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RMD-14-02: Revision of the geographic boundaries of the regulated areas for the blueberry maggot Rhagoletis mendax Curran in the province of Ontario

Date issued: July 21, 2014


As described by the International Plant Protection Convention (IPPC), Pest Risk Analysis (PRA) includes two 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.

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1.0 Summary

Rhagoletis mendax, the blueberry maggot (BBM), is a regulated pest for Canada and the movement of blueberry fruit, blueberry plants and used blueberry fruit containers is regulated by the Canadian Food Inspection Agency (CFIA) under Schedule II of the Plant Protection Act. The purpose of these regulations is to mitigate the human-assisted spread of BBM from areas in Canada where the pest is established into areas where it does not occur. Nonetheless, in the 1990s, BBM was detected in pockets in southern Ontario and southwestern Quebec.

The boundaries of the BBM regulated area in Quebec were amended in 2012 in order to recognize the change in the distribution of this pest in the province. Recent changes to the distribution of BBM in southern Ontario and a request from Ontario stakeholders have triggered a review of the regulated areas in Ontario.

This risk management document (RMD) describes CFIA's decision to amalgamate the geographic boundaries of the regulated areas for BBM in the province of Ontario to reflect that BBM is established in southern areas of the province. This decision does not change the regulatory status of this pest in Canada, or the phytosanitary requirements for the importation of regulated articles. Nor does it change the requirements for the movement of regulated articles from BBM regulated areas to non-regulated areas of Canada. British Columbia and Newfoundland and Labrador remain pest free areas, based on CFIA surveys, and the Prairie Provinces and Territories are also considered non-regulated areas. These regions are not impacted by this decision.

2.0 Purpose

The purpose of this RMD is to record the decision to change the geographic boundaries of the regulated areas for BBM in Ontario, following consultation with Canadian stakeholders.

3.0 Scope

This RMD provides scientific information on the biology and distribution of BBM in Canada and describes the current status of BBM in Ontario. It also describes the phytosanitary measures that are in place in Canada to mitigate the human-assisted spread of this pest to new areas. This RMD records the decision to change the geographic boundaries of the regulated areas for BBM in the province of Ontario to reflect that BBM is established in some areas of the province.

4.0 Definitions, abbreviations and acronyms

Definitions for terms used in this document can be found in the Plant Health Glossary of Terms.

5.0 Background

Rhagoletis mendax Curran, blueberry maggot (BBM), was first reported in the Maritimes in the 1930s. Although this insect is native to northeastern North America it does not occur throughout the continent and it is considered to have a limited distribution within Canada. Prior to 1993, when this pest was detected for the first time in southern Ontario, BBM was believed to be restricted to Nova Scotia, Prince Edward Island and New Brunswick. In 1996, BBM was also detected in southwestern Quebec. This pest has still not been reported from the Prairie Provinces or Territories, and annual CFIA surveys confirm that BBM is not present in Newfoundland and Labrador, nor in British Columbia.

BBM is a regulated pest for Canada and the movement of blueberry fruit, blueberry plants and used blueberry fruit containers is regulated by the CFIA under Schedule II of the Plant Protection Act. The purpose of these regulations is to mitigate the human-assisted spread of BBM from areas in Canada where the pest is established into areas where it does not occur.

CFIA considers those regions where BBM has been detected to be "regulated areas" and regions where BBM has not been detected to be "non-regulated" areas (Figure 1). Facilities and farms that are located in any regulated area in Canada or in the United States must meet the requirements of CFIA directive D-02-04 in order to move blueberry fruit, or other regulated articles, to non-regulated areas of Canada. D-02-04 also includes an option for blueberry farms to participate in the Blueberry Certification Program (BCP). Many commercial blueberry operations elect to participate in the BCP in order to facilitate the movement of blueberry fruit from regulated to non-regulated areas.

Figure 1: Shows the areas regulated for BBM in Canada in April 2014, including: Nova Scotia; New Brunswick; Prince Edward Island; Quebec along the south and north shores of the St. Lawrence River; and individual positive grower and township sites in Ontario (see Figure 2 for an enlarged, detailed image for Ontario).

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Shows the areas regulated for blueberry maggot in Canada in April 2014.

6.0 Blueberry production and blueberry maggot status in Ontario

More than 200 ha (500 acres) of highbush blueberries are grown in southern Ontario, in hardiness zones 5 to 7. Lowbush blueberries are cultivated on a smaller scale in Ontario. Most lowbush blueberries are harvested from wild stands (managed or not). These wild blueberries grow naturally in northern or eastern Ontario, where soils are more acidic than the limestone-based soils in southern Ontario. Most blueberries in Ontario are harvested as pick-your-own, or hand harvested for local markets. A small percentage of the crop is machine-harvested.

The CFIA uses yellow sticky traps baited with ammonium acetate for its annual BBM surveys across Canada. The data from trapping in Ontario clearly demonstrates that BBM is present at several locations in southern Ontario and has continued to spread since it was first discovered in 1993. By 2009, the CFIA had detected BBM at eight commercial highbush farms in townships across southern Ontario along the north shore of Lake Erie and a persistent native population in a large wild planting of highbush blueberries in the Wainfleet Bog, Niagara. By 2012, the CFIA had detected BBM at five additional sites and by 2013 at another eight sites. The map in Figure 2 shows regulated areas in Ontario. These regulated areas include individual grower sites where BBM has been detected and entire townships in cases where host material is growing within 500 m of a positive grower site. There are likely many more infested sites in southern Ontario that have not yet been discovered.

Figure 2: Regulated areas in Ontario, as of 2013. The black dots show regulated grower sites and the red areas are regulated townships.

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Regulated areas of blueberry maggots in Ontario, as of 2013. Description follows.

Description for Figure 2

Regulated municipalities: Charlotteville (Haldimand-Norfolk Regional Municipality); Wainfleet, Pelham (Niagara Regional Municipality).

Regulated grower sites (from west to east): Two sites, Essex County; seven sites, Elgin County; one site, Oxford County; one site, Brant County; one site, Hamilton Division; one site, Haldimand-Norfolk Regional Municipality; one site, Hastings County.

7.0 Pest risk assessment information

Common names

English common names of Rhagoletis mendax Curran include: blueberry maggot, blueberry maggot fly, and historically apple maggot of blueberries (prior to 1932).


R. mendax is native to eastern North America.


The primary host of BBM is blueberry, both highbush (Vaccinium corymbosum) and lowbush (V. angustifolium, V. myrtilloides and V. vacillans). Other suitable hosts include hillside blueberry (V. pallidum), deerberry (V. stamineum) and huckleberry (Gaylussacia spp.).

Current distribution

BBM is present in Canada in New Brunswick, Nova Scotia, Prince Edward Island and in southern Ontario and Quebec. Pest free areas in Canada, based on annual surveys, include the provinces of Newfoundland and Labrador, and British Columbia. BBM is also present in several states in the United States: Alabama, Connecticut, Delaware, Florida, Georgia, Illinois, Indiana, Kentucky, Maine, Maryland, Massachusetts, Michigan, Missouri, New Hampshire, New Jersey, New York, North Carolina, Ohio, Pennsylvania, Rhode Island, South Carolina, Tennessee, Vermont, Virginia and West Virginia.

Likelihood of introduction to new areas

BBM may be introduced to new areas via host fruit, host plants with roots, soil, and used containers that are moved from infested areas. The CFIA considers the risk of human-assisted spread of BBM into new areas to be high.

Natural spread potential

Natural dispersal is considered a low risk. It is limited because the adults are weak flyers and tend to stay mostly in the vicinity of the host plants and near the ground. Also, BBM adults tend to form stable populations in the same locale in successive years and seldom take flight for more than a few inches from leaf to leaf or from one plant to another. Dispersive flights have been observed in other Rhagoletis species deprived of suitable fruits for oviposition. Such flights have been inferred for BBM from higher fly captures in lowbush blueberry crop fields adjacent to vegetative fields that were recently pruned, but the distances involved were less than 300 metres. On present evidence, no Rhagoletis species has been reported to make dispersal flights that would be more than local in scope.

Establishment potential

The establishment potential for BBM is considered to be high because this insect is sufficiently cold-tolerant that it could survive in most areas where there is wild and cultivated blueberry production in Canada.

Nonetheless, BBM is unlikely to be capable of surviving and establishing in northern areas of Quebec and Ontario, even in areas where hosts are present, due to the cold climate. Cold soil temperature has been reported to have a significant impact on overwintering BBM pupae and soil temperatures below -23°C are considered a key factor limiting the spread of BBM.

Current modelling work and field reports suggest that unreliable temperature patterns, particularly any late spring or early fall frosts that destroy the berry crop, are likely to be the most important factor limiting northward expansion of BBM. This means that although BBM may survive for a short period of time in northern areas, long-term establishment is unlikely.

Figure 3 shows the potential range of BBM within southern Ontario, southwestern Quebec and the Maritime Provinces. This projection was created using historical climate data (1950-2000). BBM is able to establish from plant hardiness zones 3b to 8b.

Figure 3: Projected climate suitability for BBM. Areas marked dark green on the map are considered unsuitable for BBM. Yellow areas are likely to be suitable for long-term establishment of this insect. Light green areas may be suitable for BBM in some years.

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Projected climate suitability for blueberry maggot. Description follows.

Description for Figure 3

This map depicts the climate range of the blueberry maggot within southern Ontario, southwestern Quebec and the northeastern United States. Suitable climate occurs from plant hardiness zones 3b to 8b. This map also depicts a cluster of blueberry production facilities in La Route Bleue in southern Quebec and the Lac Saint-Jean region. Black dots mark the areas in which blueberry maggot is known to occur. In the United States, there are a few dots per state from Ohio south to Virginia and east to Maine. The density of the dots increases significantly in southeastern Maine. In Canada there is a concentration of dots stretching from the London region east to Hamilton and then in Monteregie and in the Atlantic Provinces.

Potential economic impact

BBM is a serious pest in eastern North America. The direct impacts of BBM on fresh fruit include yield and quality reduction as a result of larval feeding within the fruit. Producers also experience increased costs related to pest control. Indirect effects include those costs associated with exporting fresh blueberries to countries that require products to be certified free from BBM. The overall economic impact associated with BBM is rated medium to account for reductions in berry production and quality of fresh product, and for additional costs that may be incurred for monitoring, control, post-harvest handling and export certification.

Although the marketability of fresh fruit may be reduced, the marketability of fruit for processing is not affected by BBM and the impact of this pest in areas that produce fruit exclusively for processing is considered negligible. For instance, in the Maritime Provinces, crop loss due to BBM is considered minimal in lowbush-producing areas.

Establishment of BBM in a new region could threaten growers with pest-control costs in addition to costs already incurred to control other insect pests on blueberry plants. However, many insecticides that are used to control these other pests are also effective against BBM.

The presence of Drosophila suzukii (spotted wing drosophila, SWD) in southern Ontario since 2010 is an important consideration. SWD has had a significant impact on pest management practices in blueberries and regular insecticide applications (3-4 treatments per season) are now required in order to harvest a marketable crop. Many of the pesticides used to control SWD would also be effective in controlling BBM. This means that the relative costs that would be associated with the presence of BBM are diminished and, in fact, BBM is less of an economic concern to blueberry production than SWD.

Natural enemies of BBM may be present in blueberry fields and may contribute to pest control. However, these are unlikely to reduce BBM populations below damaging levels on their own. Other integrated pest management practices can be used in the production site to control BBM. In New Brunswick, for instance, blueberry growers apply insecticides to control BBM, but only on about 15% of the blueberry land in any crop year.

Potential trade impacts

BBM is present in various states in the United States and in various provinces in Canada. British Columbia, Newfoundland and Labrador are considered to be free of BBM. Regulated commodities must meet specific conditions in order to be moved from regulated areas of Canada and the United States to non-regulated areas of Canada. Depending on the case, a Movement Certificate, a Phytosanitary Certificate or Movement Certification Label is required in order to certify the shipment of regulated commodities as free from BBM. The United States does not have any federal regulations in place for BBM. This means that blueberry fruit entering the United States from Canada does not require inspection by CFIA, certification under the Blueberry Certification Program, or issuance of phytosanitary certificates.

Existing domestic, provincial and other programs

The Blueberry Certification Program (BCP) is a program designed to establish pest free places of production and to allow the movement of regulated commodities from regulated areas in Canada and the United States to non-regulated areas in Canada. This program is based on approval of growers, pest monitoring and control procedures, grading, fruit sampling and testing. All blueberries shipped under the BCP must originate from growers approved by the National Plant Protection Organization (NPPO) of the country of origin or approved under its authority and must originate from a monitored production area. Shipments must be free of all living stages of quarantine pests and meet the conditions for other regulated pests, and be practically free of soil, sand, leaves and plant debris, including woody materials.

British Columbia and Newfoundland and Labrador both regulate the movement of commodities that could be infested by BBM. British Columbia's restrictions are described in the province's Blueberry Maggot Control Regulations (B.C. Regulation 280/90). Newfoundland and Labrador's are described in the Newfoundland Berry Regulations (Newfoundland Regulation 1195/96).

8.0 Pest risk management decision to amalgamate the BBM regulated areas in southern Ontario

The CFIA has determined that the area south of the northern municipal boundary of Horton and Renfrew; Roads 132, 41, 28, 121, 118 and 11; and of the northern boundary of Simcoe County (refer to Figure 4) in Ontario should be regulated for BBM. This area includes the majority of commercial highbush and lowbush blueberry production.

Figure 4: The amalgamated regulated area for BBM in Ontario. All of southern Ontario is included. The northern boundary of the regulated area is defined by: the northern municipal boundary of Horton and Renfrew; Roads 132, 41, 28, 121, 118 and 11; and the northern boundary of Simcoe County.

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The amalgamated regulated area for blueberry maggot in Ontario. Description follows.

Description for Figure 4

Regulated counties (from south-west to north-east): Essex County, Chatham-Kent Division; Lambton County; Elgin County; Middlesex County; Oxford County; Norfolk County; Brant County; Haldimand County; Hamilton Division; Niagara Regional Municipality; Huron County; Perth County; Waterloo Regional Municipality; Wellington County; Halton Regional Municipality; Bruce County; Grey County; Dufferin County; Peel Regional Municipality; Simcoe County; York Regional Municipality; Toronto Division; Durham Regional Municipality; Kawartha Lakes Division; portion of Muskoka District Municipality east of Road 11 and south of Road 118; portion of Haliburton County south of Road 118; Peterborough County; Northumberland County; portion of Hastings County south of Road 28; Prince Edward Division; portion of Renfrew County south of Roads 28, 41 and 132 and within the boundaries of Horton and Renfrew; most of Lennox and Addington County, south of Road 28; Frontenac County; Lanark County; Leeds and Grenville United Counties; Ottawa Division; Stormont, Dundas and Glengarry United Counties; Prescott and Russell United Counties.


9.0 Stakeholder communications

In January 2014, the CFIA received a request from the Ontario highbush blueberry stakeholders to revise the geographic boundaries of the regulated areas for BBM in Ontario. Specifically, the CFIA was asked to modify CFIA policy D-02-04 so that BBM is considered to be established in the southern portion of Ontario.

The CFIA consulted with Canadian stakeholders in June 2014 and received strong support for amalgamating the regulated areas as described above.

10.0 Next steps

The results of this consultation will be used to change how the CFIA regulates BBM in Ontario. As of 2014, only those facilities located within the new regulated area that intend to ship blueberry fruit to non-regulated areas of Canada will be required to participate in the BCP. Notices will be sent to blueberry producers, distributors and other industry stakeholders to inform them of the change and to increase awareness with respect to the domestic movement requirements designed to mitigate further human-assisted spread of BBM to non-regulated areas. The CFIA will revise directive D-02-04 to describe the new geographical boundaries of the BBM regulated area in Ontario.

11.0 References


Canadian Food Inspection Agency (CFIA): Plant Health Glossary of Terms

Ministère des Affaires Municipales, Régions et Occupation du Territoire - (french only)

Ontario Ministry of Agriculture, Food and Rural Affairs

Plant Protection Act

Plant Protection Regulations


D-02-04: Phytosanitary requirements for the importation from the continental United States and for domestic movement of commodities regulated for blueberry maggot. CFIA, Ottawa.

RMD-11-03: Revision of the geographic boundaries of the regulated areas for the blueberry maggot Rhagoletis mendax Curran in the provinces of Ontario and Quebec. 2012. CFIA, Ottawa.

Damus, M. 2009. Request for biological information, estimate of potential distribution of R. mendax Curran in Lac St-Jean area of Quebec. CFIA. PRA No. 2002-37. Map updated 2014.

Garland, J.A. and Dobesberger, E.J. 2002. Plant Health Risk Assessment on blueberry maggot. CFIA. PRA 2002-37.

Garland, J.A. and Watler, D.E. 1997. Pest Risk Assessment on blueberry maggot with particular reference to Lac St-Jean, Quebec. CFIA. PRA 1997-63.

Watler, D.E. 1989. Pest Risk Analysis on blueberry maggot. CFIA. PRA 1989-12.

12.0 Endorsement

Approved by: Chief Plant Health Officer

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Chief Plant Health Officer

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