international trade – Page 13 – Center for Invasive Species Prevention

How many new tree-killing pests can we expect?

Several analyses seek to quantify the risk that new tree-killing pests will be introduced to North America. They use different data sources and assumptions, and reach somewhat different conclusions. But all agree that the risk remains high, and the consequences of such introductions are dire.

I have relied on the Aukema et al. 2010 (see references at the end of the blog) and Haack et al. 2014 studies in past blogs. Aukema et al. 2010 looked at the probable dates of introduction for established insects and pathogens to determine that over 150 years, from 1860 to 2006, damaging forest insect and pathogen species were detected at an average rate of between 0.47 and 0.51 species per year. This translates to one damaging insect or pathogen every 2.1 to 2.4 years. The frequency of detection of high-impact forest pests rose sharply after 1990; beginning that year, detections of high-impact forest pests averaged 1.2 per year, nearly three times the rate of detections in the previous 130 years.

In 2013, 25 million shipping containers entered the U.S. An estimate from more than a decade ago is that wood packaging is used in about half of these containers. Haack et al. (2014) has estimated that 0.1% (1/10^th of 1%) of the wood packaging in more than 12 million shipping containers entering the country each year is infested with quarantine pests. That works out to nearly 13,000 containers harboring pests that probably enter the country each year. That is 35 potential pest arrivals per day.

Leung et al. 2014 concluded that continuing to implement the international standard — ISPM#15 — at the efficacy level described by Haack et al. would result in a tripling of the number of non-native wood-boring insects introduced into the U.S. by 2050.

Koch et al. 2011 have also attempted to determine the current rate of introduction of wood-boring insects. They also sought to evaluate the introduction risk for specific metropolitan areas.

Koch et al. utilized various sources of information about volumes of imports of goods likely to be associated with wood-boring pests (e.g., raw wood and wood products; and stone, metals, non-metalic minerals, auto parts, etc., contained in wooden crates and pallets) to estimate both a nationwide establishment rate of wood-boring forest insect species and the likelihood that such insects might establish at more than 3,000 urban areas in the contiguous US.

They estimated the nationwide rate of introduction of wood-boring pests at between 0.6 and 1.89 forest pest species per year for the period 2001–2010. Even the more conservative estimates points to establishment of a new alien forest insect species somewhere in the US every 2–3 years. If one accepts the ‘‘tens rule’’ – that one out of ten new introductions proves to have substantial effects, then one expects establishment of a significant new pest on average every 5 – 6 years. The authors note that the establishment of at least four ecologically and/or economically significant alien forest insects during the past 20–25 years – emerald ash borer, Asian longhorned beetle, Sirex woodwasp, and redbay ambrosia beetle – fits the model’s conclusion. [All of these pests are described in the Gallery of Pests posted here.]

The Aukema et al. estimate for introductions of “high impact” pests during the period after 1990 – 1.2 per year – is in the middle of the Koch et al. estimate for wood-borers, but higher than the Koch et al. estimate for “significant” pests.

Koch et al. estimated a lower rate of introductions between 2010 and 2020 – between 0.36 and 1.7 species per year. The Haack et al. and Leung et al. analyses would seem to contradict this expectation. Also, the findings of Seebens et al. (see my blog from earlier this week) contradicts any expectation that introductions will soon decline as a result of depletion of the pool of possible pests in origin countries.

Koch et al. analyzed data on imports of relevant commodities from all source regions to determine the introduction risk for 3,126 urban areas in the country. The urban area at greatest risk was Los Angeles–Long Beach–Santa Ana, California. The predicted introduction rate for both 2010 and 2020 for this metropolis was establishment of a new alien forest insect species every 4–5 years. The port of New York-Newark came in second, with a predicted establishment rate of one every 8–9 years. Houston ranked third; its predicted establishment rate was one every 13–15 years. All other urban areas were at substantially lower risk – a new introduction every 24 years.

Looking ahead to the decade 2010 to 2020, Koch et al. found that three California metro areas – Los Angeles–Long Beach–Santa Ana; San Diego; and Riverside-San Bernardino – would be exposed to increased establishment rates driven by the growth of imports from Asia.

Risk To Canada

Yemshanof et al. 2011 applied the Koch et al. methodology to evaluate the risk to Canada. Reflecting the lower volume of imports entering Canada compared to the U.S., they found a lower nationwide entry rate for Canada – 0.338 new forest insect species per year vs. the Koch et al. estimate of 1.89 for the U.S. Evaluating individual urban areas, they found the greatest risks to the Greater Toronto and Greater Vancouver areas. Moderate-sized cities near ports, major markets, or U.S.-Canada border crossings – transportation hubs – were also at heightened risks.

Canada as Pest Pathway to U.S.

Yemshanof et al.’s model indicates that 8% of all tree pests entering the U.S. as estimated by Koch et al., come through goods transshipped through Canada. The risk is highest to the Pacific Coast states since they are the most likely to receive Asian goods transiting through Canada. Note that the U.S. and Canada have proposed requiring that wood packaging originating in one of the countries and shipped to the other should be included under the ISPM#15 regulation. However, APHIS was unable to adopt this regulation under the Obama Administration, and such an action seems even less likely under the Trump Administration.

Neither study included plant imports, which are another very important pathway for introduction of tree-killing pests, especially pathogens.

SOURCES

Haack RA, Britton KO, Brockerhoff EG, Cavey JF, Garrett LJ, et al. (2014) Effectiveness of the International Phytosanitary Standard ISPM No. 15 on Reducing Wood Borer Infestation Rates in Wood Packaging Material Entering the United States. PLoS ONE 9(5): e96611. doi:10.1371/journal.pone.0096611

Koch, F.H., D. Yemshanov, M. Colunga-Garcia, R.D. Magarey, W.D. Smith. 2011. Potential establishment of alien-invasive forest insect species in the United States: where and how many? Biol Invasions (2011) 13:969–985

Leung, B., M.R. Springborn, J.A. Turner, E.G. Brockerhoff. 2014. Pathway-level risk analysis: the net present value of an invasive species policy in the US. The Ecological Society of America. Frontiers of Ecology.org

Yemshanov, D., F.H. Koch, M. Ducey, K. Koehler. 2012. Trade-associated pathways of alien forest insect entries in Canada. Biol Invasions (2012) 14:797–812

Posted by Faith Campbell

We welcome comments that supplement or correct factual information, suggest new approaches, or promote thoughtful consideration. We post comments that disagree with us — but not those we judge to be not civil or inflammatory.

Alien species introductions — going up!

trade transports many invasive species

Containers at Long Beach, California; courtesy of the Port Authority

In an article published recently in Nature Communications , Hanno Seebens and 44 coauthors show that the rate of new introductions of alien species has risen rapidly since about 1800 – and shows no sign of slowing down. See a summary of the article with revealing graphs here .

Through analysis of a database covering 45,813 first records of 16,926 alien species established in 282 distinct geographic regions, the authors determined that the number of new species reports reached a maximum of 585 in 1996 (or an average of more than 1.5 sightings per day).

Of course, whether a species’ introduction is detected depends on a variety of factors. One of the most important is the species’ impact – or lack thereof! – on economically important resources – this determines whether the species gets noticed. Furthermore, detection usually happens some time after a species’ actual introduction. And, regardless of factors motivating human attention, some types of species are more easily detected than others. All these factors skew the findings. Because many introductions are not detected, Seebens et al. note, their data underestimate actual introductions.

The authors found that the adoption of national and international biosecurity measures during the 20th century have slowed introductions – but they are not yet sufficiently effective. Most notably, numbers of reported new introductions of fish and mammals have decreased since the early 1950s. Of course, introductions of these taxa are usually the result of deliberate decisions, usually by authorities. It is encouraging that authorities appear to be getting the message that adding new species to an ecosystem is a risky enterprise.

Japanese honeysuckle; courtesy of Bugwood.org

However, not all deliberate introductions have been curbed. Seebens et al. were surprised to see that vascular plant species introductions remained at such a high rate throughout the 20^th century. Introductions of birds and reptiles also continue to rise, largely as pets in countries with strengthening economies.

For those plants and animals that are introduced primarily accidentally as stowaways on transport vectors or contaminants of commodities (e.g., algae, insects, crustaceans, molluscs and other invertebrates), Seebens et al. found a strong correlation between their spread and the market value of goods imported into the region of interest.

Having noted that almost all biosecurity efforts are not yet slowing introductions adequately, Seebens et al. point to New Zealand as the exception. That country adopted the Biosecurity Act in 1993 and the Hazardous Substances and New Organisms Act in 1996.

Although 20 years is a short period to gauge a policy’s efficacy – especially given time lags in detecting introductions – Seebens et al. say the stringent new policy appears to be succeeding. They found a significant decline in the number of new alien plants detected in New Zealand since the 1990s. New Zealand’s laws rely on a “white list” of permitted species rather than the more usual “black list” of prohibited species. New Zealand requires a risk assessment before a decision is made to allow any new species to be brought into the country.

Of course, such an approach does not apply easily to the taxa most often introduced as unintended hitchhikers on, or as contaminants of, imported goods, packaging, or transport vehicles – such as tree-killing insects and diseases. The paper notes that existing biosecurity regimes have not slowed down the accumulation of alien species introductions overall, but especially those arriving mainly accidentally, such as invertebrates and pathogens.

As a consequence, Seebens et al. expect that the numbers of new alien species will continue to increase.

I have previously blogged about other studies that show continuing introductions of forest pests and other specific taxonomic groups. See blogs about (1) 2014 IUCN report on invasive species threats to World Heritage sites; (2) IUCN analysis of red-book-listed species – causes of endangerment; (3) rate of new plant pests being detected in US; (4) Jung et al. on Phytophthoras in Europe; (5) Zamir’s critique of international the phytosanitary system; (6) Klapwjik et al. on European efforts to strengthen regulations governing movement of living plants; (7) ISPM#15 11^th anniversary.

Other recent studies have also examined the bioinvasion situation for the whole Earth or major regions. Liebhold et al. 2016 studied insect assemblages in 20 regions around the world. They found that which insect orders are present in a particular region differs completely depending on whether one is looking at native or at nonindigenous assemblages. The authors believe that difference is largely caused by the varying probability that an insect taxon can take advantage of one or more high-volume invasion pathways – such as trade in agricultural products, movement of plants by international travelers, shipments of stored grain, trade in living plants, hitchhiking (e.g. on the outside of shipping containers) and wood packaging. Pathway association appeared to be more important than insects’ life-history traits, which affect their ability to establish in a new ecosystem.

Maartje J. Klapwijk and several colleagues note that growing trade in living plants and wood products has brought a rise in non-native tree pests becoming established in Europe. The number of alien invertebrate species has increased two-fold since 1950; the number of fungal species has increased four-fold since 1900.

Jung et al. (2015) studied the presence of Phytophthora pathogens in nurseries in Europe. They found

Two-thirds of the Phytophthora taxa detected in European nurseries by the present study were unknown to science before 1990.
None of the 59 putatively exotic Phytophthora taxa detected in the present study had been intercepted at European ports of entry.
Spread of the quarantine organism ramorum has not been halted despite the presence of strict quarantine regulations.

I will post a blog examining introduction rates for tree-killing insects and pathogens specifically in the near future. In the meantime, see the published studies listed below as well as my earlier blogs and fact sheets posted here .

Aukema, J.E., B. Leung, K. Kovacs, C. Chivers, K. O. Britton, J. Englin, S.J. Frankel, R. G. Haight, T. P. Holmes, A. Liebhold, D.G. McCullough, B. Von Holle.^. 2011. Economic Impacts of Non-Native Forest Insects in the Continental United States PLoS One September 2011 (Volume 6 Issue 9)

Aukema, J.E., D.G. McCullough, B. Von Holle, A.M. Liebhold, K. Britton, & S.J. Frankel. 2010. Historical Accumulation of Nonindigenous Forest Pests in the Continental United States. Bioscience. December 2010 / Vol. 60 No. 11

Liebhold, A.M., T. Yamanaka, A. Roques, S. Augustin, S.L. Chown, E.G. Brockerhoff, P. Pysek. 2016. Global compositional variation among native and nonindigenous regional insect assemblages emphasizes the importance of pathways. Biological Invasions (2016) 18:893–905

Lovett, G.M., M. Weiss, A.M. Liebhold, T.P. Holmes, B. Leung, K.F. Lambert, D.A. Orwig , F.T. Campbell, J. Rosenthal, D.G. McCullough, R. Wildova, M.P. Ayres, C.D. Canham, D.R. Foster, S.L. LaDeau, and T. Weldy. 2016. Nonnative forest insects and pathogens in the United States: Impacts and policy options. Ecological Applications, 0(0), 2016, pp. 1–19. DOI 10.1890/15-1176.1

Posted by Faith Campbell

A Tale of Two Pests: APHIS’ Response Contrasts Greatly

spotted lanternfly

Holly Raguza, Pennsylvania Department of Agriculture

I have not written previously about two insects that threaten fruit and forest trees in the U.S. – the spotted lanternfly (Lycorma delicatula) and the velvet longhorned beetle (Trichoferus campestris). APHIS has adopted strangely – and unexplained – different approaches to the two.

Spotted Lanternfly – Pennsylvania Jumps In; APHIS Provides the Funding

The spotted lanternfly (Lycorma delicatula) was first detected in southeast Pennsylvania in autumn 2014. It is native to China, India, and Vietnam. What was known then about its host range came from experience in Korea, where it had also been introduced. Officials were alarmed because the lanternfly is considered a pest of grapes and peaches – both are major crops in Pennsylvania (Spichiger Update; see reference below).

Currently, outbreaks of the spotted lanternfly are in 74 municipalities in six counties in the southeastern part of the Commonwealth – covering a total of 829 square miles. In the more than two years since its detection, the spotted lanternfly has not spread to the rest of the Commonwealth or to other states. Authorities therefore believe that the state’s quarantine is having an impact (Spichiger Update & pers. comm.).

Pennsylvania’s authorities believe the lanternfly utilizes about 80 species of plants, especially during the early stages of its development. A monitoring program managed by Dr. Gregory Setliff of Kutztown University (see reference below) has developed a list of 24 putative hosts – including maples, birches, hickories, dogwoods, beech, ash, walnuts, tulip tree, tupelo, sycamore, poplar, peaches and plums, oaks, willows, sassafras, basswood, and elms. Setliff also found that the lanternfly will penetrate into woodlands; it does not stay on the edges.

Adults strongly prefer the widespread invasive species tree of heaven (Ailanthus altissima). In fact, it might be necessary for adults to feed on Ailanthus before laying their eggs. However, oviposition can occur on not just a wide variety of plants but also nearly any hard surface (Spichiger).

Officials are optimistic that an approach using trap trees will eradicate the spotted lanternfly. They remove most Ailanthus, then apply a systemic pesticide to the remaining trees to kill adult lanternflies when they feed (Spichiger).

Fortunately, this insect is conspicuous. As a result, 90% of citizen reports of sightings have proven to be accurate (Spichiger). This contrasts greatly with phytosanitary officials’ experience with Asian longhorned beetle, emerald ash borer, and other tree-killing pests.

Scientists in both Pennsylvania and China are looking for natural enemies.

The entire program in Pennsylvania has been funded through a series of Farm Bill grants from APHIS (Spechiger pers. comm.). These began in FY2016, right after the 2014 detection. By FY2017, Farm bill funding totaled nearly $2 million; it went to a myriad of entities to: study lanternfly lifecycles and host preferences; find possible biocontrol agents and chemical treatments; and – especially – for outreach and education. Nearly $1.6 million of these funds went to state agencies in Pennsylvania.

Velvet Longhorned Beetle — States Limp Along; APHIS Support Minimal

velvet longhorned beetle

Christopher Pierce, Bugwood

In contrast to the spotted laternfly, populations of the velvet longhorned beetle (VLB Trichoferus campestris) appear to be more long-standing and more widely spread. It was first found in 2010 in Utah. Now, it has been detected 15 separate times in Quebec and 11 U.S. states, according to Wu et al. 2017 and websites listed below. States specifically mentioned by sources include Illinois, Minnesota, New Jersey, New York, Ohio, Pennsylvania, and Rhode Island. Most are of single or a few beetles – although detections are sometimes repeated over several years – e.g., in Minnesota.

In contrast, the outbreak in Utah appears to be established and growing. The number of beetles detected has exploded from 4 in 2010 to 1,863 in 2015 .

Like so many other invaders, this beetle is known to be native to East and Central Asia.

The host range is still being studied. Hosts are thought to include more than 40 genera, including apple; cherry and peach; maple; birch; mulberry and paper mulberry; beech; ash; honey locust; mountain ash; willow; and cut wood of spruce and pine.

Like other woodborers, the velvet longhorned beetle has often been intercepted in wood packaging (see my earlier blogs. There have been 29 interceptions of the Trichferous genus over 3 years. Some of the newly established populations – such as Utah’s outbreak – are tied to specific shipments in which wood packaging was insect-infested (Wu et al. 2017).

VLB has also been detected in imported rustic furniture – probably because the beetle is apparently much more tolerant of tunneling in dry wood than other Cerambycids. In some pieces, insect activity was not detected until 18 months after the furniture was purchased. In 2016 a Minnesota homeowner discovered a beetle emerging from bark-covered furniture that she had purchased more than a year earlier. Furniture from this shipment was shipped to at least 10 other states [Mark Abrahamson, Minnesota Department of Agriculture, pers. comm. February 16, 2017]. The Minnesota Department of Agriculture, APHIS, and other State departments of Agriculture are working with the furniture seller to recover and destroy all infested furniture.

Detection of the velvet longhorned beetle has been hampered by the absence of a good lure for traps. Dr. Ann Ray of Xavier University in Ohio has isolated and identified a possible lure but needs another field season to determine the right amount of pheromone for each trap. While Dr. Ray’s earlier work had been funded by APHIS through its Section 10007 program, APHIS chose not to fund the final stage of testing in the FY2017 Farm Bill grant program. Indeed, no VLB programs were funded this year.

This contrasts sharply with APHIS’ continued engagement with the spotted lanternfly.

The extent of damage to fruit trees caused by the velvet longhorned beetle has been difficult to determine (Ray; see reference below). Perhaps for this reason, APHIS has not adopted an official stance on whether the beetle is “established” in the United States. Thus, five years after the insect was detected for a second year in Utah, the agency cannot make up its mind how great the threat is and what the agency’s response should be.

If the velvet longhorned beetle turns out to be highly damaging, eradicating it will have become increasingly difficult during the years that APHIS has pondered what to do.

SOURCES

Ray, Annie. Evaluation of lure and trap design for monitoring the velvet longhorned beetle Trichoferus campestris. XXVIII USDA Interagnecy Research Forum on Invasive Species January 10 -13, 2017.

Setliff, Gregory P. Investigating the host range of the spotted lanternfly (Lycorma delicatula) in southeastern Pennsylvania. XXVIII USDA Interagnecy Research Forum on Invasive Species January 10 -13, 2017.

Spichiger, Sven-Erik. Pennsylvania Department of Agriculture. Update on spotted lanternfly program in Pennsylvania. XXVIII USDA Interagnecy Research Forum on Invasive Species January 10 -13, 2017.

Wu,Y., N.F. Trepanowski, J.J. Molongoski, P.F. Reagel, S.W. Lingafelter, H. Nadel1, S.W. Myers & A.M. Ray. 2017. Identification of wood-boring beetles (Cerambycidae and Buprestidae) intercepted in trade-associated solid wood packaging material using DNA barcoding and morphology

Posted by Faith Campbell

New Secretary of Interior Pledges to Support Invasive Species Efforts — Let’s Ask USDA Secretary to do the Same!

Interior Secretary nominee Ryan Zinke

During his confirmation hearing Ryan Zinke, nominated to be the new Secretary of Interior, committed to several senators that he would explore ways to better manage invasive species on federal lands – especially in National parks – and to strengthen the National Invasive Species Council (NISC).

Mr. Zinke is currently a Congressional Representative from Montana. Senator Debbie Stabenow (MI) pressed him on invasive species issues during the hearing, focusing on the threat to the Great Lakes of carp and other aquatic species. Also, Senators Al Franken (MN), Joe Manchin (WV), and Mazie K. Hirono (HI) asked about invasive species in written questions submitted to the nominee.

Mr. Zinke answered most questions the same way: He shares the Senator’s concern, especially since Montana has significant invasive species problems. Also, he thinks it is critical that federal land managers be encouraged and empowered to be good neighbors in controlling invasive species in cooperation with adjacent private land owners. … Specifically he wants to explore ways to implement the Early Detection Rapid Response Framework adopted by NISC in 2016.

* Sen. Franken included a single question on bioinvaders among a long list of questions on other topics. He mentioned the emerald ash borer as one example of a damaging invader in Minnesota. Senator Franken asked Mr. Zinke:

1) what steps he would take to enhance invasive species control on public lands

See paragraph above for Mr. Zinke’s answer.

2) whether he would enforce the Lacey Act and explore ways to strengthen it.

Mr. Zinke said he would enforce the law. He is aware that there is broad bipartisan frustration with the lack of an efficient process for listing injurious species under the Act. He would ask the Fish and Wildlife Service to recommend ways to improve its implementation. If legislative changes might be helpful, he would be pleased to have that conversation with the Congress.

* Sen. Manchin’s first question (!) asked how Mr. Zinke might strengthen NISC to help manage invaders across multiple types of land ownership. See Mr. Zinke’s frequent reference to his Montana experience above for his answer.

* Sen. Hirono asked five questions pertaining to invasive species! Her first question concerned steps to protect National parks (especially in Hawaii) from bioinvasion. Here, Mr. Zinke gave his usual response but added: “I am especially concerned that Hawaii’s unique flora and fauna are vulnerable to invasive species. I would not want to see invasive species push any of these unique plants and animals onto the Endangered Species list. Once confirmed, I will ask the National Park Service to present me with options for better protecting our national parks from invasive species.”

Ms. Hirono also asked about strengthening NISC. Mr. Zinke responded as follows: “…, I will explore ways to improve the operations of the National Invasive Species Council, and actively engage with the Secretaries of Commerce and Agriculture to get off to a strong start on this issue. … We also need to create a more effective linkage between the National Invasive Species Council policy operation in Washington, DC, and the on the ground federal land managers across the country who deal with invasive species on a daily basis…”

Also, Sen. Hirono asked for Mr. Zinke to help Hawai`i and other U.S. Pacific islands to counter the spread of invasive species through movement of military equipment. Mr. Zinke said he would work to enhance coordination with the Department of Defense and the Pacific island communities to reduce the risks posed by invasive species. … explore how we may implement the recent framework for early detection and rapid response …

Mr. Zinke also promised to work with Senator Hirono on several issues under Interior jurisdiction that are priorities for Hawai`i, among them invasive species.

What We Should Ask the new President & Congress to Do re: Invasive Species

While there are many opportunities for the Congress to strengthen U.S. invasive species programs (see my blog from December 31 here, the most important activity NOW is the confirmation of Sonny Perdue as Secretary of Agriculture. Contact your Senators and urge them to ask Governor Perdue how he will address invasive species challenges.

USDA Secretary nominee Sonny Perdue

Possible questions:

Q: How serious do you think is the threat to American natural resources from invasive (non-native) insects, pathogens, and plants? Can you suggest steps you would take to strengthen the efforts of the Animal and Plant Health Inspection Service (APHIS) aimed at controlling introduction and spread of such bioinvaders into the United States?

Q: The principal legal authority for preventing introductions of invasive plants and plant pests is the Plant Protection Act. The PPA provides strong authority but its implementation has been hampered by internal USDA decisions. How would you ensure that the Department corrects these problems and actively enforces its regulations aimed at ensuring the health and productivity of America’s plant resources?

In recent years, more than 20 previously undetected plant pests have been detected in the country each year. Hundreds of shipments of goods entering the country each year contain plant pests. What strategies would you promote to reduce the introduction, spread, and impacts of invasive species?

Q: Given the ever-tightening budget allocated to agencies responsible for addressing invasive species threats, what steps would you take to ensure that our country does not suffer waves of new invasions?

If you have a working relationship with your Senators and believe they understand the invasive species issue fairly well, you might want to suggest more detailed questions:

Q: As you know, the Animal and Plant Health Inspection Service (APHIS) is responsible for preventing introduction and spread of plant pests.

In some cases, APHIS has been hesitant to use its authority to penalize importers which routinely receive shipments that violate plant pest (phytosanitary) regulations. [You might cite my blog from last week which illustrates examples pertaining to wood packaging.] Will you instruct APHIS to use its legal authority to impose civil penalties to deter continuing violations?

Trying to prevent pest introductions by increasing the percentage of shipments that are inspected visually will not be effective in many cases. This is true especially with regard to one of the most important pathways by which plant pests are introduced – imports of living plant material such as nursery stock. APHIS began updating its regulations governing plant imports nearly four years ago, but the proposed new regulations have been not been finalized. Will you look into the reasons for delay and take steps to update these regulations to focus on pathway cleanliness rather than continue to rely on ineffective visual inspections?

Q: Urban forests across the country are under threat from a growing number of non-native or introduced insect pests. Examples include the emerald ash borer – now found in 27 states; Asian longhorned beetle – which threatens a large proportion of urban trees across the country; and polyphagous and Kuroshio shot hole borers – killing many trees in southern California.

Urban forests are at particularly high risk of infestation by non-native pests because they are growing near ports and other transportation hubs where such pests are first introduced. Furthermore, each individual tree in an urban setting provides important benefits in the form of shade, moderation of storm water runoff, abatement of air pollutants, enhanced property values, and neighborhood amenities.

Will you fully utilize the authorities under the Plant Protection Act to help ensure the health and productivity of America’s urban forests?
[If you have not already suggested the questions outlined above re: wood packaging and other pathways, you might suggest them in this context.]

The Secretary of Agriculture also oversees the Forest Service. Pertinent questions:

Q: Invasives are as great a threat to eastern forests as wildfires are in the West. Despite the growing damage and ecological destruction we are witnessing the budgets for research on strategies to minimize these bioinvaders’ impacts are actually falling. How will you work to provide solutions to this quandary?

As I said in my blog at the end of December, what is missing is a political demand for action – and support for necessary staff and funding. Agencies under the secretaries of Agriculture and Interior bear most of the responsibility for managing invasive species. As long as these officials are not being pressed by key Congressional committees, the media, and key stakeholders to take more aggressive and effective action to curtail species introductions and suppress established populations of bioinvaders, they will continue to focus their attention on issues that do generate these kinds of political pressure.

Posted by Faith Campbell

Wood Packaging – Again! 11 years after ISPM#15, problems persist …

ALB pupa; Thomas B. Denholm, New Jersey Department of Agriculture; bugwood.org

As I have noted in earlier fact sheets and blogs, wood packaging (crates, pallets, etc.) has been a major pathway for introductions of highly damaging wood-boring pests since at least the early 1990s. (See Figure 2a in Aukema et al. 2010; reference given at end of blog.)

This rise in introductions followed the rapid increase in use of shipping containers – as described in Levinson’s book The Box (reference below). Levinson notes that shipping capacity increase fourfold during the decade of the 1970s, reaching 10 million tons in 1980. (See also my blog from August 2015 here). A second factor was the U.S. opening trade with China in 1979. Since in those years – before establishment of more sophisticated detection tools – a pest was often present for close to a decade before being detected, it is not surprising that detections of woodboring pests began their rise around 1990.

February 2017 marks 11 years since the international standard (ISPM#15) was put into effect by the United States and 17 years after the U.S. and Canada began requiring China to treat its wood packaging. Nevertheless, numerous shipments containing wood packaging that does not comply with the regulations continue to arrive at our borders – and to bring pests.

A study by scientists and economists (Haack et al. 2014; reference below) analyzed detection data from the U.S. and other countries in order to calculate the reduction in pest risk associated with wood packaging following adoption of ISPM#15. They concluded that one tenth of one percent of the wood packaging entering the U.S. after adoption of ISPM#15 still contained a tree-killing pest. This sounds like a small risk. However, the U.S. imported approximately 25 million shipping containers in 2013 – and presumably similar numbers in more recent years. It has been estimated in the past that wood packaging is used in just over half of these containers. Therefore, even if merely 1/10^th of 1% of the wood packaging in these shipments contained a tree-killing pest, 13,000 containers harboring pests probably enter the country each year. That is 35 potential pest arrivals each day.

Interception records compiled by USDA APHIS and the DHS Bureau of Customs and Border Protection clearly show that wood packaging infested with pests continued to arrive in recent years – including in 2016.

Over a period of seven years – Fiscal Years 2010 through 2016 – CBP detected more than 20,700 shipments with wood packaging that did not comply with ISPM#15. While most of the non-compliances represented wood packaging that lacked the required mark showing treatment per ISPM#15, in nearly 5,000 cases the wood packaging actually harbored a pest in a regulated taxonomic group (see Customs presentation at the Continental Dialogue here).

Customs inspectors at 11 ports (listed at end of blog) have been sending intercepted wood packaging containing insect larvae to APHIS for study. APHIS has also sent to me its record of interceptions for the period FYs 2011 – 2016.

The APHIS interception database contained 2,547 records for insect detections. The insects belonged to more than 20 families. Families with the highest numbers of detections were Cerambycids – 25% of total; Curculionidae – 23% (includes Dendroctonus, Ips, Orthotomicus, Scolytinae, Xyleborus, Euwallacea); Scolytidae – 17% (includes true weevils such as elm bark beetles); Buprestids – 11%; and Bostrichidae – 3%. Not all of the insects in these groups pose a threat to North American plant species.

piece of wood packaging with Cerambycid larva; detected in Oregon

The samples sent by CBP to APHIS are limited largely to the families Cerambycidae (the family containing the Asian longhorned beetle) and Buprestidae (the family containing the emerald ash borer). This dataset contains 1,068 insects, obtained over the period April 2012 through August 2016 from 786 separate interceptions of non-compliant wood packaging. The sample is not from a random set of ports – four of the seven entry points are on the Mexican border, and the proportion was even higher in the early years of the study.

The APHIS interception database reports pests detected in wood packaging from dozens of countries. The countries of origin with the highest numbers of shipments detected to have pests present were Mexico, China, Italy, and Costa Rica. These numbers reflect in part import volumes. The U.S. imports huge volumes of goods from both Mexico and China. (Our second largest trade partner is Canada; the U.S. and Canada have exempted wood packaging moving between the two countries from the requirement that it comply with ISPM#15. Neither country inspects wood packaging from the other country at even the low rate of inspection applied to wood packaging coming from Mexico or overseas.)

The CBP-APHIS database includes pests found in wood packaging from 39 countries, including 212 shipments from Europe; 130 shipments from Asia; and 341 shipments from the Americas – almost exclusively Mexico.

APHIS analysts point out that the pests from Mexico might pose a lower risk since some proportion of them are probably species shared between our two countries. (However, several woodborers from Mexico are killing trees in the U.S. – e.g., goldspotted oak borer, walnut twig beetle, and soapberry borer. These species are described briefly here. These insects were probably introduced to vulnerable parts of the U.S. in firewood rather than wood packaging.)

As always (see the briefs here as well as various articles by Haack and Cavey), imports of heavy objects are associated with wood packaging found to be infested with insects: metal and machine parts, tiles, decorative stone. Imports of fruits and vegetables rank high because of the large number of interceptions in wood packaging from Mexico.

Comparing the estimate by Haack et al. 2014 with the CBP data indicates that Customs is detecting about 6% of all pest-infested shipments. I do not believe that increasing the inspection workforce and effort will result in substantial improvement in this rate.

On average, 26% of infested wood pieces detected by CBP were found in wood that had been treated according to ISPM#15 requirements (if we believe the ISPM#15 stamp on the wood). Does this indicate fraud? Or is the problem accidental misapplication of the treatments? Or are the treatments less effective than hoped? APHIS researchers have found that larvae from wood subject to methyl bromide fumigation were more likely to survive to adulthood than those intercepted in wood that had been heat treated. Does this indicate that methyl bromide fumigation is a less effective treatment?

CBP staff reported that only about 30 import shipments (out of nearly 21,000 shipments found to be in violation of ISPM#15 requirements) have received a financial penalty. CBP staff cite two reasons for the low penalty rate:

USDA policy requires that an importer be caught 5 times in a year with non-compliant wood packaging before authorizing a fine; and
APHIS has not designated SWPM as a high-risk commodity

What Can Be Done to Slow or Eliminate this Pathway?

Our goal should be to hold foreign suppliers responsible for complying with ISPM#15. One approach is to penalize violators. APHIS and Customs might

Prohibit imports in packaging made from solid wood (boards, 4 x 4s, etc.) from foreign suppliers which have a record of repeated violations over the 11 years ISPM#15 has been in effect (17 years for exporters from Hong Kong & mainland China). Officials should allow continued imports from those same suppliers as long as they are contained in packaging made from other types of materials, including plastic, metals, fiberboards …

Fine an importer for each new shipment found to be out of compliance with ISPM#15 in cases when the foreign supplier of that shipment has a record of repeated violations.

There would need to be a severe penalty to deter foreign suppliers from simply changing their names or taking other steps to escape being associated with their violation record.

At the same time, the agencies should work with NGOs and importers to promote creation of an industry certification program that would recognize and reward importers who have voluntarily undertaken actions aimed at voluntarily exceeding ISPM#15 requirements so as to provide a higher level of protection against invasive species that would otherwise potentially be introduced into the United States.

What You Can Do

Tell your member of Congress and Senators that you are worried that our trees are still being put at risk by insects arriving in wood packaging. Ask them to urge the new Secretary of Agriculture (Sonny Perdue, former governor of Georgia) to take the actions outlined above in order to curtail introductions of additional tree-killing pests.

Talk to your friends and neighbors & civic organizations about the threat to our trees. Ask them to join you in communicating these concerns to their Congressional representatives and Senators.

Write letters to the editors of your local newspaper or TV news station.

Use your knowledge about pests threatening trees in your state or locality in your communications!

Ports that have sent specimens to APHIS lab: Seattle, Long Beach, San Diego, Laredo, Hildago, Houston, Miami, Port Everglades, Chicago, Detroit

References

Haack, R. A., K. O. Britton, E. G. Brockerhoff, J. F. Cavey, L. J. Garrett, M. Kimberley, F. Lowenstein, A. Nuding, L. J. Olson, J. Turner, and K. N. Vasilaky. 2014. Effectiveness of the international phytosanitary standard ISPM no. 15 on reducing wood borer infestation rates in wood packaging material entering the United States. Plos One 9:e96611.

Levinson, M. The Box: How the Shipping Container Made the World Smaller and the World Economy Bigger Princeton University Press 2008

Posted by Faith Campbell

The New Year – Where We Are & What Needs to be Done

dying ash tree, Fairfax County, Virginia; photo by F.T. Campbell

According to Aukema et al. 2010 (see references at the end of this blog), by the first decade of the 21^st Century, the number of non-native insects and pathogens damaging our forests had risen to at least 475. Sixty-two of the insects, and all of the 17 pathogens, were judged to have “high impact”, with both economic and ecological ramifications. More than 181 exotic insects that feed on woody plants are established in Canada (USDA APHIS 2009). Especially hard-hit is the eastern deciduous broadleaf forest — there is an exotic pest threat to nearly every dominant tree species in this ecosystem type.

The situation is actually worse than this article and others based on it depict. Aukema et al. 2010 did not include several highly damaging forest pests that are native to regions of North America (e.g., goldspotted oak borer, thousand cankers disease); nor did they include pests on U.S. islands, such as `ohi`a rust and Erythrina gall wasp in Hawai`i. Aukema et al. 2010 also did not include pests that attack palms or cycads – which are significant components of some ecosystems on the continent as well as on America’s tropical islands. Finally, some invaders have come to our attention since the database on which these authors relied was compiled, e.g., polyphagous and Kuroshio shot hole borers and the rapid ohia death pathogen. (For a list of pests detected since 2003, see page 7 of Fading Forests III, available here; this list was compiled in 2014, so it does not include the most recently detected pests, such as rapid ohia death. For descriptions of most invaders discussed in this blog, go here.)

Of course, more important than numbers are impacts. Lovett et al. 2016 provide a summary of those impacts … but let’s get specific. Note that some of these species occupy wide ranges; it is not only the narrow endemics that are under threat.

Several tree species are severely depleted throughout their ranges: American chestnut, Fraser fir, Port-Orford cedar, butternut, Carolina hemlock, redbay and swamp bay, cycads on Guam
Other species or genera are already severely reduced in significant portions of their ranges and the causal agents are spreading to the remaining sanctuaries: whitebark pine.
In some cases, the causal agent has not yet spread, but threatens to: `ohi`a.
Some tree or shrub taxa are under severe attack across much of their ranges: ashes, eastern hemlock, American beech, dogwoods, tanoak, viburnums …

Many of America’s 300 species of oak face a variety of threats:

in the East, European gypsy moth, oak wilt, and – in some areas – winter moth;
in the South, oak wilt and Diplodia;
on the West coast, sudden oak death, goldspotted oak borer, the polyphagous and Kuroshio shot hole borers, Diplodia, and foamy bark canker.

(For more about threats to oaks, see my blog from last April.)

Other threats are – so far – confined to relatively small areas, but they could break out. These include the multi-host insects Asian longhorned beetle; polyphagous and Kuroshio shot hole borers; and spotted lanternfly. Tree genera containing species at risk to one or more of these insects include maple, elm, willow, birch, sycamore, cottonwood and poplar, sweet gum, oak. Only ALB and the lanternfly currently are the focus of federal and state programs aimed at eradication or containment. The widespread invasive tree, Ailanthus or tree of heaven, could support spread of at least the polyphagous shot hole borer and spotted lanternfly.

Of course, additional pests are likely to be introduced (or detected) in the future. Known threats include the various Asian subspecies of gypsy moth and ash dieback (Hymenoscyphus fraxineus – previously called Chalara fraxinea). If history is any guide, we are likely to be surprised by a highly destructive invader that we have either never heard of or dismissed based on its behavior elsewhere. See my earlier blogs for discussions of what should be done to reduce the introduction risk associated with wood packaging and imports of living plants.

What Should We Do?

2017 brings a new Administration and a new Congress. At a minimum, we need to educate all these decision-makers about both the high costs imposed by tree-killing insects and pathogens and effective strategies to minimize those costs. How will our concerns be received? We don’t know yet.

We might have opportunities arising from the skeptical attitude toward trade voiced during the campaign. Will newly elected or appointed agency and Congressional staffers be open to re-considering the plant health threats associated with international trade? On the other hand, will mainstream agriculture’s traditional strong support for exports continue to overwhelm calls to strengthen phytosanitary measures? Even if our message about risks associated with trade gains a hearing, will officials be willing to consider more rigorous regulations? Or higher funding levels for agencies responsible for plant pest prevention and response?

I hope you will join the Center for Invasive Species Prevention and others in coordinated efforts to take these messages to the next Secretary of Agriculture (who has not yet been named!) and key members of the Senate and House of Representatives. Opportunities in the Congress include Senate confirmation of the new Secretary and the three Under Secretaries that oversee APHIS, USFS, and ARS; annual appropriations bills; and early consideration of possible amendments to the Farm Bill (which is due for renewal in 2019).

See my post from a week ago for more suggestions for how Congress could improve U.S. invasive species management programs.

Expect to hear from me often in the coming year!

SOURCES

U.S. Department of Agriculture, Animal and Plant Health Inspection Service. 2009. Risk analysis for the movement of SWPM (WPM) from Canada into the US.

Posted by Faith Campbell

Invasive insects cause tens of billions in damage

Formosan subterranean termite damage to a house in New Orleans; observed by Ed Freytag & Alan Lax; photo by Scott Bauer, USDA Agricultural Research Service; bugwood.org

A recent study documents the high costs imposed by invasive insects worldwide. The study, by Bradshaw et al. (source with link is at the end of this post) concluded that invasive insects cause at least $77 billion (US) in damage every year. This figure includes costs of $70 billion in estimates of damaged goods and service; and $6.9 billion in associated health costs.

What is more, this figure is “grossly underestimated” for a number of reasons:

There were few studies providing cost estimates. The authors started by reviewing more than 700 articles, but found that only 158 yielded usable economic estimates.
Most of the studies applied to North America and Europe; much of the globe is not included.
Ecosystem services eroded by invasive pests are rarely quantified.
The health cost estimate does not include the impact of malaria (in most areas, the vector is native rather than invasive), the Zika virus, or economic losses in tourism or productivity (these latter were too difficult to calculate).

While the most destructive of the insects identified in the reports was the Formosan subterranean termite, Bradshaw et al. question some of the economic data included in the single report on the termite. The most damaging insect for which they found “reproducible” economic estimates is the diamondback moth, a voracious consumer of cruciferous crops worldwide.

Other invasive insects cited as being associated with high damage levels are tree-killing pests familiar to readers of this blog: the brown spruce longhorn beetle, the European gypsy moth in North America, and the Asian longhorned beetle (write-ups on all three species can be read here. In my view, the high ranking of these insects reflects a (welcome!) effort by researchers to quantify tree pests’ impacts; although damages caused by agricultural pests are more easily reduced by pesticide applications.

The situation is likely to worsen in the future. According to the authors, climate change, rising human population densities, human mobility, and intensifying international trade will allow these costly insects to spread into new areas. Still, substantial savings could be achieved by increasing surveillance, containment and public awareness (my emphasis).

In an interview with Agence France Presse, one of the coauthors, Franck Courchamp said the best way to combat this growing threat — spread mainly through international commerce — is not more pesticides. Instead, “The solution is better ‘bio-security’,” he said. “This includes inspection of ship and air cargo from certain regions, legislation to ensure that high-risk imports must be treated and rapid eradication of new incursions.” (Interview is posted at http://www.bangkokpost.com/news/world/1102417/invasive-insects-cause-tens-of-billions-in-damage-study)

Source

Bradshaw, C. J. A. et al. Massive yet grossly underestimated global costs of invasive insects. Nat. Commun. 7, 12986 doi: 10.1038/ncomms12986 (2016). (Open access)

Posted by Faith Campbell

Asian Longhorned Beetle (ALB) – Newly Detected Infestation Shows Spread within Ohio

On November 18, Ohio authorities and APHIS announced the discovery of Asian longhorned beetle- infested trees in a section of Clermont County previously thought to be free of the insect. (The press release is not yet posted to the web; go here to see the most recent information).

The center of the newly discovered infestation is within the Williamsburg Township portion of the East Fork Wildlife Area, south of Clover Road. Tree inspection crews will continue to survey the area to determine the extent of the infestation. Any trees found to be infested will be removed as part of the eradication effort. Also, authorities will expand the ALB quarantine to include areas near the new infestation. When available, a map of the regulated areas will be posted at agri.ohio.gov.

This setback reminds us how difficult it is to contain or eradicate this insect.

ALB was first discovered in Tate Township in Clermont County, Ohio, in June 2011. That quarantine currently covers a 61-square miles area. According to the October 28 APHIS electronic newsletter, more than 2 million trees in the quarantine zone have been surveyed. The survey has detected 18,614 infested trees since 2011. 87,151 trees have been removed; Of these, 17,995 were infested and 69,156 were deemed at high-risk of either already being infested or likely to become infested in the immediate future.

Status of ALB in Other States

Massachusetts ALB was first detected in Worcester in 2008. The quarantine covers 110 square miles. At least 35,870 trees have been removed in the Commonwealth.

New York ALB was first detected in Queens in August 1996. APHIS and the state continue efforts to eradicate ALB from three separate infestations in Queens, Brooklyn, and Amityville. The quarantine covers a total of 137 square miles. The number of infested Trees for the entire New York program is 7,082. The number of trees removed is 23,731. Outbreaks in several sites have been declared eradicated:

Islip (Suffolk County) in 2011;
Manhattan and Staten Island in 2013.

In 2013, the Amityville area infestation was found to be larger than previously known.

The total number of trees removed in the Massachusetts, New York, and Ohio programs was 146,000. However, this is not the total for all the damage caused by the Asian longhorned beetle.

ALB outbreaks in Illinois (Chicago) and New Jersey were eradicated earlier, and their removals are not included in the total given above.

In Illinois, according to Haack et al. 2012, 1,771 trees were removed and 286,227 were treated with systemic pesticides (imidacloprid).

In New Jersey (again, according to Haack et al. 2009, 21,981 infested and high-risk trees were removed. Another 480,574 trees were treated. This total is not complete since the program had not yet succeeded in eradicating the ALB in New Jersey at the time of writing.

The total from all programs is 169,752.

The risk of new introductions remains.

During fiscal years 2010 – 2016, Customs (CBP) detected tree-killing pests in 4,984 shipments – an average of 807 shipments each year. (For the 2015 report, go here)
An analysis by Haack et al. (2014) concluded that one tenth of one percent of the wood packaging entering the U.S. after adoption of ISPM#15 still contained a tree-killing pest. Since the U.S. imports approximately 25 million shipping containers each year, and about half of these contain wood packaging, an “approach rate” of 0.1% equals 13,000 containers harboring pests that probably enter the country each year. That is 35 potential pest arrivals per day.
Customs send samples of intercepted wood packaging to an APHIS laboratory where the insect larvae are grown to adulthood and identified. The APHIS lab has received 1,068 insects from April 2012 through August 2016, taken from 786 separate interceptions of non-compliant wood packaging. Six of the insects were Asian longhorned beetles.

APHIS also detected 69 other pests in wood packaging sent from China.

The United States and Canada began requiring wood packaging from China to be treated in December 1998. (See my discussion of this regulation in Fading Forests II here. Since the Customs data begin in 2010, we can see that 11 to 16 years after the rule governing Chinese wood packaging went into effect, we are still receiving wood packaging with pests from that country.

Also, 700 pests arrived from 36 other countries, led by Mexico, Turkey, and Ukraine (see presentation here; search for “Nadel”)

What are APHIS & CBP doing about these flagrant violations of existing rules? Each violation exposes our forests to additional pest attack and our citizens to higher costs – either in local or federal taxes or personal costs to remove trees — as well as to mental anguish and health impacts.

The evidence is in. APHIS and Customs should tighten enforcement of ISPM#15 by:

Prohibiting imports in solid wood packaging (boards) from foreign suppliers which have a record of repeated violations over the 10 years ISPM#15 has been in effect. (It’s been 16 years for exporters from Hong Kong and mainland China). A reasonable number of violations should trigger this prohibition – perhaps eight over the entire period.

The U.S. should allow imports from those suppliers that are contained in other types of packaging materials, including plastic, metals, fiberboards …

Fining an importer for each new shipment found to be out of compliance with ISPM#15 if the foreign supplier of that shipment has a record of repeated violations (but fewer than the number that would trigger a ban) over the 10 years ISPM#15 has been in effect (16 years for exporters from Hong Kong & mainland China). The number of violations needed to trigger the fine might be five over the entire period – not just in one year.

Ensuring that exporting countries understand that foreign suppliers that change their names or take other steps to obscure their past import records will be prosecuted for fraud. This penalty should be severe so as to deter deliberate attempts to avoid the consequences of past actions.

References

Haack, R.A., F. Herard, J. Sun, J.J. Turgeon. 2009. Managing Invasive Populations of Asian Longhorned Beetle and Citrus Longhorned Beetle: A Worldwide Perspective. Annu. Rev. Entomol. 2010. 55:521-46.

Posted by Faith Campbell

The Latest on Phytophthoras

Phytopthora ramorum on tanoak in California; F.T. Campbell

Nine eastern states are participating in the 2016 USDA National Phytophthora ramorum Early Detection Survey of Forests. Those states are AL, FL, GA, MS, NC, PA, SC, TN, and TX. As of late August, streams in four locations were P. ramorum-positive. Three are in AL, one in MS. All had tested positive in previous years. Also, all have been associated with previously positive nurseries. (Reported in the California Oak Mortality Task Force newsletter for September.) It is reassuring that no new positive locations have been detected. However, on what substrate is the pathogen persisting? Scientists agree that the pathogen does not survive in water (although it is reliably detected by testing in water) but must survive on some plant material – perhaps roots.

P. ramorum also persists in nurseries. Seven California nurseries are participating in the APHIS federal P. ramorum program under which they are allowed to ship host plants interstate. Positive plants have been detected in two of them. One of these nurseries is undergoing the Confirmed Nursery Protocol clean-up. The other has completed the cleanup and has been allowed to resume shipping plants interstate. In both cases, the infected plants were not from the five “high-risk” genera which are the focus of monitoring for the regulatory system — Camellia, Kalmia, Pieris, Rhododendron, and Viburnum. (Reported in the California Oak Mortality Task Force newsletter for September.) I expressed concern about this too-narrow focus in a blog posted in July 2015 – http://nivemnic.us/2015/07/.

I have written about the widespread presence of various Phytophthoras in nurseries in blogs in April (for Europe http://nivemnic.us/2016/04/ ) and July (for California http://nivemnic.us/2016/07/ ). New publications add to this picture.

Junker and colleagues (see references below) report the detection of 15 Phytophthora species in two commercial woody ornamental nurseries (presumably in Europe, since the authors are Europeans). Twelve of the species are previously described but the DNA of three isolates did not match any of the known species. Detections were highest in puddles on nursery pathways; followed by plant residues;, wind-carried leaves; and water and sediment from runoff. The plant samples showed very low infection rates – a disturbing finding given the reliance until recently on inspection of plants to detect the pathogen. (Reported in the California Oak Mortality Task Force newsletter for September.)

New Phytophthora confirmed in U.S.

The United States has the first official confirmed detection of the pathogen Phytophthora quercina. It was found associated with oak trees planted on restoration sites in central coastal California. Although the California detection is the first officially confirmed detection of the pathogen in the U.S., a P. quercina ‘like’ organism has been reported to be associated with oak decline in forests in the Midwest. P. quercina is a pathogen associated with oak decline across Europe. It was rated as the species of highest concern in a USDA Plant Epidemiology and Risk Analysis Laboratory (PERAL) report. Another pathogen, P. tentaculata, was rated fifth on the same list. It was recently found in association with multiple native plant species in California’s native plant nurseries (see my July blog, linked above). See also California Oak Mortality Task Force newsletter at http://www.suddenoakdeath.org/news-and-events/current-newsletter/

Rapid Response Might Have Contained SOD – When will authorities learn this lesson?

Earlier this year, experts on modeling the epidemiology of plant disease concluded that the sudden oak death epidemic in California could have been slowed considerably if aggressive management actions – backed by “a very high level of investment” – had started in 2002. By then, there was sufficient knowledge about the disease to guide actions. Management actions should have focused on the leading edge of the epidemic (admittedly, that edge has proven difficult to detect). The study is by American and British scientists (Cunniffe, Cobb, Meentemeyer, Rizzo, and Gilligan). See reference and news report below.

The authors’ estimate documents the high costs of inaction. This is an important lesson – which has been repeated many times. If only officials from California and APHIS would take this to heart regarding several other forest pests. These include the polyphagous and Kuroshio shot hole borers and even the goldspotted oak borer (all described here).

References

https://www.sciencedaily.com/releases/2016/05/160502161111.htm?utm_source=feedburner&utm_medium=email&utm_campaign=Feed%3A+sciencedaily%2Fplants_animals%2Finvasive_species+%28Invasive+Species+News+–+ScienceDaily%29

Cunniffe, N.J., R.C. Cobb, R.K. Meentemeyer, D.M. Rizzo, and C.A. Gilligan. Modeling when, where, and how to manage a forest epidemic, motivated by SOD in Calif. PNAS, May 2016 DOI: 10.1073/pnas.1602153113

Junker, C., Goff, P., Wagner, S., and Werres, S. 2016. Occurrence of Phytophthora in commercial nursery production. Plant Health Progress. 17:64-75.

Posted by Faith Campbell

Europe moves to curtail forest pest introductions – but strongest measures are hampered by trade rules

ALB in Europe; photo by Doris Holling WSL

Maartje J. Klapwijk and several colleagues have recently taken a hard look at non-native forest pests in Europe. They conclude that current European legislation is inadequate to prevent forest/tree pest introduction, establishment and spread in the European Union. (A link to the article is provided at the end of this post.)

Some of the proactive steps that they recommend, however, will be difficult to enact. International trade rules (World Trade Organization, Agreement on the Application of Sanitary and Phytosanitary Measures – SPS Agreement) require that countries prove that the target commodity in trade presents a significant pest risk – proof that is difficult to obtain before damage has actually occurred.

(I have written extensively about this “Catch 22” – see Fading Forests II here)

Furthermore, European Union rules prevent countries from taking proactive measures to restrict potentially pest-infested plants or wood products being traded from one EU member country to another. However, member countries’ vary in their levels of concern about tree-killing pests. As a result, phytosanitary measures are quite weak in some countries. Once a pest-infested shipment enters a country with a weak phytosanitary system it can be moved freely to any other member country.

Thus, international and EU rules together create a significant risk that a pest will enter, establish, and then be spread by commerce to the rest of the Union.

The authors note that growing trade in living plants and wood products has brought a rise in non-native tree pests becoming established in Europe. The number of alien invertebrate species has increased two-fold since 1950; the number of fungal species has increased four-fold since 1900. Few studies have attempted to quantify the economic impacts of non-native tree-killing pests in Europe. But the authors say that the introduced pests will cause economic damage either directly by reducing the revenue of the country or imposing control costs; or indirectly through trade restrictions or reduced values of real estate.

Among the recent introductions are the pinewood nematode from North America; Asian and Citrus longhorned beetles and ash dieback fungus from Asia; and sudden oak death and other Phytophthora species. (I described the extent of Phytophtphora infestations in European nurseries in a blog posted on April 25.) As a partial response, EU countries have created a network of nurseries intended to serve as an early warning system against further introductions of alien tree pests. (Descriptions of these pests and where they are found are available on the website of the European and Mediterranean Plant Pest Organization (EPPO) here)

ALB introduction sites in Europe

The European Union regulates invasive species through the Environment Directorate-General (DG Environment). However, tree-killing pests and other plant health concerns are the responsibility of a different governmental body, the Directorate-General Health and Food Safety (DG SANCO).

Maartje J. Klapwijk and colleagues note the risk associated with:

crates, pallets, and other forms of wood packaging;
wood chips (Europe imports more than 4 million tons of wood pellets as fuel in order to meet its carbon emission reduction goals) ; and
especially – living plants.

They note that the international community has adopted two international related sanitary agreements : ISPM#15 (wood packaging) and ISPM#36 (living plants). The European Union requires certificates stating that imported plants are free from harmful organisms and that phytosanitary measures stipulated by the importing country have been applied. However, limited resources mean that only a small proportion of living plants, plant material, soil and wood products arriving in Europe can be inspected. “The main purpose of the inspections is to verify whether shipments comply with regulations, rather than to stop potentially harmful organisms …” (my emphasis). Reflecting the differences in levels of concern among EU member states noted above, there are large differences in inspection intensity among the EU member states.

The pertinent European legislation is Directive 2000/29/EC. It relies on a ‘‘black-list’’ of plants and plant products that are banned from import and specifies procedures to apply when any of these banned products is found in the EU. According to Klapwijk and colleagues, these quarantine lists provide insufficient protection because harmful organisms that enter the EU often are unknown prior to establishment.

Aware of the current system’s inadequacies, the EC has proposed a new regulation which would simplify and harmonize plant passports, allow for stricter measures against pests, and address emerging risks from certain living plant imports from some non-EU countries. Instead of listing harmful plant pests, the proposed regulation “sets out the conceptual nature of quarantine pests” and empowers the Commission to adopt measures to control certain pests.

Klapwijk and colleagues praise these actions as a significant step forward. However, they note that the new rules still don’t provide for precautionary assessments of high-risk commodities. Nor do they restrict import of the highest-risk commodities, such as imports of large plants or plants in soil. (my emphasis)

The authors note that other countries take a more pro-active, precautionary stance. Australia and New Zealand require that all imported plant products be assessed and proved safe before import. The U.S. restricts the size of imported plants and does not allow imported plants to be in soil. (The U.S. has proposed a new approach that relies increasingly on integrated measures or systems approaches rather than port-of-entry inspection. However, this proposal has been pending for more than three years. (APHIS explains its proposal here)

The question is, do trade rules allow Europe to apply the same restrictions as other countries? As Klapwijk and colleagues note, the EU cannot adopt more rigorous phytosanitary measures without providing scientific evidence for this necessity. Preparing a risk assessment to make this case will involve considerable work. As part of this process, Europe should announce that it wishes to raise its “level of protection” and that more stringent phytosanitary measures are needed to achieve that new goal.

Meanwhile, the EU can enhance its active detection efforts and “rapid response” capabilities. The new EC directive will require countries in which a new pest is detected to eradicate or contain the pest. However, the response continues to depend on investments and actions by individual Member States – which have often been insufficient.

Klapwijk and colleagues endorse the suggestion by Hulme et al. (2009) that the European Commission establish a single agency to respond to introductions of any kind of invasive species (not just tree pests) – modeled on the European Centre for Disease Prevention and Control.

Finally, Klapwijk and colleagues note the importance of engaging the public. Citizens’ participation can enhance early detection and strengthen public support for management strategies.

CONCLUSIONS

We Americans are very lucky that the U.S. Department of Agriculture had fairly stringent rules governing plant imports before the World Trade Organization and SPS Agreement were negotiated in the 1990s. We don’t have the burden of proving that imports of large plants (small trees!) in soil is too risky. (This not to say that U.S. regulations should not be tightened further for the most high-risk imports. See Fading Forests III here). Europeans should be able to build their case for more restrictive trade rules on existing risk assessments and practices utilized by the U.S., Australia, New Zealand, and others; on the numerous studies published in recent years that describe recent introductions to Europe and the pathways by which they entered; and by the number of those introductions alone. (To see what has been introduced, visit the website of the European and Mediterranean Plant Pest Organization (EPPO) here)

One important step in improving U.S. rules would be to finalize the proposal – put forward in 2013 – to depend more on integrated measures or systems approaches rather than inspection at the port of entry. Join with me in urging the Secretary of Agriculture to finalize this proposal before he leaves office in January. Contact me via the “contact us” button on the webpage to learn how you can help.

The United Kingdom has voted to leave the European Union. This means that the U.K. has the opportunity – and burden – of developing its own phytosanitary regulations. The U.K. has some of the leading forest pathologists and entomologists. The risk is obvious to all – especially Phytophthora ramorum in larch plantations and ash dieback disease in many areas of the country. I hope that the British will seize this opportunity to adopt really effective phytosanitary regulations that can serve as a model for the rest of Europe – and possibly even the U.S.

Sources

Maartje J. Klapwijk, Anna J. M. Hopkins, Louise Eriksson, Maria Pettersson, Martin Schroeder,A°ke Lindelo¨w, Jonas Ro¨nnberg, E. Carina H. Keskitalo, Marc Kenis. 2016. Reducing the risk of invasive forest pests and pathogens: Combining legislation, targeted management and public awareness. Ambio 2016, 45(Suppl. 2):S223–S234 DOI 10.1007/s13280-015-0748-3

Hulme, P.E. 2009. Trade, transport and trouble: Managing invasive species pathways in an era of globalization. Journal of Applied Ecology 46:10-18

Posted by Faith Campbell