RMD-16-01: Pest Risk Management Document – Determining the regulatory status of Rhagoletis pomonella (apple maggot)

Effective date: April 1, 2017

Original

Preface

As described by the International Plant Protection Convention (IPPC), Pest Risk Analysis (PRA) includes three stages: initiation, pest risk assessment and pest risk management. Initiating the PRA process involves identifying pests and pathways of concern and defining the PRA area. Pest risk assessment provides the scientific basis for the overall management of risk. Pest risk management is the process of identifying and evaluating potential mitigation measures which may be applied to reduce the identified pest risk to acceptable levels and selecting appropriate measures.

This Risk Management Document (RMD) includes a summary of the findings of a pest risk assessment and records the pest risk management process for the identified issue. It is consistent with the principles, terminology and guidelines provided in the IPPC standards for pest risk analysis which may be found at the International Plant Protection Convention website.

Table of contents

1.0 Executive summary

Rhagoletis pomonella (Walsh), apple maggot, is indigenous to eastern North America and a regulated pest in Canada. The main hosts of R. pomonella are apples and crabapples (Malus spp.) and hawthorn (Crataegus spp.). In 2006, apple maggot was detected for the first time in western Canada. This insect is considered to have a limited distribution in British Columbia (B.C.). To prevent the introduction and spread of apple maggot into and within B.C., the Canadian Food Inspection Agency (CFIA) regulates the importation and domestic movement of regulated articles, including: fresh fruit and plants with roots of host species; used apple containers; and soil.

Although R. pomonella is present in most regions of Canada, it is not present in the southern interior of B.C. This important fruit-growing region has been identified as a pest free area (PFA). The CFIA carries out annual specific surveillance in the PFA to verify pest freedom. If one or more R. pomonella adults are detected within the PFA, the CFIA will implement official measures to control and/or reduce potential spread of the pest and will carry out additional surveillance to determine whether the insect is present and if so, to delimit its distribution. The CFIA will consider R. pomonella to be present in an area when both adult flies and larvae are detected.

If R. pomonella is found to be present in the PFA or in a specific area within the PFA, the CFIA will notify industry stakeholders and government partners in B.C. and will issue an official pest report to notify trading partners. The CFIA will take into account specific information related to the detection and the biology of the insect when making a decision on appropriate regulatory measures and next steps. Other relevant factors, such as the costs and benefits of regulating R. pomonella , and the technical and logistical ability to control or eradicate it within the specific area where it has been found, will also be taken into consideration. Depending on the circumstances, it may be possible to change the boundaries of the PFA to exclude the infested area or to regulate a specific area within the PFA.

The CFIA intends to maintain the PFA, apply official control measures and regulate R. pomonella until such time as it decides to deregulate this pest. The CFIA will deregulate R. pomonella if the pest is found to be present in the PFA but official control measures are not implemented, or if this insect is found to be established and widespread in the PFA. The CFIA will then be obligated to take steps to remove this insect from the List of Pests Regulated by Canada and revoke the import and domestic movement requirements related to R. pomonella .

2.0 Purpose

This Risk Management Document (RMD) describes the regulatory steps that the CFIA will follow when responding to detections of R. pomonella in the PFA in B.C.

3.0 Scope

This RMD provides guidelines for evaluating the pest status of R. pomonella in the PFA in B.C. It also describes the conditions for maintaining the PFA, changing the boundaries of the PFA and removing the PFA designation. This document will assist in future decision-making with respect to evaluating the presence/absence and distribution of this insect within the PFA. This RMD is also intended to explain the steps that the CFIA would take should the status of R. pomonella change from a regulated pest that falls under the CFIA's authority under the Plant Protection Act to an economic pest managed by industry at the orchard level.

4.0 Definitions, abbreviations and acronyms

Definitions of terms used in this document can be found in the Plant Health Glossary of Terms or the Phytosanitary Glossary within the FAO Term Portal.

5.0 Background

Rhagoletis pomonella , apple maggot, is indigenous to eastern North America and is a pest of apples in Canada. The first record of R. pomonella attacking apples in Canada was in Ontario, in 1896. Rhagoletis pomonella is widespread throughout eastern Canada and was found to be established in Edmonton, Alberta and the Lower Mainland, Fraser Valley, and Vancouver Island in B.C. in 2006. In 2013, R. pomonella was also confirmed to be present in Prince George, B.C. Additional information on the biology of this insect is available in the CFIA's Apple Maggot Fact Sheet.

The Okanagan, Similkameen and Creston Valleys in the southern interior of B.C. are the last major apple-growing areas in North America that are free of this pest. Based on official surveys, these valleys have been designated as a PFA with respect to R.  pomonella. These interior fruit-producing regions are surrounded by steep mountain ranges and are geographically isolated from known R. pomonella populations in Canada. The most likely pathways for the movement of R. pomonella into the interior fruit-producing valleys of B.C. are human-assisted spread from established populations in North America or natural spread from adjacent infested areas.

The domestic movement of regulated articles, such as apple and hawthorn fruit, host taxa nursery stock, used containers and soil from infested areas into B.C., is regulated under the Plant Protection Regulations . The CFIA's Plant Protection Directive D-00-07: Phytosanitary requirements to prevent the introduction and spread of apple maggot, Rhagoletis pomonella [Walsh] describes the phytosanitary requirements that are in place to mitigate the risk associated with domestic movement and importation of regulated articles from areas that are infested with R. pomonella into the province of B.C. and domestic movement from regulated areas within B.C. into the PFA.

If R. pomonella were to establish in the commercial fruit-growing regions in the southern interior of B.C., it would likely result in an increase in pesticide and pest management costs and could also impact the sustainability of the area-wide codling moth sterile insect release (SIR) program. Apples produced in B.C. are exported to some markets based on originating in an area that is free of R. pomonella . If this insect establishes in the commercial apple production regions of the southern interior of B.C., the CFIA will notify its trading partners and some of these countries may change their phytosanitary import requirements for apples produced in B.C.

6.0 Current pest status

The status of R. pomonella in Canada is "Present: except in specified pest free areas". As per International Standard for Phytosanitary Measures (ISPM) 8, a pest is considered to be present in an area if records indicate that it is either indigenous (e.g. R. pomonella in eastern Canada) or introduced (e.g. R. pomonella in the Fraser Valley, B.C.).

Rhagoletis pomonella is a quarantine pest of Canada. Its movement is restricted in Canada as specified in Schedule II of the Plant Protection Regulations and the movement of regulated articles is governed by directive D-00-07. The CFIA has surveyed for R. pomonella in B.C. on an annual basis for several decades. The purpose of these detection surveys is to verify the pest-free status of the areas being surveyed and to detect new pest incursions.

The PFA includes significant commercial tree fruit production areas in the southern interior of B.C. The CFIA carries out detection and delimitation surveys within the PFA to establish pest freedom and to verify that freedom is maintained. The CFIA also regulates the movement of regulated articles from infested areas to the uninfested area, to prevent spread of the pest. The areas adjacent to the PFA are not known to be infested.

The 8th revision of directive D-00-07 establishes a PFA for R. pomonella in the southern interior of the province of B.C. Appendix 1 of D-00-07 includes a map and the list of the regional districts and electoral areas that make up the PFA.

7.0 Determining the pest status of Rhagoletis pomonella

Official CFIA surveys targeting R. pomonella continue to be used to verify the status of this insect within the PFA. The CFIA also considers data from general surveillance, although it may be necessary to independently verify this information, at the CFIA's discretion. General surveillance includes data obtained from other federal departments, provincial government departments, research institutions, universities, producers, consultants and the general public.

The CFIA categorizes the status of R. pomonella within an area as either absent, transient or present, based on official survey results. As per ISPM 8: Determination of pest status in an area, these pest status categorizations may be further characterized to clarify the regulatory status and/or distribution of the insect.

A. Absent

Rhagoletis pomonella is considered absent in areas where no adult female R. pomonella flies or R. pomonella larvae have been detected (ISPM 26: Establishment of pest free areas for fruit flies [Tephritidae]).

B. Transient

If one or more adult female R. pomonella are detected in an area, but no Rhagoletis spp. larvae are found in apple or hawthorn fruit within 800 metres of an adult detection, R. pomonella will be considered transient. An area may be returned to absent status if official CFIA surveys are carried out and no R. pomonella is detected in the area.

C. Present

Rhagoletis pomonella will be considered present in an area if two different life stages of R. pomonella are detected within a distance of 800 metres of each other during the same calendar year. In other words, if one or more adult female R.  pomonella are caught on a trap and one or more Rhagoletis spp. larvae are found in an apple or hawthorn fruit within 800 metres of the positive trap in the same calendar year, the CFIA will consider the pest to be introduced to that area. An area may be returned to absent status if official CFIA surveys find no R. pomonella in the area for a minimum of three consecutive years.

8.0 CFIA regulatory tools and international obligations

A. Phytosanitary measures

As per Plant Protection Directive D-00-07, the CFIA restricts the movement of regulated articles, including fresh apple, crabapple and hawthorn fruit; apple, crabapple, hawthorn and cherry trees; used apple containers; and soil. The directive describes the phytosanitary requirements that are in place to mitigate the risk associated with domestic movement and importation of regulated articles from areas in North America that are infested with R. pomonella into the province of B.C., and domestic movement from regulated areas within B.C. to areas of B.C. where R. pomonella does not occur.

B. Detection surveys

The CFIA carries out an annual detection survey for R. pomonella within the PFA. The purpose of these detection surveys is to verify the pest-free status of the PFA and to facilitate early detection of R. pomonella should it be introduced to the PFA.

C. Official control measures

Any change to the status and distribution of R. pomonella in the southern interior of B.C. will trigger regulatory actions by the CFIA, at least in the short term. If R. pomonella is detected within the boundaries of the PFA, the CFIA will respond by putting official control measures in place to restrict the movement of regulated articles in order to minimize the risk of further spread of this insect within the PFA. Official control measures will remain in place until delimitation surveys are completed, survey results are reviewed, and risk management decisions are made regarding next steps and the longer term regulatory status of this pest.

Official control measures are intended to mitigate the risk of human-assisted spread of the pest. They may include measures to restrict the movement of regulated articles from the area where the pest was detected and measures to reduce pest populations. Official control measures may include one or more of the following:

  • Notifying regulated parties, government partners and industry stakeholders;
  • Applying official control measures to prevent human-assisted spread of R. pomonella into the PFA from the new infested area;
  • Ensuring that regulated articles destined for disposal are handled appropriately;
  • Considering options for suppressing or eradicating the pest population (e.g. removal of host trees, removal of fruit, application of pesticides); and
  • Implementing these activities in partnerships with industry stakeholders and other government departments, as appropriate.

D. Delimitation surveys

A delimitation survey is conducted to establish the boundaries of an area where a pest has been detected. The detection of even a single R. pomonella in the PFA will trigger a delimitation survey. Additional traps may be placed in the vicinity of the positive trap(s) either during the current year or the following year, depending on the date of the detection. Fruit in and around the positive tree(s) will also be visually inspected for the presence of R. pomonella fruit damage and larvae.

Delimitation surveys may continue for three years, or more, following the initial detection of R. pomonella in an area. If there are no further detections of R. pomonella in the vicinity of the original detection for three consecutive years, the pest will be considered absent. Additional detections of adult female R. pomonella will trigger additional delimitation surveys. If one or more Rhagoletis spp. larvae are found in apple or hawthorn fruit within 800 metres of an R. pomonella adult detection site in the same calendar year, R. pomonella will be considered present and the area will be subject to additional surveillance and official control, as appropriate.

Delimitation surveys may indicate that there is an isolated population of R. pomonella in the PFA and that this population may establish unless appropriate phytosanitary measures are applied to eradicate it. The CFIA will only consider applying phytosanitary measures for eradication in situations where the R. pomonella population is very small and has a very restricted distribution. Furthermore, an eradication program would only be initiated if it had a very high likelihood of success, if the benefits of eradication outweighed the costs and if the eradication program was supported by industry. Official control measures and annual surveillance will continue in any area that is under eradication until the pest can be considered absent or until the eradication program is ended. Additional detections of R. pomonella in the area under eradication may trigger additional delimitation surveys and a re-evaluation of official control measures and regulatory options.

E. International obligations

In compliance with international standards, if R. pomonella is found to be present in the PFA (Section 7.0) or in a specific area within the PFA, the CFIA will issue an official pest report to notify trading partners. The CFIA will also be required to take one of the following actions: regulate any infested areas that are identified within the PFA; change the boundaries of the PFA to exclude the infested area(s); or deregulate R. pomonella and dissolve the PFA.

9.0 CFIA course of action

Scenario 1: Maintain the PFA for R. pomonella

The CFIA will continue to carry out annual surveys for R. pomonella , according to the CFIA's survey plan for this insect. The boundaries of the PFA will remain unchanged as long as R.  pomonella is absent from the area or transient and under official control. Risk mitigation measures will continue to be required when regulated articles are moved into the PFA.

Scenario 2: Modify the boundaries of the PFA for R. pomonella or regulate an infested area within the PFA

If R. pomonella is introduced to the PFA, the CFIA will have to decide whether to continue applying official control measures to the infested area or whether to modify the PFA, taking into account relevant factors such as the costs and benefits of regulating R. pomonella , and the technical and logistical ability to control it within the defined area. If a pest is present, but not subjected to official control, then it no longer qualifies as a quarantine pest.

If R. pomonella is found to be present in the PFA and eradication is not considered feasible,the CFIA will consider longer term regulatory options, such as continued regulation of the infested area within the PFA or modification of the boundaries of the PFA. If the latter is chosen, the CFIA will consider what the boundaries of the revised regulated area should be. Additional surveys would be required to delimit the infestation and assess the population level. The boundaries of the R. pomonella infested area would be defined based on an assessment of risk factors, including proximity to the infestation, host distribution, geography and land use.

The CFIA will consult with government and industry stakeholders to determine the appropriate decision for the particular circumstance. The regulatory measures will be extended, expanded or removed, as appropriate, depending on these decisions. Regulatory decisions will consider a number of factors, including:

  • R. pomonella survey data;
  • R. pomonella biology and life history;
  • The presence and distribution of R. pomonella host plants in the vicinity of the detection;
  • The size and location of the infested area relative to the boundaries of the PFA;
  • Land use and whether the infested area includes residential areas, commercial orchards, production nurseries or retail nurseries;
  • Land ownership (private, municipal, federal, First Nations, etc.);
  • Partnerships with industry stakeholders and other government departments;
  • The technical and logistical feasibility of applying required official control measures;
  • The consequences of regulatory action on impacted stakeholders; and
  • The costs and benefits of maintaining the PFA.

Modifying the boundaries of the PFA will include the following steps:

  • Consulting the British Columbia Plant Protection Advisory Council (BCPPAC) and other Canadian stakeholders;
  • Revising the PFA in Appendix 1 of directive D-00-07: Phytosanitary requirements to prevent the introduction and spread of apple maggot, Rhagoletis pomonella (Walsh);
  • Official surveys in the modified PFA;
  • Notifying stakeholders of the modification of the regulated area; and
  • Requiring CFIA Movement Certificates for all regulated articles moving into the PFA from outside it, as per D-00-07.

Scenario 3: Dissolve the PFA and deregulate R. pomonella

If R. pomonella is present in the PFA, but the CFIA determines that it would be impossible, impractical or cost prohibitive to apply official control measures to modify the boundaries of the PFA or to eradicate the pest, the CFIA will deregulate this pest. The pest would then be managed at the producer level, as per recommendations from the Province of British Columbia.

This means that if R. pomonella is found to be established and widespread or if Option 2 is rejected, the CFIA will take steps to deregulate this insect. The deregulation process will include the following:

  • Consulting BCPPAC, the B.C. provincial government and other Canadian stakeholders;
  • Revising this RMD to record the decision to deregulate R. pomonella;
  • Revoking directive D-00-07: Phytosanitary requirements to prevent the introduction and spread of apple maggot, Rhagoletis pomonella (Walsh);
  • Removing R. pomonella from the List of Pests Regulated by Canada;
  • Revising the import requirements for regulated articles from the United States in the Automated Import Reference System (AIRS);
  • Updating Schedule II of the Plant Protection Regulations;
  • Notifying international trading partners and stakeholders in other provinces; and
  • Negotiating revised export requirements with foreign national plant protection organizations, if necessary.

In addition, the CFIA would not initiate any further survey activities targeting R. pomonella.

Note: The CFIA recommends that the Province of British Columbia and industry stakeholders develop contingency plans for R. pomonella in preparation for possible federal deregulation of this pest in the future.

10.0 Stakeholder communications

The CFIA consulted with industry stakeholders and members of BCPPAC in the development of this document. BCPPAC includes representatives from the tree fruit and nursery industries, the B.C. provincial government, the Pest Management Regulatory Agency, Agriculture and Agri-Food Canada research scientists, universities and the CFIA.

11.0 References

D-00-07: Phytosanitary requirements to prevent the introduction and spread of apple maggot, Rhagoletis pomonella [Walsh]

ISPM 04: Requirements for the establishment of pest free areas

ISPM 8: Determination of pest status in an area

ISPM 26: Establishment of pest free areas for fruit flies [Tephritidae]

Rhagoletis pomonella (Apple Maggot) – Fact Sheet

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