Pest Risk Management Decision Document – Brown Spruce Longhorn Beetle (Tetropium fuscum)
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 https://www.ippc.int/.
1.0 Executive Summary
As Brown Spruce Longhorn Beetle (BSLB) continues to spread within central Nova Scotia, with a low to moderate provincial risk-rating (albeit with uncertainty), a re-evaluation of its risk to Canada was carried out, resulting in proposals for subsequent adjustment of management activities by federal, provincial, and industry partners. Nova Scotia, New Brunswick, and certain industry partners have proposed that national deregulation of BSLB is the logical next step, however scientific information, and the immediate need to protect the rest of Canada from the economic impacts of BSLB spread suggest that, in the short- to medium-term, continued regulation of BSLB is required. This RMD serves as a vehicle to consult with a broad range of stakeholders as to the appropriate risk-based management approach for BSLB.
To consult on a planned risk management decision for the management of Brown Spruce Longhorn Beetle, Tetropium fuscum (Fabricius).
This Risk Management Document (RMD) summarizes the CFIA's decision for management of Brown Spruce Longhorn Beetle, including aspects of pest-status, regulated areas, potential provincial and industry best management practices, and outreach and communications materials.
Information pertaining to current import requirements for specific plants or plant products may be obtained from the CFIA Automated Import Reference System.
4.0 Definitions, abbreviations and acronyms
Definitions for terms used in this document can be found in the Plant Health Glossary of Terms at or the IPPC Glossary of Phytosanitary Terms at www.ippc.int.
Brown Spruce Longhorn Beetle (BSLB) is a regulated pest in North America as it is known to be a pest of spruce trees. It was first identified by Canadian Forest Service (CFS) scientists in 1999 in Point Pleasant Park, adjacent to the port in Halifax, Nova Scotia. Native to northern and central Europe, its presence in an area can pose a threat to domestic and international trade of Canadian spruce products. It is thought to have arrived in Canada with wood packing material unloaded at the Port of Halifax. CFS also determined that specimens preserved from a 1990 survey of Point Pleasant Park were also T. fuscum, (originally mis-identified as T. cinnamopterum) indicating it was present since at least 1990.
Since being detected, BSLB has become established in central Nova Scotia, with several new detections found each year outside of the Containment Area established in 2007 (Appendix 1). In 2011 a single BSLB adult was captured in a trap in a national park in north-eastern New Brunswick, and another beetled was detected in 2014 in Memracook County, which represented the first finds of BSLB outside of Nova Scotia; however continued surveys indicate it is not established in New Brunswick.
From 2000 until the spring of 2006, eradication was pursued, involving the cutting and disposal of selected infested and high risk trees, and regulating high risk material movement through the issuance of Prohibitions of Movement and the Brown Spruce Longhorn Beetle Infested Places Ministerial Order which defines the boundaries of the Infested Place. Point Pleasant Park was originally placed under a Notice of Prohibition of Movement, and intensive infested tree removal and disposal efforts were undertaken within the park and the surrounding Halifax metropolitan area from 2000 until 2006. Efforts were hampered in the fall of 2003 when Hurricane Juan cut a large swath across the centre of the Province, disrupting official control efforts. Subsequent studies carried out by CFS confirmed that spruce trees weakened and blown down by the hurricane provided breeding grounds for BSLB which led to rapid population build-up and spread, further hampering control efforts.
5.1 Pathways of spread
BSLB dispersal and spread occurs naturally via beetle flight, and also via human-assisted movement of spruce forest products. The movement of high risk spruce products from areas recognized as infested with the beetle is therefore restricted under Ministerial Order. Similar movement controls have been implemented at all satellite positive sites outside the Infested Place where BSLB has been detected. In 2006, based on the broad distribution of BSLB within the Infested Place and a number of positive BSLB finds outside the Infested Place, the CFIA switched approach from eradication to containment with regulatory control aimed at slowing its spread. With additional infested sites found throughout the 2006 survey season, the "Brown Spruce Longhorn Beetle Infested Places Order - Second Revision" was implemented in the spring of 2007 to define an expanded Infested Place. Since 2007, with the aid of a more effective trap baited with a pheromone lure, surveillance for BSLB has resulted in additional detections, bringing the total number of sites with at least a single BSLB find outside the Infested Place to 106 (Appendix 1). The Infested Place now extends beyond the Halifax metropolitan area.
5.2 Drivers for change
The current approach, with individual controls on these 106 sites, does not appear to be fully effective at slowing the spread of this pest, nor is it an effective use of management efforts. The US regulates the entire province of Nova Scotia for the export of spruce logs and firewood, as the basis for appropriate containment of the pest. Further detections of BSLB outside Nova Scotia could result in the US expanding its regulations to include the neighbouring provinces. Maritime industry stakeholders have indicated that they ship a relatively low volume of unprocessed spruce exports to the US from Nova Scotia, however, the forestry industry of other provinces may be negatively affected should they be regulated by the United States in the future.
The current regulatory approach places movement restrictions on spruce products and forest product facilities within Nova Scotia. Movement restrictions imposed on spruce articles moving from the 106 infested sites not bound within the Infested Place causes logistical sourcing and processing problems for the industry. In 2013, a re-analysis of various spruce article risk pathways resulted in the removal of spruce bark and wood chips from the list of regulated articles; subsequently only spruce logs (round-wood) and firewood remain regulated.
5.3 CFIA contributions
Invasive species have increasingly become recognized as a significant concern as worldwide trade and travel have significantly increased opportunities for their introduction and subsequent domestic spread. The list of regulated pests in Canada contains over 250 species, and federal legislative control through inspection, regulation and enforcement is the key phytosanitary measures employed to mitigate the risks they pose, in conjunction with the development, adoption and implementation of appropriate International Standards for Phytosanitary Management (ISPMs) by the International Plant Protection Convention (IPPC). However, many commodities cannot be easily inspected, and the volume of importations that can be inspected is always limited in scope and time, so effective regulation relies increasingly on systems approaches and on the support of all stakeholders. Therefore, communication and public outreach are key components of the CFIA's mitigation efforts to raise awareness and garner involvement and support in managing the threat from invasive pests. The CFIA invests significant effort in outreach, and CFIA employees are regularly involved in a variety of public events to increase awareness of quarantine pests that are considered invasive.
Some of the risk-mitigation and management activities that the CFIA delivers include:
- Conducting pest risk assessments prior to the importation of new commodities
- Restriction of the introduction and spread of quarantine pests through import policies, border controls and point-of-destination product inspections
- Surveillance, to monitor pest presence and distribution
- Enforcement of regulations and associated policies
- Enhancing public awareness of risk and regulations
The CFIA has implemented numerous import control policies in order to restrict the entry and establishment of invasive plant pests. Since 1998, through its regulatory efforts on dunnage and other wood products, the CFIA has targeted high-risk import pathways through policies such as D-98-08 (Entry requirements for wood packaging materials produced in all areas other than the continental United States), stipulating requirements such as dunnage reclamation at marine ports, and a requirement for all off-continent wood products to be heat-treated or fumigated. This is in keeping with Canada's obligations as a member of IPPC. The CFIA import policy D-02-12 (Import requirements of non-manufactured wood and other non-propagative wood products, except solid wood packaging material, from all areas other than the continental United States) stipulates phytosanitary import requirements for non-manufactured wood products such as logs, wood chips, and decorative wood items from all countries except the Continental U.S.
Because of the high level of risk associated with the movement of firewood, the CFIA has carried out an extensive Don't Move Firewood campaign. Since 2008, thousands of brochures, posters and other communications products have been distributed annually through collaboration with partners. In addition, road signage highlighting the risks of moving firewood has been installed in several provinces. The CFIA also participates in public shows and exhibits in order to educate the general public about the risks of moving firewood. The CFIA has prioritized continued work on the firewood pathway (harmonising with the U.S.), drafting a proposal to revise Canada's firewood import policy in order to require heat-treatment of firewood, as well as exploring options to strengthen domestic movement risk-mitigation measures.
In 2004, the CFIA implemented ISPM 15, Regulation of wood packaging material in international trade¸ which has required all wood packaging imported to Canada from outside of continental North America to be treated to kill any wood-related pests that may be present. Given the volume of wood packaging moving in international trade, this is understood to have had a significant impact on the entry of quarantine pests of trees and forests.
5.4 Stakeholder engagement
The CFIA continues to engage with stakeholders at the national and regional levels, including outreach and surveillance efforts with federal, provincial, and industry partners. At the beginning of the BSLB eradication effort in 2000, a BSLB Task Force, comprised of representatives from the three levels of government, university and industry was formed to provide advice to the CFIA. Since 2008, the CFIA and Natural Resources Canada-CFS have co-chaired a BSLB steering committee, with participation including members from federal and provincial governments, as well as industry stakeholders, with the objective of developing a collaborative management response to BSLB. Federal membership is comprised of representatives of the CFIA, the CFS, and Parks Canada; provincial representation is based on Nova Scotia and New Brunswick; and industry representation is comprised of members from the Maritime Lumber Bureau, the Forest Products Association of Nova Scotia, the Federation of Nova Scotia Woodland Owners, and the New Brunswick Forest Products Association. The CFIA has also maintained contact with other potentially affected provinces in order to keep them informed of upcoming changes to the management of BSLB and other forest pests. The CFIA is engaged in consultations with federal and provincial partners on a National Forest Pest Strategy, a comprehensive intergovernmental body that reports to the Canadian Council of Forest Ministers. This engagement provides a common venue for discussion of key forest pests such as BSLB, and outlines guiding principles for their collaborative management on an ongoing basis.
6.0 Pest risk assessment summary
Information in this section is taken mostly from the regional Pest Risk Assessment produced by the Nova Scotia Department of Natural Resources (NSDNR 2013), as well as the latest update of the official Pest Risk Assessment for Tetropium fuscum, the brown spruce longhorn beetle, completed by the Plant Health Pest Risk Assessment Unit of the CFIA in 2008.
6.1 Pest biology
In its native Eurasia, the brown spruce longhorn beetle is a wood-boring beetle (family Cerambycidae) that typically attacks dying or stressed spruce (Picea spp.) trees. The trees may be stressed as a result of wind, lightning, drought or fire damage, or insect defoliation, and freshly-harvested trees are also frequently attacked (Schwenke 1974; Hanks 1999). BSLB can also build up damaging populations in its native area, and is known to be a primary tree-killer in Europe under outbreak conditions (Juutinen 1955; Freude et al. 1965; Schwenke 1974). In Europe, however, it is mostly recognized as a secondary forest insect (Nüsslin 1905; Crawshay 1907; Saalas 1923; Schimitschek 1953; Juutinen 1955; Lottyyniemi and Uusvaara 1977), 'cleansing' the forest of diseased and weakened trees (e.g. Schimitschek 1929).
In Canada, spruce (red, white, black, and Norway) are attacked with a preference for trees that are physiologically stressed or of 'low vigour' (slow radial growth due to either age or temporary stress) but still apparently healthy. Reports of attacks on other types of conifers in Europe, such as pine (Pinus spp.), larch (Larix spp.) and fir (Abies spp.) are very rare, often outdated and possibly unreliable; more recent tests show that the beetle does not naturally reproduce onthese other conifersin Canada (Sweeney and Smith 2002).
Research in Canada also shows that BSLB prefers stressed trees as it does in its native range (Flaherty et al. 2013), that females preferentially lay eggs on them, that larval mortality is lower, and development time is shorter than on healthy trees (J. Sweeney, Canadian Forest Service, pers. comm.; Flaherty et al. 2011; O'Leary et al. 2003). However the beetle does, when forced, lay eggs in healthy spruce trees which can survive to adulthood (Flaherty et al. 2011), and also lay eggs on less-susceptible hosts (that is, unstressed trees) when they do land on them (Flaherty et al. 2013). Although BSLB generally kills stressed trees in Canada; these same trees may recover after temporary stressors are lifted (drought, defoliation, etc.) and could potentially survive in the absence of the BSLB (O'Leary et al. 2003). Therefore, the tree-mortality this beetle can cause is not simply an alternative to that caused by other sources, but may be, at least partly, an additional source of mortality.
Trunk silhouettes and host volatiles are important in the location and identification of potential hosts on which adults land and mate. The life cycle of the BSLB generally spans one year in central Europe (Schwenke 1974), but two years may be required in colder climates (Cherepanov 1990) or when the nutritional value of the host is poor (Schimitschek 1929; Juutinen 1955), or when the tree is vigorous and healthy (Flaherty et al. 2011). Because generations may overlap, all four life stages may be present on or in the host plant during the summer months in Canada.
Other than central Nova Scotia, Canada, BSLB is widely distributed in northern and central Europe; Austria, Belarus, Belgium, Bosnia-Herzegovina, Bulgaria, Croatia, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Hungary, Italy, Lithuania, Latvia, Moldova, the Netherlands, Norway, Poland, Romania, the Russian Federation (European part), Serbia and Montenegro, Slovakia, Slovenia, Sweden, Switzerland, the Ukraine, introduced into but not established in the United Kingdom (Bilý and Mehl 1989, CABI 2012, Duff 2008). It also occurs in parts of Asia: Turkey, Siberia (Russian Federation), Kazakhstan, and Japan (CABI 2012).
6.3 Pathways of spread
Except during the relatively brief adult dispersal period, which peaks (with single or multiple peaks) sometime between late May and mid-July but may extend into August before trailing off (J. Sweeney, CFS, pers. comm.), all life stages of the BSLB are confined to the bark, phloem and sapwood of host trees. During this dispersal period, adult beetles have the capability to fly an average of 2.3 kilometres, based on laboratory flight mill data. Observational evidence suggests that the beetle has moved approximately 4km/year from its presumed point of introduction (Rhainds et al. 2011). It is believed that this combines natural and artificial spread, and that the natural spread has probably been aided by the high volume of susceptible host material remaining after Hurricane Juan of 2003; the most-infested areas of Nova Scotia lie directly in the Hurricane's path across the province (see appendix 1).
Current population levels are variable but low in most areas outside the urban core of the Halifax Regional Municipality as measured by current survey methods. Pathways for human-assisted dispersal include the transport of unprocessed spruce logs or green (i.e., not kiln dried or heat treated) lumber, particularly with attached bark; crates, pallets and dunnage (scrap green spruce lumber used to support loads), as well as spruce firewood. Lower-risk artificial pathways include large wood chips containing attached bark strips (i.e., phloem), and bark. Restricting movement of raw spruce wood products to outside the adult dispersal period mitigates the risk. Manufacturing or processing raw forest products mitigates the risk of specific pathways to acceptable levels of risk to allow movement of spruce articles.
6.4 Overall risk rating
The CFIA's 2008 PRA overall risk rating for Tetropium fuscum is Medium; establishment potential is rated High, natural spread is rated Low, and environmental and economic impact are both rated Medium. The risk components in a risk assessment are combined to give an overall risk summary, which resulted in a Medium ranking. This implies that specific phytosanitary measures are recommended to slow or restrict the spread and introduction of BSLB to uninfested parts of Canada. Spread is expected to continue at a low rate, and regulatory and control actions do play a role in slowing the ongoing artificial spread of this pest.
Although BSLB was initially thought to be a destructive pest of spruce trees because of its ability to attack and kill large, apparently healthy, spruce trees, there is recent evidence it prefers stressed trees, although it does have the ability to colonise healthy spruce trees. Its risk rating in the CFIA PRA was changed from High in 2000, to Medium in 2008.
There is still lingering uncertainty around how it may behave in different environments in Canada, as well as when combined with other tree-stressors such as climate-change and pests such as Spruce budworm and Spruce bark-beetle. The Nova Scotia Department of National Resources (NSDNR) recently produced a regional PRA on BSLB with the overall conclusion that "BSLB is determined to pose a low-moderate risk to the province of Nova Scotia" (NSDNR 2013). The assessment states that the overall risk posed by BSLB to the province is considered low; however, due to uncertainties and information needs, the ranking was raised slightly to 'low-moderate'.
7.0 Pest risk management
The BSLB steering committee has discussed the next steps for the ongoing and collaborative management of BSLB, with recent recognition and agreement that BSLB poses a lower risk to spruce trees in Nova Scotia and New Brunswick than previously thought. The provinces of Nova Scotia and New Brunswick, as well as key industry stakeholders, have therefore proposed national deregulation of BSLB as a logical path to pursue for Canada. This would require consultation with a broad range of stakeholders in Canada, including all provinces and key industry associations, not least due to the potential for increased regulation by the US, although should the US indicate concern with this approach, heat-treatment and compliance programs could be explored to maintain market-access as the volume of 'green' spruce exports to the United States is relatively small.
National deregulation is supported by the provinces of Nova Scotia and New Brunswick, as well as key Maritime industry members. Deregulation would also eliminate CFIA surveillance, management, and enforcement efforts, reducing activities to only those required for export certification to maintain international market access for Spruce products. This approach reflects a perspective that BSLB is not a serious pest and will ultimately settle into an ecological balance, much like other forest management concerns. While this would be the likely outcome in the long-term as BSLB continues to spread within Canada, it is considered more feasible to continue regulation in the short term, with ongoing recognition of additional areas in which the pest has established. Regulatory tools (i.e., legislative control) can be effective in slowing the spread of the pest, if applied appropriately and consistently. This is a scientifically supported approach, consistent with the management of other regulated pests in Canada, fits within Canada's international obligations to maintain credibility, and reflects a continued risk-based usage of resources. Being consistent with the management of other forest pests, it also improves predictability and certainty as to the impacts of regulation. Immediate regulation of additional areas where the pest has established will allow for free movement of spruce products within this expanded area, and continue to slow the spread of BSLB to other areas of Canada.
Since national deregulation is not yet fully scientifically supported, it is not clear if provinces other than Nova Scotia and New Brunswick will support it. Although BSLB appears to behave as a secondary pest in Nova Scotia, and has been ranked as presenting a 'low-moderate risk' in the recent NSDNR PRA, there still remain considerable uncertainty about how the pest will behave in other areas of Canada with different climatic zones, fauna and tree stressors.
As with all pest situations, the management and regulation of BSLB will be periodically reviewed subject to pest distribution and current scientific information with consideration of national deregulation as the ultimate goal. Additionally, to support both short-term and long-term goals, activities such as those suggested below could be implemented by stakeholder partners and collaborative groups:
- Implement non-regulatory recommendations such as Best Management Practices
- Increase industry, stakeholder, and public awareness through communication materials and media campaigns, signs, pamphlets
- Manage stand health through silviculture & tree-removal, etc.
- Maintain surveillance program to determine extent of spread
- Maintain trade negotiation efforts to ensure market access
- Support research and development of management tools
Reducing the risks presented by the firewood pathway continues to be an important component of the CFIA's overall strategy. The CFIA continues to update its firewood program to include import requirements and domestic guidelines to reduce risks posed by this pathway. Currently, due to the challenges posed by regulating the movement of firewood within Canada, the CFIA is working with federal, provincial, and private partners to deliver an extensive outreach 'Don't Move Firewood' program that aims to distribute a common message about the dangers posed by inadvertent pest-movement associated with the long-range movement of firewood for commercial distribution, household-heating, or recreational purposes such as camping. CFIA prevents the movement of firewood from regulated pest-areas where this distribution is a concern, for forest pests such as Asian Longhorn Beetle, Emerald Ash Borer, as well as BSLB. However, due to the nature of this commodity distribution, it is not always possible to monitor and restrict every instance of firewood movement.
7.2 Management approach
Maintaining the existing "emergency response" approach on a long-term basis is not feasible, given the continued spread of BSLB, its low to medium pest risk status, and the current resource challenges associated with the regulation of numerous individual infested sites. A responsibly-managed phased approach towards ultimate deregulation of the pest in the future is proposed during which BSLB is regulated within an expanded regulated area as an appropriate interim measure, followed by further expansion when the spread of the pest warrants it, and eventual national deregulation.
While deregulation of BSLB will be the likely outcome in the long-term as it continues to spread within Canada, its presence within central Nova Scotia supports a continued 'slow-the-spread' regulatory approach for the short-medium-term future; however this regulation must accurately reflect its known and current distribution. Continued enforcement of restrictions on the movement of regulated articles will limit the pests artificial spread, thereby continuing to slow the spread of BSLB in Canada. Options available for expanding the BSLB regulated area to reflect its distribution in Nova Scotia include:
- Regulating the eight known infested counties in Nova Scotia (Hants, Colchester, Halifax, Lunenburg, Antigonish, Cumberland, Pictou and Kings) leaving some outlier sites as individually regulated properties. This expansion represents more accurately the contiguous distribution of the pest, and is based on triggers where counties are regulated when either of the following conditions is met:
- Single beetle caught in a trapping-site in more than 1 year, OR,
- Four or more beetles caught in a trapping-site within a year.
- Regulating the province of Nova Scotia in its entirety. This option harmonises with the approach taken by the USA, in regulating all of Nova Scotia for Spruce products.
With either option, the CFIA and partners would continue surveillance activities at the regulated area perimeter to monitor pest distribution, taking into consideration host-distribution and risk factors. The CFIA would also maintain regulatory oversight on product movement from the regulated area, provide electronic communications materials, and, support research on management tools, as part of a collaborative approach to management with partners and stakeholders. In order to ensure that industry logistics operations are not compromised under option a, transport restrictions for regulated articles transiting the regulated area would be based on a "no overnight stopping" approach.
Pros: Expanding the regulated area provides a greater level of protection for the rest of Canada as it would result in a lower risk associated with spruce material moving from areas within Nova Scotia that are currently unregulated, but in which there is a high probability that BSLB populations have already established. Option (a) builds on the previous recommendation by the Science Subcommittee to expand the regulated area to encompass a majority of the additional satellite positive sites, while option (b) harmonises with the US perspective by regulating the entire province of Nova Scotia.
Cons: Maritime industry stakeholders have indicated that any expansion of the regulated area poses logistical problems for movement of materials within Nova Scotia, and may compromise their maritime-exempted position in the upcoming renewal of the softwood lumber agreement (although phytosanitary issues are usually exempted from such discussions). Option (b) also implicates additional areas in Nova Scotia as regulated, even though the pest has not been shown to be established in them yet.
In relation to the phased approach and future expansions of the regulated area, the CFIA would continue to regulate on a county-by-county basis while the distribution of BSLB remains restricted to Nova Scotia. When, and if, it spreads to other provinces, the CFIA will consult with stakeholders on how to continue regulations; county-by-county approach, transitioning to a province-by-province approach, or whether national deregulation would be warranted based on the pest-distribution and any new risk-based information.
7.3 Management recommendation
The CFIA plans to implement the scientifically-supported management approach of continued regulation with expansion of the regulated area to the three known-infested counties in Nova Scotia (option a), with further expansion of the area on a county-by-county or provincial basis, as required, ultimately leading to national deregulation of the pest at a later stage in the future, based on scientific information. This reflects a balanced, phased approach to the long-term management of BSLB and is consistent with the CFIA's approach for other similar pests (e.g. emerald ash borer).
By way of this RMD, CFIA is accepting comments from all interested stakeholders on this proposed approach. Please send in your comments via:
Fax: 613-773-7204 (ATTN to BSLB Management Program c/o Forestry)
Mail: BSLB Management Program c/o Forestry
Plant Biosecurity and Forestry Division
59 Camelot Drive
Ottawa, ON K1A0Y9
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Appendix 1 - BSLB detections in Canada (as of Aug 5, 2014)
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