the definition of a quarantine pest.
- If the pest is not widely distributed but is under consideration of future official control in the PRA area, then the PRA will determine whether the pest should be placed under official control. If the conclusion is reached that the pest should be subject to official control, then the pest satisfies this aspect of the definition of the definition of a quarantine pest.
- If the pest is not widely distributed but is not subject to official control or consideration of future official control in the PRA area, then the pest does not satisfy the definition of a quarantine pest and the PRA for the pest stops at this point.
- If the pest is absent from the PRA area, then it satisfies this aspect of the definition of a quarantine pest.
2.2 Economic importance criteria
For potential economic importance to be expressed, a pest must become established and spread. Thus the risk of a pest, having entered, becoming established and spreading in the PRA area must be characterized. The factors to be considered are set out below.
2.2.1 Establishment potential
In order to estimate the establishment potential of a pest, reliable biological information (life cycle, host range, epidemiology, survival etc.) should be obtained from the areas where the pest currently occurs.
The situation in the PRA area can then be carefully compared with that in the areas where it currently occurs and expert judgement used to assess the establishment potential. Case histories concerning comparable pests can usefully be considered. Examples of the factors to consider are:
If a pest has no potential for establishment in the PRA area, then it does not satisfy the definition of a quarantine pest and the PRA for the pest stops at this point.
2.2.2 Spread potential after establishment
In order to estimate spread potential of the pest, reliable, biological information should be obtained from areas where the pest currently occurs.
The situation in the PRA area can then be carefully compared with that in the areas where the pest currently occurs and expert judgement used to assess the spread potential. Case histories concerning comparable pests can usefully be considered. Examples of the factors to consider are:
The information on spread potential is used to estimate how rapidly a pest's potential economic importance may be expressed within the PRA area. This also has significance if the pest is liable to enter and establish in an area of low potential economic importance and then spread to an area of high potential economic importance. In addition it may be important in the risk management stage (Figure 3) when considering the ease with which an introduced pest could be contained or eradicated.
2.2.3 Potential economic importance
The next step in the PRA process is to determine whether the pest is of potential economic importance in the PRA area.
In order to estimate the potential economic importance of the pest, information should be obtained from areas where the pest currently occurs. For each of these areas, note whether the pest causes major, minor or no damage. Note whether the pest causes damage frequently or infrequently. Relate this, if possible, to biotic and abiotic effects, particularly climate.
The situation in the PRA area can then be carefully compared with that in the areas where the pest currently occurs. Case histories concerning comparable pests can usefully be considered. Expert judgement is then used to assess the potential for economic importance. Examples of the factors to consider are:
If a pest has no potential economic importance in the PRA area, then it does not satisfy the definition of a quarantine pest and the PRA for the pest stops at this point.
2.3 Introduction potential
The final stage of assessment concerns the introduction potential which depends on the pathways from the exporting country to the destination, and the frequency and quantity of pests associated with them. Documented pathways for the pest to enter new areas should be noted. Potential pathways which may not currently exist should be assessed if known.
The following is a partial checklist that may be used to estimate the introduction potential divided into those factors which may affect the likelihood of entry and those factors which may affect the likelihood of establishment.
2.4 Conclusion for Stage 2
If the pest satisfies the definition of a quarantine pest, expert judgement should be used to review the information collected during Stage 2 to decide whether the pest has sufficient economic importance and introduction potential, i.e. sufficient risk, for phytosanitary measures to be justified. If so, proceed to stage 3; if not, the PRA for the pest stops at this joint.
3. STAGE 3: PEST RISK MANAGEMENT
Pest risk management (Fig. 3) to protect the endangered areas should be proportional to the risk identified in the pest risk assessment. In most respects it can be based on the information gathered in the pest risk assessment. Phytosanitary measures should be applied to the minimum area necessary for the effective protection of the endangered area.
3.1 Risk management options
A list of options for reducing risks to an acceptable level should be assembled. These options will primarily concern pathways and in particular the conditions for permitting entry of commodities. Examples of the options to consider are:
They may also, however, concern ways of reducing the risk of damage, for example, introduction of a biological control agent, or ease of eradication or containment.
3.2 Efficacy and impact of the options
The efficacy and impact of the various options in reducing risk to an acceptable level should be evaluated, in terms of the following factors:
The positive and negative aspects of the options should be specified. While it is recognized that countries according to the sovereignty principle may exercise their sovereign right to utilize phytosanitary measures, countries should also take particular note of the "Minimal impact" Principle: Phytosanitary measures shall be consistent with the pest risk involved, and shall represent the least restrictive measures available which result in the minimum impediment to the international movement of people, commodities and conveyances. Article VI.2(f) of the International Plant Protection Convention makes a similar but less comprehensive provision. Phytosanitary measures recommended should be based on all of the above factors.
In order to determine which options are appropriate, it may be advisable to communicate with interested and affected groups within and outside the PRA area.
3.3 Conclusion for Stage 3
At the end of Stage 3, the appropriate phytosanitary measures concerning the pest or pathway have been decided. Completion of Stage 3 is essential; it is in particular not justified to complete only Stages 1-2 and then take phytosanitary measures without proper assessment of risk management options. After implementation of the phytosanitary measures, their effectiveness should be monitored and the risk management options should be reviewed, if necessary.
4. DOCUMENTING THE PRA PROCESS
A PRA should be sufficiently documented so that when a review or a dispute arises, the PRA will clearly state the sources of information and the rationales used in reaching a management decision regarding phytosanitary measures taken or to be taken.
G. International standards for phytosanitary measures
Code of conduct for the import and release of exotic biological control agents
ANNEX 2 - DRAFT STANDARD
CODE OF CONDUCT FOR THE IMPORT AND RELEASE OF EXOTIC BIOLOGICAL CONTROL AGENTS
Secretariat of the International Plant Protection Convention of the Food and Agriculture Organization of the United Nations Rome 1995
International Standards for Phytosanitary Measures are subject to periodic review and to amendment.
The next review date is December 1998.
Amendments will be issued as necessary after endorsement by the FAO Conference.
This Reference Standard was endorsed by the 2-th Session of the FAO Conference, 199-.
Food and Agriculture Organization of the United Nations
This Reference Standard has been distributed by the Secretariat of the International Plant Protection Convention to all FAO Members, plus the Executive/Technical Secretariats of the Regional Plant Protection Organizations:
This Reference Standard describes the Code of Conduct for the Import and Release of Exotic Biological Control Agents. It lists the responsibilities of the authorities of governments, and the responsibilities of the exporters and importers of biological control agents.
The Code addresses the importation of exotic biological control agents capable of self- replication (parasitoids, predators, parasites, phytophagous arthropods and pathogens) for research and/or release into the environment including those packaged or formulated as commercial products.
Governments which are already fulfilling the objectives of this Code by regulation or other equivalent means may consider adapting their existing systems in the light of this Code.
Anon, 1988. New organisms in New Zealand. Procedures and legislation for the importation of new organisms into New Zealand and the development, field testing and release of genetically modified organisms. A discussion document. Ministry for the Environment, Wellington, New Zealand, 59 p.
Coulson, J.R. & Soper, R.S. 1989. Protocols for the introduction of biological control agents in the U.S. pp. 1-35. In Plant Protection and Quarantine vol III, Special Topics. R.P. Kahn (Ed.), CRC Press, Boca Raton, Florida.
Coulson, J.R., Soper, R.S. & Williams, D.W. 1992. Proceedings of USDA ARS Workshop on Biological Control Quarantine: Needs and Procedures, 14-17 Jan. 1991, Baltimore, Maryland, Washington, DC, 336 p. US Department of Agriculture, Agricultural Research Service.
EEC. 1991. Official Journal of the European Communities: Council Directive of 15 July 1991.
FAO. 1988. Guidelines on the registration of biological pest control agents. FAO, Rome, 8 p.
FAO. 1990a. Glossary of Phytosanitary Terms. FAO Plant Protection Bulletin, 38(1) :5-23.
FAO. 1990b. International code of conduct on the distribution and use of pesticides; (Amended version). FAO, Rome, 34 p.
FAO, 1995. Guidelines on Pest Risk Analysis, FAO, Rome, 14p. (in preparation)
International Plant Protection Convention. 1992. FAO, Rome, 17p.
Laird, M., Lacey, L.A. & Davidson, E.W. (Eds.) 1990. Safety of microbial insecticides. CRC Press, Boca Raton, Florida, 259 p.
Leppla, N.C. & Ashley, T.R. 1978. Facilities for insect research and production. USDA Technical Bulletin, No. 1576, 86 p.
Lundholm, B. & Stackerud, M. (Eds.) 1980. Environmental protection and biological forms of control of pest organisms. Swedish Natural Science Research Council, Ecological Bulletins, no. 31, 171 p.
NORAGRIC. 1990. Proceedings of the workshop on health and environmental impact of alternative control agents for desert locust control. NORAGRIC Occasional Papers Series C. Development and Environment, no. 5, 114 p.
Waterhouse, D.F.1991. Guidelines for biological control projects in the Pacific. South Pacific Commission Information Document, 57, Noumea, New Caledonia, 30 p.
WHO. 1981. Mammalian safety of microbial agents for vector control: a WHO memorandum. Bulletin of the World Health Organization, 59: 857-863.
3. DEFINITIONS AND ABBREVIATIONS
|Antagonist||An organism (usually pathogen) which does no significant damage to the host but its colonization of the host protects the host from significant subsequent damage by a pest.|
|Area||An officially defined country, part of a country, or all or parts of several countries.|
|Authority||The National Plant Protection Organization (NPPO), or other entity or person officially designated by the Government to deal with matters arising from the responsibilities set forth in the Code.|
|Pest control strategy making use of living natural enemies, antagonists or competitors and other self-replicating biotic entities.|
|A natural enemy, antagonist or competitor, and other self-replicating biotic entity, used for pest control.|
|A generic term, not specifically definable, but generally applied to a biological control agent, usually a pathogen, formulated and applied in a manner similar to a chemical pesticide, and normally used for the rapid reduction of a pest population for short-term pest control.|
|The intentional introduction and permanent establishment of an exotic biological control agent for long-term pest control.|
|Competitor||An organism which competes with pests for essential elements (e.g. food, shelter) in the environment.|
|Ecoarea||An area with similar fauna, flora and climate and hence similar concerns about the introduction of biological control agents.|
|Ecosystem||A complex of organisms and their environment, interacting as a defined ecological unit (natural or modified by human activity, e.g. agroecosystem), irrespective of political boundaries.|
|Establishment (of a biological control agent)||The perpetuation, for the foreseeable future, of a biological control agent within an area after entry.|
|Exotic||Not native to a particular country, ecosystem or ecoarea (applied to organisms intentionally or accidentally introduced as a result of human activities). As this Code is directed at the introduction of biological control agents from one country to another, the term "exotic" is used for organisms not native to a country.|
|Import permit||An official document authorizing importation (of a biological control agent) in accordance with specified requirements.|
|Introduction (of a biological control agent)||The release of a biological control agent into an ecosystem where it did not exist previously (see also "establishment").|
|Inundative release||The release of overwhelming numbers of a mass-produced, invertebrate biological control agents in the expectation of achieving a rapid reduction of a pest population without necessarily achieving continuing impact.|
|Legislation||Any Act, Law, Regulation, Guideline or other administrative order promulgated by a Government.|
|Micro-organism||A protozoan, fungus, bacterium, virus or other microscopic self-replicating biotic entity.|
|The official service established by a Government to discharge the functions specified in the International Plant Protection Convention.|
|Natural enemy||An organism which lives at the expense of another organism and which may help to limit the population of its host. This includes parasitoids, parasites, predators and pathogens.|
|Naturally occurring||A component of an ecosystem or a selection from a wild population, not altered by artificial means.|
|Organism||A biotic entity capable of reproduction or replication; vertebrate or invertebrate animals, plants and micro-organisms.|
|Parasite||An organism which lives on or in a larger organism, feeding upon it.|
|Parasitoid||An insect parasitic only in its immature stages, killing its host in the process of its development, and free living as an adult.|
|Pathogen||Micro-organism causing disease.|
|Pest||Any species, strain or biotype of plant, animal or pathogenic agent, injurious to plants or plant products.|
|Predator||A natural enemy that preys and feeds on other animal organisms, more than one of which are killed during its lifetime.|
|Quarantine (of a biological control agent)||Official confinement of biological control agents subject to phytosanitary regulations for observation and research, or for further inspection and/or testing.|
|Release (into the environment)||Intentional liberation of an organism into the environment (see also, " introduction " and " establishment " ) .|
|Specificity||A measure of the host range of a biological control agent on a scale ranging from an extreme specialist only able to complete development on a single species or strain of its host (monophagous) to a generalist with many hosts ranging over several groups of organisms (polyphagous).|
4. OUTLINE OF CODE
The Code is concerned with the importation of exotic biological control agents capable of self-replication (e.g. parasitoids, predators, parasites, phytophagous arthropods and pathogens) for research, and field release of control agents used in biological control and those used as biological pesticides. Currently used formulations of live pathogens are included because they possess the potential for multiplication and persistence in the environment. Naturally occurring strains (genetically, if not morphologically distinct entities) of natural enemies may show notable differences in specificity and infectivity, for example strains of Bacillus thuringiensis (Bt), and if exotic, fall within the terms of reference of this Code.
It is recognized that it may often be difficult to know whether the agent in a biological pesticide is exotic or not. For that reason many biological pesticides may have to be treated as though they were exotic.
The Code does not deal with other pest control techniques, that are also sometimes referred to as "biological controls", notably, autocidal methods, resistant host plants, as well as behaviour-modifying chemicals and other novel biological products. For toxic products of microbes used as pesticides which cannot reproduce and which are similar to conventional chemical pesticides, refer to the "International Code of Conduct on the Distribution and Use of Pesticides" (FAO, 1990) where they are covered in detail.
Procedures governing the handling and release into the environment of strains of organisms created artificially by genetic engineering are currently being examined by various international organizations and by national programmes. If required this Code could be applied to these organisms.
It is possible that this Code, after due evaluation, could also be applied to the introduction of exotic biological agents to control pests affecting human or animal health or the conservation of natural habitats.
Thus the Code deals with:
It does this by:
- describing three responsibility phases of
the process of import and release: the responsibilities
those involved before export; those before and upon importation; and those after importation.