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RMD-12-02: Halyomorpha halys Stål (Brown Marmorated Stink Bug)

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Issued: 2012-03-20


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.

Table of Contents

1.0 Executive Summary

Halyomorpha halys Stål was first detected in Pennsylvania in 1996, and as of the spring of 2011, had spread to 32 states, and had been intercepted multiple times in Canada. This insect hitchhikes on conveyances and other pathways, and due to its close proximity to the Canada/U.S. border and its biology as a strong flyer, direct flight across the border is also of concern. Therefore, there does not appear to be any practical measures which could prevent spread into and within Canada. After review of the science based information available, the Canadian Food Inspection Agency (CFIA) has decided not to add H. halys to the List of Pests Regulated by Canada.

2.0 Purpose

This pest risk management document (RMD) describes the regulatory rationale and regulatory decision for H. halys, the Brown Marmorated Stink Bug (BMSB).

3.0 Scope

This RMD is the formal record of the pest risk management decision that was taken following completion of the CFIA’s pest risk assessment in 2011 and observations with respect to the presence of H. halys in Canada, North America and the rest of the world.

Information pertaining to current import requirements for specific plants or plant products may be obtained from the CFIA Automated Import Reference System (AIRS)

4.0 Definitions, abbreviations and acronyms:

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

5.0 Background:

The first Pest Risk Assessment for the H. halys was completed in December 2003, and subsequent Pest Risk Assessment completed in 2011 confirms the initial recommendation to not regulate this pest in Canada. H. halys is native to South Korea, Japan, Taiwan, and eastern China, and was initially detected in North America in Pennsylvania in 1996. As the time of the 2003 PRA, this H. halys had spread to New Jersey and had been detected in Maryland and South Carolina. These detections and rapid spread raised concern about the possibility and consequences of introduction of H. halys into Canada.

In Canada since 2000, H. halys has been intercepted on manufactured goods imported from China, in association with shipping containers, on poplar lumber imported from Virginia, in imported boxes of spa towels, and most recently, was reported by a homeowner in Ontario. In the eight years since the 2003 Pest Risk Assessment, H. halys is now reported in 32 states, has become better established in Pennsylvania and New Jersey (where it was first detected) and its biology and ecology in North America is now better understood.

6.0 Pest Risk Assessment Summary

In September 2010 CFIA, initiated an update to the 2003 Pest Risk Assessment, with the most recent Pest Risk Assessment completed in April 2011. The PRA was requested in order to update the distribution of the pest in the U.S.; to re-evaluate the likelihood of entry into Canada; to determine whether eradication would be possible if H. halys is able to establish in an area in Canada; to incorporate new information from reports of crop damage in the U.S. and update any new information since the 2003 assessment was completed; as well as to evaluate the potential economic impact of H. halys introduction to the grape and wine industry.

6.1 Pest Biology

Life History

H. halys overwinters in protected places, including houses. It aggregates in large numbers in structures to overwinter, and it remains inactive in these structures until the end of May. In the spring, adults leave the overwintering site, seek potential host plants, mate, and lay eggs. H. halys lay multiple egg masses throughout their life span. In the U.S., H. halys has been observed laying eggs from May to late August.

Only one generation per year has been recorded in Pennsylvania, the state where the pest was first established in North America, and this occurrence of one generation per season is predicted to be the same in much of Canada. One to six generations have been reported in H. halys’ native Asian range.

Host Range

In Asia, H. halys has been documented on over 60 host plants, from 23 genera, including Brassicaceous, Cucurbitaceous, Fabaceous, Rosaceous, and Solanaceous plants, many of which also occur in Canada. Primary hosts are woody plants, including fruit trees and ornamentals. In springtime, this insect infests cedar and other trees, including apple and peach. In summer, it shifts to annual crop plants, such as rape, pea, cucumber, kidney bean, and soybean. Secondary hosts include ornamental plants.

Means of Dispersal and Spread

H. halys is a free-living organism and does not require a specific host or commodity to aid its spread. This insect moves easily between hosts, migrating from plants with early-ripening fruit to those with late ripening fruit. Like other stink bugs, H. halys are capable of local dispersal to feed on susceptible hosts, and are capable of long distance flight. They are also capable of hitchhiking for long distances on conveyances such as shipping containers, recreational vehicles, cars, etc. The transport of hitchhiking H. halys in vehicles and cargo is thought to have contributed to the wide distribution of H. halys in the U.S. since 2003.

6.2 Distribution

H. halys is native to South Korea, Japan, Taiwan, and eastern China. It was first found to be established in the U.S. in 1996 in Allentown, Pennsylvania. Since its initial establishment, it had spread to 37 counties in Pennsylvania as of September 2010. Established populations have also been reported throughout the state of New Jersey. From its original area of infestation in Pennsylvania this pest has now been detected in 32 states in the U.S., from Pennsylvania to as far west as California and Oregon, as far south as Mississippi. In Europe, H. halys has been detected in Switzerland.

6.3 Pathways

H. halys could be introduced to Canada through the importation of fresh fruits, wooden containers, crating, storage boxes, and lumber. Aircraft have also been identified as potential pathways based on interceptions in the U.S. and Canada. Hitchhiking on various types of vehicles and bulk cargo containers is also a major concern. This insect has demonstrated ability to survive long-distance transportation.

Entry Potential

This insect has been intercepted in Canada several times since 2008. H. halys exhibit shelter seeking behaviour which contributes to the widespread distribution of this pest through hitchhiking. This behaviour results in H. halys being moved from one place to another through various means of transportation including cars, trucks, campers, mobile homes, and railroads. Also important to the entry potential of H. halys is its proximity to the Canadian border. H. halys is found throughout Pennsylvania and New Jersey, and with north-west Pennsylvania being approximately 200 km from southern Ontario, the likelihood that H. halys will naturally spread to Canada is expected. Previous interceptions and the numerous pathways for introduction mean that the potential for H. halys to enter Canada is considered high.

Establishment Potential

If introduced, H. halys may be able to establish in some parts of Canada, especially in urban and suburban landscapes, taking advantage of opportunities provided by human dwellings and other heated structures to survive the winter. It may then invade orchards, vineyards, and agricultural areas. Its ability to feed off a wide array of hosts means that it would be able to find suitable hosts from coast to coast.

The likelihood of establishment of H. halys in Canada is considered high. However, there is a great degree of variability within Canada, where there is lower potential for establishment in colder areas of the country, and a much higher likelihood of establishment in more southern parts of the country along the U.S. border where the majority of Canadians live and where most greenhouses, orchards and farms in Canada are found.

Spread Potential

The spread potential of H. halys in Canada is impacted by both natural and human assisted factors. In terms of natural spread potential, H. halys has the ability to find suitable hosts across Canada, and as a strong flyer also has the ability to move easily between hosts. In terms of human-assisted spread potential H. halys is a prolific hitch hiker and as such is spread easily by humans when travelling or shipping goods. Due to these factors, the spread potential of H. halys, should it become established in Canada, is considered likely.

6.4 Potential Economic and Environmental Consequences

  • Predicted to have only one generation a year in Canada, H. halys may still become a significant economic pest in fruit orchards and vineyards. Due to its tendency to feed on multiple hosts H. halys is a pest of several important crops in its native range. It has been reported on shade and fruit trees, ornamentals, vegetables, and leguminous crops. Damage to fruits can result in loss of market access. The premature abortion and damage caused to fruit due to feeding makes the fruit unmarketable for fresh fruit sale and the resultant loss of market access for the fruit once damaged is of great concern to growers.
  • There is concern that H. halys infestations in vineyards and the resultant contamination of wine grapes may cause wine taint and may lower the quality of wine produced. However, there have been limited scientific studies done to describe and quantify this phenomenon with particular reference to H. halys. Tainting of wine by insect contaminants has already being described for the multi-coloured Asian lady beetle, Harmonia axyridis. However, the level of infestation that will cause wine taint is not well known, and would need further study.
  • H. halys is considered to be a nuisance pest as well as being an agricultural pest (pest of plants) because of its ability to invade structures, including homes, outbuildings and public and commercial buildings and because H. halys discharges a foul-smelling scent when disturbed.
  • In addition to physical damage caused by feeding of nymphs and adults, H. halys has been reported to be a vector of a phytoplasma disease (witches’ broom) of the Princess tree, Paulownia tomentosa (Thunb.) in Japan. Although the status of H. halys as a vector of other phytoplasmas is not well known, there exists the possibility it could transmit other phytoplasmas that, due to its tendency to feed on multiple hosts, could infect a broad range of plants.
  • Economic and environmental consequences of H. halys introduction into Canada are considered to be moderate from a phytosanitary point of view; however, taking into consideration its classification as a nuisance pest, the economic and environmental consequences are thought to be high.

7.0 Risk Management Considerations

The following section provides a synopsis of factors considered important to the risk management decision.

Distributional Factors Considered

Since the 2003 Pest Risk Assessment was completed the distribution of H. halys has changed significantly. From four infested states in 2003, this insect has now been detected in 32 states from coast to coast, from as far north as Pennsylvania, to as far south as Mississippi.

Entry, Establishment, and Spread Potential Factors Considered

  • The ability of H. halys to survive in transit is well demonstrated.
  • As this pest can move on almost any conveyance, available regulatory procedures would not be sufficient to prevent entry.
  • Natural spread through flight across the Canada/U.S. border is highly likely.
  • Estimates regarding the ability of H. halys to establish across Canada are heavily influenced by a number of factors:
    • The wide range of host genera available from coast to coast make establishment more likely;
    • The ability of this insect to survive the winter in protected environments increases its likelihood of establishment;
    • The ability to complete a life cycle in one year in climates similar to those found in the southern portion of Canada, combine to result in a high potential for establishment in much of Canada.

Economic and Environmental Consequence Factors Considered

  • Both the U.S. and the European Union have determined they will not regulate H. halys, so the presence of H. halys will not impact trade.
  • Considering the volume of private and commercial traffic crossing the Canada/U.S. border every day, it is not possible to inspect every conveyance, nor is it economically feasible (both in practical terms of inspection delivery, and in terms of disruptions to the flow of goods and persons across the border).
  • There are broad spectrum insecticides registered for use on stink bugs.

Gaps and Uncertainties

  • The overwintering biology of this insect is not fully understood, particularly its spread potential and other impacts if it becomes established in Canada.
  • The level of H. halys infestation that will cause wine taint, and the impacts of this in terms of wine quality are not quantified.
  • The status of H. halys as a vector of phytoplasmas due to its polyphagous nature and its biology as a sucking insect is not well understood.
  • Initial infestations of H. halys have been successfully eradicated in South Carolina, California, and Maine; however the ability to eradicate well established populations is not well documented. Given the spread of H. halys in the U.S. since 2003, sustained eradication is unlikely as reintroduction will prevent maintenance of pest free status even if localized eradication was achieved.

International Obligations

The IPPC describes a quarantine pest as: “a pest of potential economic importance to the area endangered thereby and not yet present there, or present but not widely distributed and being officially controlled”. Official control for quarantine pests is defined as “the active enforcement of mandatory phytosanitary regulations and the application of mandatory phytosanitary procedures with the objective of eradicating or containment of quarantaine pests or for the management of regulated non-quarantine pests”. Measures applied on imports should be consistent with the principles of non-discrimination (ISPM No. 5, Supplement No. 1, Guidelines on the interpretation and application of the concept of official control for regulated pests.) In other words, in order to implement import restrictions for BMSB, there must be equivalent official measures to eradicate or contain and prevent the spread of H. halys within Canada.

8.0 Risk Management Decision:

As it is not possible to prevent the spread of H. halys to Canada, nor is there a reasonable possibility of sustained eradication if H. halys becomes established in Canada, the CFIA has taken the decision not to include Halyomorpha halys Stål in the List of Pests Regulated by Canada.


  • H. halys has been reported in 32 states in the U.S. and there are no regulatory measures in place to prevent further spread.
  • H. halys is expected to be introduced to Canada via multiple pathways, including commercial traffic from infested areas of the world and via natural spread.
  • H. halys is polyphageous and is able to survive on a wide range of hosts.
  • H. halys will spread to and within Canada notwithstanding any regulatory measures that could be put in place by CFIA.

Potential consequences

  • H. halys is expected to spread to and within Canada to areas with suitable climatic conditions and where hosts are available.
  • H. halys may become a nuisance pest and agricultural pest in Canada

Next Steps

  • The RMD will be posted on the CFIA website
  • No changes in import requirements are required as a result of this decision.
  • No changes to import inspection procedures are anticipated as a result of this decision
  • There are no anticipated human resources implications or financial costs

9.0 Stakeholder Communications

The following stakeholders will be notified of the risk management decision that was made in 2003 and upheld during this review.

  • CFIA Program Officers, inspection staff, etc.
  • Other government organization (e.g. PMRA, AAFC, Provincial departments of agriculture)
  • Industry stakeholders

10.0 References:

Ameen, A. 2011. Plant Health Risk Assessment, Brown Marmorated Stink Bug, Halyomorpha halys Stal. Plant Health Risk Assessment Unit, Canadian Food Inspection Agency.

CABI. 2011. Crop Protection Compendium. CAB International, Wallingford, U. K.

Garland, J. 2003. Plant Health Risk Assessment, Brown Marmorated Stink Bug, Halyomorpha halys (Stal). Plant Health Risk Assessment Unit, Canadian Food Inspection Agency.

Hamilton, G. C, P. W. Shearer & A. L. Nielsen. 2008. Brown Marmorated Stink Bug - A non-native insect in New Jersey. Fact Sheet #: FS002 (anglais seulement). Cooperative Extension, New Jersey Agricultural Experiment Station, Rutgers, The State University of New Jersey. 2 pp. Source, http://njaes.rutgers.edu/pubs/publication.asp?pid=fs002 Accessed, March 14, 2011.

Hamilton, G. C. 2009. Brown Marmorated Stink Bug. American Entomologist, 55(1): 19-20.

Hoebeke, E. R. & M. E. Carter. 2003. Halyomorpha halys (Stål) (Heteroptera: Pentatomidae): a polyphagous plant pest from Asia newly detected in North America. Proceeding of the Entomological Society of Washington, 105: 225-237.

IPPC, 2006. International Standards for Phytosanitary Measures, ISPM 01 Phytosanitary principles for the protection of plants and the application of phytosanitary measures in international trade, Secretariat of the International Plant Protection Convention, Food and Agriculture Organization of the United Nation, Rome, Italy.

IPPC, 2007. International Standards for Phytosanitary Measures, ISPM 02 Framework for pest risk analysis, Secretariat of the International Plant Protection Convention, Food and Agriculture Organization of the United Nation, Rome, Italy.

IPPC (updated annually). International Standards for Phytosanitary Measures, ISPM 05 Glossary of phytosanitary terms, Secretariat of the International Plant Protection Convention, Food and Agriculture Organization of the United Nation, Rome, Italy.

IPPC, 2004. International Standards for Phytosanitary Measures, ISPM 11 Pest risk analysis for quarantine pests including analysis of environmental risks and living modified organisms, Secretariat of the International Plant Protection Convention, Food and Agriculture Organization of the United Nation, Rome, Italy.

Jacobs, S. 2010. Brown Marmorated Stink Bug, Halyomorpha halys (anglias seulment). Department of Entomology, Pennsylvania State University. Revised November 2010. Source, http://ento.psu.edu/extension/factsheets/brown-marmorated-stink-bug Accessed, March 14, 2011.

Leskey. T. 2010. Brown Marmorated Stink Bug: Damage Survey and Monitoring Efforts. Appelachian Fruit Research Station, USDA-ARS, Kearneysville, WV.

Nielsen, A. L. & G. C. Hamilton. 2009. Seasonal occurrence and impact of Halyomorpha halys (Hemiptera: Pentatomidae) in tree fruit. Journal of Economic Entomology, 102(3): 1133-1140.

Wermelinger, B., D. Wyniger & B. Forster. 2008. First records of an invasive bug in Europe: Halyomorpha halys Stål (Heteroptera: Pentatomidae), a new pest on woody ornamentals and fruit trees? Bulletin de la Société Entomologique Suisse, 81: 1-8.

11.0 Endorsement

Approved by:

Chief Plant Health Officer