wood packaging – Center for Invasive Species Prevention

Wood packaging: serious data gaps … but clear opportunities to act

discarded pallets next to developed area in **Glacier National Park** (!); photo by F.T. Campbell

Since July 2015 I have posted nearly 50 blogs about non-native insects introduced via movement of solid wood packaging material (SWPM). Why? Because SWPM is one of two most important pathways by numbers introduced & by impact of the species introduced. (The other pathway is P4P.) To read those earlier blogs, scroll below “archives” to “categories”, choose “wood packaging”.

Examples of insects introduced via the wood packaging pathway include Asian longhorned beetle, emerald ash borer, redbay ambrosia beetle, Mediterranean oak borer, and possibly, three species of invasive shot hole borers.

dead redbay trees in **Everglades National Park**; killed by laurel wilt vectored by redbay ambrosia beetle

As I have reported in the earlier blogs and in my “Fading Forests” reports (links at the end of this blog), in 2002, the parties to the International Plant Protection Convention (IPPC) adopted an international “standard” to guide countries’ programs intended to reduce the presence of damaging insects in the wood packaging: International Standard for Phytosanitary Measures (ISPM) #15). The U.S. and Canada adopted the standard through a phase-in process culminating in 2006. [For a discussion of the phase-in periods and process, read either of the studies by Haack et al. cited at the end of this blog.] In other words, the U.S. and Canada have implemented ISPM#15 for almost 20 years. China specifically has been subject to requirements that it treat its SWPM even longer – since December, 1998, i.e., more than 25 years.

Unfortunately, ISPM#15 is not intended to prevent pest introductions. As stated in Greenwood et al 2023, “Prior to 2009, the goal of compliance with ISPM 15 was to render the risk of wood-borne pests “practically eliminated,” in 2009 the standard was amended to “significantly reduced”.

Despite almost universal adoption of the standard by countries engaged in international trade, insects have continued to be present in wood packaging. A very high proportion of these infested shipments — 87% – 95% — of the SWPM found by U.S. officials bears the ISPM#15 stamp – that is, is apparently compliant. (See my blogs by clicking on the “Category” “wood packaging” listed below the “Archives”.) The same proportion was found in a narrower study in Europe (Eyre et al. 2018). All the post-2006 examples of infested wood analyzed by Haack et al. (2022) (see below) carry the stamp. I conclude that the ISPM#15 mark has failed in its purpose: to reliably indicate that SWPM accompanying imports has been treated so as to minimize the likelihood that an insect pest will be present.

Dr. Robert Haack, retired USFS entomologist, has twice tried to estimate the “approach rate” of insects in SWPM entering the United States (both studies are cited at the end of this blog). A study published in 2014 that relied on data from 2009 found that U.S. implementation of ISPM#15 was associated with a reduction in the SWPM infestation rate reported of 36–52%. The authors estimated the infestation rate to be 0.1% (1/10^th of 1%, or 1 consignment out of a thousand). (See Haack et al. 2014; citation at the end of this blog.)

In their second study, published in 2022, Haack and colleagues found a 61% decrease in rates of borer detection in wood packaging when comparing numbers of wood borer detections in 2003 – before the U.S. implemented ISPM#15 – to those in 2020. Specifically, detections dropped from 0.34% in 2003 to 0.21% in 2020. This decrease occurred despite the volume of U.S. imports rising 68% between 2003 and 2020. (My blogs document a further increase in import volumes over the years since 2020.) In addition, the number of countries from which the SWPM originated more than doubled from 2003–2004 to 2010–2020. This expansion exposes North America to a wider range of insect species that might be introduced, as well as a wider range of individual countries’ effectiveness in enforcing the standard’s requirements (Haack et al. 2022).

These decreases are encouraging. However, Haack et al. (2022) note some caveats:

The reduction in pest presence was greatest during the initial implementation of the program the first phase, 2005-2006 (61%); in subsequent periods pest approach rate inched back up. In the 2010-2020 period, the pest detection rate was only 36% below the pre-ISPM#15 level. Detection rates have been relatively constant since 2005. Does this stasis mean that exporters learned that they could ignore or circumvent the requirements without suffering significant penalties? Or is some of this rise related to increased trade volumes, increasing variety of country of origin for trade, or other global trade patterns unrecognized in the data? (However, see the next bullet point.)
Certain types of commercial goods and exporting countries have consistently fallen short. Specifically, the rate of wood packaging from China that is infested remained relatively steady over the 17 years since 2003. The proportion of consignments with infested wood packaging coming from China was more than five times the proportion of all inspected shipments for this period. In other words, China has had a consistent record of poor compliance with phytosanitary regulations since they were imposed in December 1998. Why is USDA not taking action to correct this problem? (As I note below, DHS CBP has ramped up enforcement efforts.) Some other countries, e.g., Italy and Mexico, have reduced the rate at which wood packaging accompanying their consignments is infested. In fact, Mexico’s improved performance largely explains the overall infestation rate estimate of 0.22% during the period 2010-2010. Mexico’s successes affect the overall statistics in a way that makes other countries’ failure to reduce the presence of pests in wood packaging they ship to the United States far less obvious.

Haack et al. (2022) discuss ten possible explanations for their finding that pest approach rates – as determined by their study — have not decreased more. See the article or my blog about the study.

Although USDA APHIS has not taken steps to strengthen its enforcement, U.S. Customs and Border Protection [an agency in the Department of Homeland Security] has done so twice — see here and here. CBP staff have expressed disappointment that these actions reduced the numbers of shipments in violation of ISPM#15 by only 33% between Fiscal Year 2017 and FY2022. True, more than 60% of these violations consisted of a missing or fraudulent ISPM#15 stamp. However, 194 consignments still harbored live pests prohibited under the standard.

APHIS did agree in 2021 to enable the study by Robert Haack and colleagues, via an interoffice data sharing agreement between USDA APHIS and the Forest Service- this resulted in Haack et al. 2022.

APHIS and CBP also collaborated with an industry initiative to train inspectors that insure other aspects of foreign purchases. The ideas was that CBP or APHIS and their Canadian counterparts would inform importers about which foreign treatment facilities have a record of poor compliance or suspected fraud. The importers could then avoid purchasing SWPM from them. I have heard nothing about this initiative for three years, so I fear it has collapsed.

We lack data on which to base a rigorous analysis

While the two studies by Robert Haack and colleagues are the best available, and they relied on the best data available, the fact is that those available data do not provide a full picture of the risk of pest introduction associated with wood packaging. As pointed out by Leigh Greenwood of The Nature Conservancy in her presentation to 2025 USDA Invasive Species Research Forum, available data have been collected for different purposes than to answer this question. Leigh’s powerpoint is posted here.

Leigh has identified the following data gaps:

In their studies, Haack and colleagues rely on data from the Agriculture Quarantine Inspection Monitoring (AQIM) system. This dataset is based on random sampling of very distinct segments of incoming trade. It is therefore a better measure of insect approach rates than reports of interceptions by either APHIS or CBP.

However, AQIM includes data from only those very distinct segments of trade: perishable goods, SWPM associated with maritime containerized imports, Italian tiles, and “other” goods, AQIM does not contain a segment of trade that includes wood packaging associated with maritime breakbulk or roll-on, roll-off (RORO) cargo. These exclusions have prevented scientists and enforcement officials from determining, inter alia, how great a risk of pest introduction is associated with various types of wood packaging, especially dunnage, as the randomized sample does not include entire pathways for the entrance of dunnage.

Greenwood states that she has not found another country that operates a similar analysis of randomly collected data at ports of entry.

2) USDA does not collect data on consignment size, piece-specific infestation density, nor consignment-wide infestation density. As Haack et al. (2022) point out, reporting detections by consignment doesn’t reveal the number of insects present. If implementation of ISPM#15 resulted in fewer live insects being present in an “infested” consignment, this would reduce the establishment risk because there is lower propagule pressure. However, we cannot know whether this is true.

3) Neither USDA nor CBP reports the inspection effort. Nor do they conduct a “leakage survey” to see how often target pests are missed. This means, inter alia, that we cannot estimate inspectors’ efficiency in detecting infested wood packaging. If their proficiency has improved as a result of improvements in training, inspection techniques, or technology, the apparent impact of ISPM#15 would be under-reported in recent years.

4) USDA does not require port inspectors to report the type of SWPM in which the pest was detected. Leigh participated in an effort that included industry representatives, DHS CBP and USDA APHIS to define the types of wood packaging in legal terminology so that they could be incorporated in the drop-down menu on inspectors’ reporting system. This was first successfully included in the legal glossary within USDA APHIS system of record, ACIR Glossary. Last fall the team was working to integrate the requirement for using these definitions into the inspection data collection system used by DHS CBP, which would then make this data available in Agricultural Risk Management, ARM (see Abstract here for adequate primer on ARM). However, it is unclear now whether the new administration will do so. One potential barrier is that asking the port of entry inspection staff to record these data will add to the time and training required for reporting inspection results.

In summary, Leigh reports that current data systems do not support

estimating probabilities of pest infestation of via volume or type of SWPM (e.g. pallet vs dunnage)
measuring the risk of arrival associated with a specific hazard (in this case, a hazard being a live pest or pathogen associated with SWPM)
extrapolating or supporting findings for some types of wood packaging to other types of wood packaging

Scientists from Canada, Mexico, and the United States have formed a working group under the auspices of the North American Plant Protection Organization (NAPPO). The group is trying to determine whether various types of wood packaging are more likely to harbor pests. This study is currently hampered by the many data gaps, including those Leigh outlined above. The best data available, cited by Haack et al. (2022), found that in maritime containerized shipping, crates were more likely to harbor pests than pallets- however, other forms of SWPM (dunnage, bracing, etc.) had such low sample size that no analysis of those is possible. One of the main objectives of the NAPPO study is to evaluate if dunnage poses the same or higher risk, so this is a major impediment.

Two issues need to be resolved.

One is scientific: why are insects continuing to be detected in wood packaging marked as having been treated? What is the relative importance of insects surviving the treatment versus treatment facilities applying the treatments incorrectly or inadequately?

The second issue is legal and political: what proportion of the detections is due to treatment facilities committing outright fraud – claiming to treat the wood, stamping it with an IPPC stamp, while not actually performing any treatments at all?

Knowing which measures will most effectively solve these quandaries / reduce pest presence in wood packaging depends on knowing what the relative importance of these factors are in causing the problem. The lack of basic data on which to base any analysis certainly hampers efforts to improve protection.

Leigh calls for researchers to recognize these data needs and work to fill them.

•Understand, account for, and communicate data realities

•Work collectively to increase useable data quality

•Use additional research to validate, or to demonstrate disparities

Why Wait for the Science?

In the meantime, however, I assert that more vigorous enforcement efforts by responsible agencies should help reduce the occurrence of fraud. I have suggested the following actions:

U.S. and Canada refuse to accept wood packaging from foreign suppliers that have a record of repeated violations – whatever the apparent cause of the non-compliance. Institute severe penalties to deter foreign suppliers from taking devious steps to escape being associated with their violation record.
APHIS and CBP and their Canadian counterparts follow through on the industry-initiated program described above and here aimed at helping importers avoid using wood packaging from unreliable suppliers in the exporting country.
Encourage a rapid switch to materials that won’t transport wood-borers. Plastic is one such material. While no one wants to encourage production of more plastic, the Earth is drowning under discarded plastic. Some firms are recycling plastic waste into pallets.

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.

For a detailed discussion of the policies and practices that have allowed these pests to enter and spread – and that do not promote effective restoration strategies – review the Fading Forests report at https://treeimprovement.tennessee.edu/

www.fadingforests.org

Coming to an Ecosystem Near You??

*Xylotrechus chinensis*; EPPO photograph

Europe has been invaded by two insect species that North Americans should be watching out for. First, a Cerambycid, the wasp-mimicking tiger longicorn beetle, Xylotrechus chinensis. And second,the Buprestid cypress jewel beetle, Lamprodila festiva. We should also ensure that none of the other 500+ beetles introduced to Europe poses a threat to our trees. These are summarized in a 2024 paper by Bunescu et al.

Tiger Longicorn Beetle

This beetle is native to eastern Asia. It feeds on and kills mulberry trees (Moraceae: Morus spp.). It might also attack apple and pear trees and grapevines – Asian sources report these as hosts. The status of grapevines has been questioned by a Spanish experiment, in which artificial inoculations failed. I have seen no further information about the vulnerability of apple (Malus spp.) and pear (Pyrus spp.) (Saarto i Monteyu, Costa Ribeu, and Savin 2021)

In Europe, the pest threatens mulberry trees which are commonly planted for shade and ornamentation, especially in southern France, Spain and Greece (Saarto i Monteyu, Costa Ribeu, and Savin 2021). For example, there are more than 20,000 mulberry trees in Athens (EFSA 2021). The trees’ abundance contributes to spread of any associated pests, the level of damage caused by falling branches, and the expense of tree removal. Economic damages are those typically associated with wood-borer invasions of urban areas. That is, the cost of tree removals, loss of shade and amenity values, and increased risk of injury from falling branches.

We Americans should be concerned, too. Wild red mulberry (Morus rubra) occupies much of the eastern United States, from southern New England west to southeastern Minnesota, then south along the eastern edge of the Great Plains to central Texas, and east to southern Florida. It is also found in Bermuda. It grows primarily in flood plains and low moist hillsides. . Presumably it would also be attacked by Xylotrechus chinensis, although I don’t know whether anyone has tested this. As a native tree, red mulberry plays a role in natural ecosystems, including wildlife food supplies. Thus, America would see even more significant losses if Xylotrechus chinensis were to establish.

*Morus rubra* in Fairfax County, Virginia; photo by Fmartin via Wikipedia

Red mulberry is already declining in parts of its central range, possibly due to a bacterial disease. The effects and extent of this disease have not been investigated thoroughly.

Apples and pears are important crops across North America; the farm-gate value is estimated at $3.2 billon.

Introductions of the beetle to Spain, France, and Greece might have resulted from inadequately-treated wood packaging or other wood products. Detections of the species in wood imports were reported in Germany in 2007 and 2017 (Saarto i Monteyu, Costa Ribeu, and Savin 2021). The U.S. has also intercepted X. chinensis at least once, at the port of Philadelphia, in 2011 (EFSA 2021).

These detections have raised questions to which no-one yet has answers. First, can X. chinensis develop in cut logs? The European Food Safety Agency concluded that it can (EFSA 2021). Second, one detection involved a shipment of wooden items made from birch (Betula spp.) and willow (Salix spp). It is not yet clear whether these taxa are also hosts (EFSA 2021). (The wood species were not specified in the case of the other interceptions.) I have blogged often about how “leaky” the wood packaging pathway has been; to see these blogs, scroll below the “archives” section of the webpage, then click on the category “wood packaging”.

European scientists believe X. chinensis might also be transported in shipments of plants for planting. However, the beetle prefers to oviposit on large trees. This pathway is less viable for the United States since USDA APHIS allows imports of mulberries (Morus) and pears (Pyrus) only from Canada. Apple trees (Malus spp.), however, may be imported from France – which hosts an introduced population of X. chinensis – and other European countries.

Detection of any invasion by X. chinensis will pose the usual difficulties associated with woodborers. In some European cities, hundreds or even a thousand trees were infested before the outbreak was detected (EFSA 2021).

I am concerned that the Europeans appear to have been slow to respond to the threat from Xylotrechus chinensis. After several outbreaks were discovered in Greece, France, and Spain in 2017 and 2018, the European and Mediterranean Plant Protection Organization (EPPO) added X. chinensis to its Alert List. This action requires member states (which are not limited to European Union members) to report new outbreaks and inform about efforts to either stop or eradicate them (Saarto i Monteyu, Costa Ribeu, and Savin 2021).

Shortly afterwards the European Union Commission requested the European Food Safety Agency (EFSA) to conduct a risk assessment. This analysis was completed in 2021. (It contains lots of photos of the insect and its damage.) The analysis concluded that Xylotrechus chinensis could probably infest most areas in the Union and cause significant damage. The species meets the criteria for designation as a quarantine pest in the Union. However, as of December 2024, this action had not been taken. As a result, control measures for this species are not mandatory.

Introductions continue; an outbreak in Lombardy, Italy, was found in June 2023 (Sarto i Monteys, Savin, Torras i Tutusaus & Bedós i Balsach 2024). European regulations – following IPPC standards – also are linked to named pests and known outbreak locations. Such restrictions almost guarantee that the pest will continue to spread from not-yet-detected outbreaks. (Decades ago, after the emerald ash borer invasion, Michigan’s State Plant Regulatory Official, Ken Rasher, noted that, to be effective, “slow the spread” efforts must apply to areas beyond the known limits of the pest’s range.) The EFSA risk assessment did suggest delimitation of buffer zones around known European outbreaks. I don’t know whether such zones have been set up.

The risk assessment also recommended [true?] improving detection of this insect by developing male pheromones as lures. These have not been acted on. Guidance on best timing for treatment [trunk injections of systemic insecticides] also appears to have been taken up by Greece but not by Spain (Sarto i Monteys, Savin, Torras i Tutusaus & Bedós i Balsach 2024).

These authors include more information about the Xylotrechus chinensis life cycle and trajectory of the invasion,. They note that climate change appears to be altering the insect’s phenology. Especially, the adult flight period is beginning earlier in the spring.

*Lamprodila festiva*; Udo Schmidt via flickr

Cypress jewel beetle

This second pest of concern is a buprestid that attacks trees in the Cupressaceae. Infested trees generally die within a few years.

In its native Mediterranean range, the beetle feeds on native Juniperus, Cupressus and Tetraclinis. In invaded urban landscapes of Europe it attacks primarily introduced Cupressaceae , particularly Thuja, Chamaecyparis, Platycladus, Callitris, and some hybrids (Cupressocyparis). It has also been recorded as damaging Sequoia sempervirens (Brunescu, et al., 2024). (Genera in bold are native to North America.)

Thuja occidentalis; photo by H. Zell via Wikimedia

White cedar, Thuja occidentalis is the focus of Brunescu, et al.’s article. It is native to eastern Canada and much of the north-central and northeastern United States. The European and Mediterranean Plant Protection Organization (EPPO) has identified eight species in the Lamprodila genus as important pests, (Brunescu et al. 2024) so the danger might be more widespread. The invasion of Europe is probably the result of adult flight or other short-range transport. The article does not suggest pathways that the species might exploit to cross oceans.

SOURCES

Bunescu, H., T. Florian, D. Dragan, A. Mara, I-B. Hulujan, X-D. Rau. 2024 The Cypress Jewel Beetle Lamprodila Festiva Linné, 1767 (Coleoptera: Buprestidae), an Invasive Major Pest of Thuja Occidentalis Linné in Romania Hop and Medicinal Plants, 2024 XXXII, No. 1-2, 2024.

Saarto i Monteyu V., A. Costa Ribeu. I. Savin. 2021a. The invasive longhorn beetle Xylotrechus chinensis, pest of mulberries, in Euro: Study on its local spread & efficacy of abamectin control Plos One January 29, 2021. https://doi.org/10.1371/journal.pone.0245527

Sarto i Monteys, V., I. Savin, G. Torras i Tutusaus & M. Bedós i Balsach. 2024b. New evidence on the spread in Catalonia of the invasive longhorn beetle, Xylotrechus chinensis, & the efficacy of abamectin control. Scientific Reports | (2024) 14:26754 | https://doi.org/10.1038/s41598-024-78265-x www.nature.com/scientificreports/

Posted by Faith Campbell

www.fadingforests.org

Urban forests – resource under many threats

ash tree in Michigan killed by emerald ash borer; photo courtesy of (then) Mayor John Hieftje

The Forest Service is promoting its efforts to protect urban forests [see the Northeast Region’s “Roots in Research” in mid-December 2024]. The rationale is that urban forests provide substantial environmental and economic benefits that deserve more attention. These include air purification, temperature regulation and energy savings, water absorption, and improved public health. At the same time, urban forests face multiple and overlapping threats – including the one of greatest concern to us, introduction of tree-killing non-native insects and pathogens.

The article on which the Roots in Research “Science Brief” is based was actually published in 2022 in the Journal of Forestry. In it, David Nowak, Eric Greenfield, and Alexis Ellis evaluated historical and current threats to urban forests across the contiguous states and projected them 50 years into the future. Threats included urban expansion, climate change, insect infestation, and extreme weather events. Their goal was to help urban forest managers and policymakers prioritize resources and planning efforts.

I believe stakeholders should view these projects as underestimates because the sources Nowak et al. relied on for both future climatic conditions and non-native pest impacts are incomplete or outdated. I am not criticizing the choice of sources – they are the standard ones. But events have raised questions about their accuracy.

Nowak, Greenfield, and Ellis expected that urban tree cover will decline significantly by 2060. The principle cause is urban expansion — development of previously wooded areas. Development has traditionally been the leading cause of urban forest loss.

Newer threats have become obvious in recent decades – i.e., pest and disease attacks and extreme weather events.

coast live oak infected by GSOB; Heisey County Park, San Diego County photo by F.T. Campbell

The most troubling example of the sources’ weaknesses is the Alien Forest Pest Explorer (AFPE), on which the authors rely for their list of non-native insects and pathogens present in the United States. However, the compilers of this database decided not to include pests that are native to some parts of North America but are behaving as bioinvaders in other regions. The premier example is the goldspotted oak borer (GSOB), Agrilus auroguttatus. This insect kills three species of oaks native to southern California – coast live oak (Quercus agrifolia), California black oak (Q. kelloggii), and canyon live oak (Q. chrysolepis). Twelve years ago scientists estimated that GSOB had killed at least 100,000 trees in San Diego County; it has since been detected in widespread infestations in four other counties in southern California.

Not including GSOB (or Mediterranean oak borer; see below) skews the findings because of the importance of the oaks in California’s urban forests. Their genus is the second most-abundant native genus in the state’s urban forest, making up 6.5% of the trees. Because many of these trees are large, they contribute significantly to the ecosystem benefits provided by urban forests. Out of the 152,594 coast live oaks in 287 cities statewide, at least 30,000 of them meet GSOB’s preferred size limit (DBH greater than 18 – 20 inches [~45 cm]) (Love et al. 2022). The highest presence of oaks in urban forests in the South is in Santa Barbara – which has not yet been invaded by GSOB. However, built-up sections of Los Angeles – which are heavily invaded already — have between 250,000 and 300,000 coast live oak trees.

The Alien Forest Pest Explorer also does not include pests of palms. Palms are the first and second most the abundant species in urban areas of both the Southern California Coast and Southwest Desert regions (Love et al. 2022). Of course, palms contribute little to the ecosystem benefit associated with urban forests, but they are iconic symbols of the region. California’s palms are under attack by the South American palm weevil. https://cisr.ucr.edu/invasive-species/south-american-palm-weevil

More difficult to understand is the AFPC’s failure to include the Mediterranean oak borer, (MOB) (Xyleborus monographus). MOB has been introduced from Europe, so it fits the AFPE’s criteria for inclusion. MOB is killing valley (Quercus lobata) and blue oaks (Q. douglasii) in Lake, Napa, Sacramento, and Sonoma counties in California and Oregon oak (Q. garryana) in Troutdale, Salem, and other towns in Oregon.

*Quercus lobata*, killed by Mediterranean oak beetle

As to the data sources relied on for projections of future climatic factors, several measurements of the changing climate already exceed projections in the models. They expect intensified threats from changes in air temperature, precipitation, aridity, wildfire risk, flooding, and sea level rise. By 2060, temperatures in urban areas are expected to increase by 1.2 – 3.5° C. Nowak and colleagues expected this warming to exacerbate threats from heat stress, flooding, increased salinity, drought, and wildfire. Less certain but possible are more intense storms and pest outbreaks. As I noted above, perhaps even these projections understate the threats.

For example, in discussing flooding the authors relied on measurements of the historic 100-year flood plain. I understand that experts now say this standard is inadequate, given existing records and projected further increases in precipitation (especially high-intensity storms). Urban areas in 98% of the 2,424 counties Nowak et al. analyzed contain flood-prone areas.

Nowak et al. do mention two additional elements exacerbating the flood risk: the spread of impervious surfaces and location of many cities next to bays or wide rivers. In these latter cases, risks might include salt intrusion linked to higher water levels, even in the absence of flooding. The National Oceanographic and Atmospheric Administration’s “intermediate high” scenario projects sea level will rise 61 cm by 2060.

Nowak, Greenfield, and Ellis said the greatest overall threat is in the eastern states, especially New England other than Vermont and Maine; the mid-Atlantic; South Carolina; and Ohio. They say this arises from the combination of high levels of urbanization and accumulation of several threats. The specific threats include projected precipitation changes, storms (hurricanes in the southeast; ice storms in the Appalachians); sea level rise; and the abundance of non-native pests. I think that reliance on data from the past results in understating the hurricane risk in the Northeast (especially the Hudson and Connecticut river basins) and in North Carolina.

Nowak, Greenfield, and Ellis reminded us that a healthy urban forest canopy can help mitigate some of the threats associated with climate change. This applies particularly to local air temperatures. Reducing urban heat islands not only addresses a direct threat; it can also moderate such other threats as pest infestations, wildfire, aridity, and storm damage, especially runoff. They advocate science-based tree management programs including preserving existing trees and planting species that can thrive in the expected new local and regional environment, e.g., withstand droughts, flooding, saltwater exposure, or extreme temperatures.

I think their recommendation on pest threats is lame: they suggested “monitoring and managing local pest threats.” Non-native pests demand additional actions at all levels of authority — local, state, and federal. (See the “Fading Forests” reports linked to at the end of this blog, and earlier blogs under the category “invasive species policy”.) I have already noted troubling exclusion of some pests already present in urban areas of the continental United States. I understand that it is impossible to predict which additional pests might be introduced in the next 50 years. But I would have appreciated a sentence stating the near certainty that more pests will be introduced and cause damage to urban forests in the next 50 years.

Given the recent fires in the Los Angeles region, I believe we need new analyses of the risk of wildfire in cities and the positive and negative interactions with the urban forest.

SOURCES

Threats to Urban Forests in the United States Roots in Research Issue 45 | December 2024 https://research.fs.usda.gov/nrs/ products/rooted-research/threats-urban-forests-united-states?utm_source=MarketingCloud&utm_medium=email accessed 24-12/31

Nowak, D.J., E.J. Greenfield, and A. Ellis. 2022. Assessing Urban Forest Threats across the conterminous United States. Journal of Forestry, 2022, Vol. 120, No. 6

Posted by Faith Campbell

www.fadingforests.org

Import volumes continue to rise (although exact numbers elusive)

obvious risk of pest introduction! photo by F.T. Campbell

Because of the many damaging insects introduced in wood packaging, I often blog about numbers of shipping containers entering the country. [On the “nivemnic.us” website, scroll down below “archives” to “categories”, then click on “wood packaging” to see my previous blogs discussing this issue.]

The Department of Homeland Security’s Bureau of Customs and Border Protection (CBP) reports processing 36.6 million shipping containers holding imports in Fiscal Year 2023 – which ended in September 2023. These presumably included about 13 – 16 million containers arriving via ship from Asia, Europe, and other overseas trading partners. The remaining millions probably entering from Mexico and Canada via land transport. Together, Mexico and Canada provided 30% of U.S. imports in 2022.

It is difficult to pin down the actual number of containers entering the country. In contrast to the figure provided by CBP, Laura Robb of the Journal of Commerce reports that 25.6 million TEUs carrying imports entered the country in 2024. This figure apparently includes containers carried by all forms of transport. CBP counts containers by actual numbers, and about 90% of waterborne containers are actually 40 feet long, not the 20 feet measured by “TEU” (U.S. DoT). Halving the JOC number results in a total of about 13 million – well below that reported by CBP.

Overall volumes of imports carried by ship continue to rise. The monetary value of goods imported by the U.S. in maritime trade grew 15% from 2021 to 2022 (U.S. DoT). Robb reported that trade experts believe imports rose another 15% between 2023 and 2024. This rise is driven by retailers trying to protect themselves from a possible longshoremen’s strike (which might occur beginning 15 January), Trump’s threatened tariffs (he might act as early as 20 January); and the annual slowdown of production in Asia during Tet (which begins on 29 January). If import volumes meet expectations and continue through April, the series will outdo the previous (pandemic-era) record of 19 straight months when imports exceeded 2 million TEUs. What happens later in 2025 depends in part on whether the anticipated strike happens and/or actual levels of any new tariffs.

One concern about imports from Mexico and Canada is that some proportion of these goods actually originated in Asia or Europe, but were shipped through Mexican or Canadian ports. I have not found a source to clarify how many shipments fit this pattern. USDA APHIS used to blame forest pests introduced to the Great Lakes region on goods transported from the principal Canadian Atlantic port, St. John, Nova Scotia.

A useful publication for identifying where the pest-introduction risk is highest are the annual reports issued by U.S. Department of Transportation’s Bureau of Transportation Statistics. In calendar year 2022, U.S. maritime ports handled just under 43% of U.S. international trade (measured by value). There are two caveats: the data include both imports and exports; and the most recent data are from 2021.

Two-thirds of America’s maritime cargo (imports and exports) is shipped in traditional containers. This includes most consumer goods. The top 25 container ports handled a total of 45.6 million TEU (U.S. DoT). Map 4-3 in the report shows these ports and the proportions that are imports and exports.

The highest-ranking Container Ports in 2021 are those we expect. The ports of Los Angeles and Long Beach were numbers one and two. Together they received 10.7 million TEU. The third highest number of containers entered through the Port of New York & New Jersey. Nearly 5 million TEU entered there. The Port of Savannah ranked fourth. Savannah and nearby Charleston (ranked seventh) handled 4.2 million incoming TEUs in 2021.

Ranked above Charleston were the Port of Virginia and Houston. Each processed approximately 1.8 million containers filled with imports. Three West coast ports follow: Oakland, California and Tacoma and Seattle. Just over 1 million TEUs entered Oakland. The two Washington ports received a little over 1.5 million. Florida has four ports ranked in the “top 25”. In total, they processed 1.2 million TEU; most entered through PortMiami and Port Everglades. Baltimore, Philadelphia, Mobile, New Orleans, Wilmington, North Carolina and Wilmington, Delaware, South Jersey Port Corporation, and Boston all handled less than 500 imported containers in 2021. Domestic shipments from other U.S. states dominated containers processed through the ports of San Juan, Honolulu, and Alaska.

gantry crane in operation at the Port of Savannah; photo by F.T. Campbell

The top ports must have appropriate facilities needed to load / unload container vessels efficiently– that is, adequate numbers of gantry cranes, especially super post-Panamax cranes, which have the greatest capacity. The top 25 container ports of 2021 operated a total of 539 ship-to-shore gantry cranes in 2023, of which 322 (60%) are post-Panamax cranes. Ports are adding cranes – there were 29 more in 2023 than in 2021. The Port of Virginia appears to be striving for significant increases in tonnage; it has 28 Panamax cranes, more than Charleston and almost as many as Savannah (U.S. DoT).

Another important port component is efficient facilities to load containers onto rail cars or trucks for transfer to land-based warehouses and retailers. Ports have more than one terminal; for example, the Port of Long Beach has six, New York/New Jersey has five. Nationwide, 70% of container terminals have on-dock facilities to transfer containers directly onto rail cars. All but three of the 33 terminals located at Long Beach. Los Angeles, New York, Savannah, Charleston, Houston 2/2, Seattle, and Tacoma have on-dock transfer equipment.

The U.S. DoT reports also inform us about the top 25 ports that handle other categories of cargo: overall tonnage, dry and liquid bulk cargo, break bulk cargo, and roll-on-roll-off cargo. Visit the report to view these data.

SOURCES

Robb, L. 2024. U.S. import “surge” to persist into spring amid continued frontloading: retailers. Journal of Commerce Daily Newswire December 10, 2024

U.S. Customs and Border Protection FY 2023 CBP TRADE SHEET https://www.cbp.gov/document/annual-report/fy-2023-cbp-trade-fact-sheet

U.S. Department of Transportation, Bureau of Transportation Statistics, Annual Report 2024 Port Performance Freight Statistics January 2024 https://www.bts.gov/explore-topics-and-geography/modes/maritime-and-inland-waterways/2024-port-performance-freight

Posted by Faith Campbell

www.fadingforests.org

Two Non-Native Insects Threaten Forest, Salmonid, and Waterway Conservation in Pacific Northwest

Oregon ash dominate wetlands of Ankeny NWR; photo by Wyatt Williams, Oregon Department of Forestry

One of these insects is the emerald ash borer (EAB). We easterners have “been there & done that”. However, programs aimed at conserving wetlands and riparian areas of the Western states – and the associated species — are at least as vulnerable to loss of ash. Worse, other tree taxa, specifically oaks, and the open woodlands they inhabit — are also under threat. The ecological tragedies continue to affect ever more forests.

|Emerald Ash Borer in Oregon and British Columbia

The emerald ash borer (EAB; Agrilus planipennis) was detected in Oregon in June 2022. Officials had been expecting an introduction and had begun preparations. Unsurprisingly, the infestation is more widespread than known at first: detections in two new locations, fairly close to the original in Forest Grove, mean the infested area now occupies three neighboring counties — Washington, Yamhill, and Marion counties.

Oregon officials are trying to slow spread of EAB by removing infested trees. Surveys in Washington County had identified 190 infested ash trees; 80 were removed in April 2024. They treated healthy ash trees in Washington County with injections of the systemic insecticide emamectin benzoate. The effort was already a daunting task: the survey had disclosed 6,500 ash trees in the vicinity. The city of Portland – only 25 miles away – has 94,000 ash trees (Profita 2024).

In May, 2024 EAB was detected in the city of Vancouver in British Columbia. This detection in the sixth Canadian province adds to the threat to the ecosystems of the region. The Canadian Food Inspection Agency (CFIA) now regulates the movement of all ash material such as logs, branches, and woodchips, and all species of firewood, from the affected sites.

The CFIA is also conducting surveillance activities to determine where EAB might be present, and is collaborating with the City of Vancouver, the Vancouver Board of Parks and Recreation, the Province of British Columbia, and other stakeholders to respond to the detections and slow the spread of this pest.

Importance of Oregon ash (Fraxinus latifolia)

The Oregon ash is the only ash species native to the Pacific Northwest. Its range stretches from southern British Columbia to so California, where it has hybridized with velvet ash (F. velutina). It is highly susceptible to EAB attack; there is a high probability that Oregon ash could be rendered functionally extinct (Maze, Bond and Mattsson 2024). This vulnerability prompted the International Union for Conservation of Nature (IUCN) to classify Oregon ash as “near threatened” as long ago as 2017 (Melton et al. 2024).

Oregon ash typically grows in moist, bottomland habitats. There it is a late-successional climax species. In Oregon’s Willamette Valley and Washington’s Puget Trough, the tree improves streams’ water quality by providing shade, bank stabilization, and filtration of pollutants and excess nutrients. Maintaining these ecological services is particularly important because these streams are crucial to salmonids (salmon and trout) and other native aquatic species (Maze, Bond and Mattsson 2024).

So it is not surprising that one component of Oregonians’ pre-detection preparations was an analysis of the likely impact of widespread ash mortality on populations of salmon, trout, and other aquatic species. I summarize the key findings of Maze, Bond and Mattsson here.

According to this study, salmonids and other cold-water aquatic species suffer population declines and health effects when stream water temperatures are too warm. A critical factor in maintaining stream temperatures is shade – usually created by trees. In the Pacific Northwest many streams’ temperatures already exceed levels needed to protect sensitive aquatic species. A key driver of increased stream temperatures – at least in the Willamette Basin – is clearing of forests to allow agriculture.

Decreasing streams’ temperatures is not only a good thing to do; it is legally required by the Endangered Species Act because several salmon and steelhead trout species are listed. In one response, the Oregon Department of Environmental Quality recommends restoration and protection of riparian vegetation as the primary methods for increasing stream shading and mitigating increased stream temperatures in the lower Willamette Basin.

The forests shading many low-elevation forested wetlands and tributaries of the Willamette and lower Columbia rivers are often composed exclusively of Oregon ash. Loss of these trees’ shade will affect not just the immediate streams but also increase the temperature of mainstem waterways downstream.

Oregon ash – EAB detection site; photo by Wyatt Williams, Oregon Department of Forestry

Replacements for Oregon Ash?

The magnitude of the ecological impacts of ash mortality in the many forested wetlands in the Willamette Valley will largely be determined by what plant associations establish after the ash die. Oregon ash is uniquely able to tolerate soils inundated for extended periods. No native tree species can fill the void when the ash die. Oregon white oak (Quercus garryana), black cottonwood (Populus trichocarpa), and the alders (Alnus rubra and A. rhombifolia), are shade intolerant and unlikely to persist in later seral stages in some settings.

If non-native species fill the gaps, they will provide inferior levels of ecosystem services – I would think particularly regarding wildlife habitat and invertebrate forage. Maze, Bond and Mattsson expect loss of ash to trigger significant physical and chemical changes. These will directly impact water quality and alter native plant and animal communities’ composition and successional trajectories.

The authors cite expectations of scientists studying loss of black ash (F. nigra) from upper Midwestern wetlands. There, research indicates loss of ash from these systems is likely to result in higher water tables and a conversion from forested to graminoid- or shrub-dominated systems. Significant changes follow: to food webs, to habitat structure, and, potentially, to nitrogen cycling.

Maze, Bond and Mattsson expect similar impacts in Willamette Valley wetlands and floodplains, especially those with the longest inundation periods and highest water tables. That is, there will probably be a broad disruption of successional dynamics and, at many sites, a conversion to open, shrub-dominated systems or to wetlands invaded by exotic reed canary grass (Phalaris arundinacea), with occasional sedge-dominated (Carex obnupta) wetlands. They think this change is especially likely under canopies composed of Oregon white oak (see below). The authors admit some uncertainty regarding the trajectories of succession because 90 years of water-control projects has almost eliminated the possibility of high-intensity floods.

Oregon Ash and Salmonids

Maze, Bond and Mattsson point out that all salmonids that spawn in the Willamette basin and the nearly 250,000 square mile extent of the Columbia basin upstream of Portland pass through the two wooded waterways in the Portland area that they studied. Applying a model to simulate disappearance of ash from these forests, the authors found that the reduced shade would raise the “solar load” on one waterway, which is wide and slow-moving, by 1.8%. On the second, much narrower, creek (mean channel width of 7 m), solar load was increased by of 23.7%.

Maze, Bond and Mattsson argue that even small changes can be important. Both waterbodies already regularly exceed Oregon’s target water temperature throughout the summer. Any increase in solar loading and water temperatures will have implications for the fish – and for entities seeking to comply with Endangered Species Act requirements. These include federal, state, and local governments, as well as private persons.

The Willamette and lower Columbia Rivers, and their tributaries, traverse a range of elevations. Ash trees comprise a larger proportion of the trees in the low elevation riparian and wetland forests. Consequently, Maze, Bond and Mattsson expect that EAB-induced loss of Oregon ash will have significant impacts on these rivers’ water quality and aquatic habitats. The higher water temperatures will affect aquatic organisms at multiple trophic levels.

They conclude that the EAB invasion West of the Cascade Mountain range constitutes an example of the worst-case forest pest scenario: the loss of a dominant and largely functionally irreplaceable tree species that provides critical habitat for both ESA-listed and other species, along with degradation of ecosystem services that protect water quality.

Breeding Oregon Ash … Challenges to be Overcome

According to Melton et al. (2024), Oregon ash does not begin to reproduce until it is 30 years old. Such an extended reproductive cycle could complicate breeding efforts unless scientists are able to accelerate flowering or use grafting techniques to speed up reproduction – as suggested by Richard Sniezko, USFS expert on tree breeding.

Melton et al. (2024) note that the IUCN has recently highlighted the importance of maintaining a species’ genetic variation in order to maintain its evolutionary potential. Consequently, they examined genetic variation in Oregon ash in order to identify the species’ ability to adjust to both the EAB threat and climate change. The authors sequenced the genomes of 1,083 individual ash trees from 61 populations. These spanned the species’ range from Vancouver Island to southern California. The genetic analysis detected four genetic clusters:

British Columbia;
Washington to central Oregon – including the Columbia River and its principal tributaries;
Southwest Oregon and Northwest California — the Klamath-Siskiyou ecoregion; and
all other California populations.

Connectivity between populations (that is, the potential corridors of movement for pollen and seeds and hence, genetic flow) was greatest in the riparian areas of the Columbia River and its tributaries in the center to the species’ range. Despite this evidence of connectivity, nucleotide diversity and effective population size were low across all populations. This suggests that the patchy distribution of Oregon ash populations might reduce its long-term evolutionary potential. As average temperatures rise, the regional populations will become more distinct genetically. The species’ ability to adjust to future climate projections is most constrained in populations on Vancouver Island and in smaller river valleys at the eastern and western edges of the range. Populations in southern California might be “pre-adapted” to warmer temperatures.

The resulting lower effective population size might exacerbate risks associated with EAB. The authors warned that although seeds from more than 350 maternal parent trees have been preserved since 2019, these collections do not cover the full genomic variation across Oregon ash’s range. Some genomic variation that represents adaptive variation critical to the species’ long-term evolution might be missing. They advocate using the genetic data from their study to identify regions where additional collections of germplasm are needed for both progeny trials and for long-term conservation.

Oregon white oak with symptoms of Mediterranean oak borer infestation; photo by Christine Buhl, Oregon Department of Forestry

Oregon White Oak (Quercus garryana) and the Mediterranean Oak Borer

The U.S. Department of Interior has been working with regional partners for 10 years to protect oak and prairie habitat for five ESA-listed species, two candidate species, and numerous other plant and animal species of concern. In August 2025 the Department announced creation of the Willamette Valley Conservation Area. It becomes part of the Willamette Valley National Wildlife Refuge Complex. These units are managed predominantly to maintain winter habitat for dusky geese (a separate population of Canada geese). Other units in the Complex are William L. Finley National Wildlife Refuge, Ankeny National Wildlife Refuge, and Baskett Slough National Wildlife Refuge.

These goals too face threats from non-native forest pests. First, the forested swamps of Ankeny NWR are composed nearly 100% of ash.

Second, Oregon white oak now confronts its own non-native pest – the Mediterranean oak borer (Xyleborus monographus). This Eurasian ambrosia beetle has been introduced to the northern end of the Willamette Valley (near Troutville, Oregon). It is likely that infestations are more widespread. Authorities are surveying areas near Salem. A separate introduction has become established in California, north of San Francisco Bay plus in Sacramento County in the Central Valley. Oregon white oak is vulnerable to at least one of the fungi vectored by this borer – Raffaelea montety. https://www.dontmovefirewood.org/pest_pathogen/mediterranean-oak-borer/

SOURCES

Maze, D., J. Bond and M. Mattsson. 2024. Modelling impacts to water quality in salmonid-bearing waterways following the introduction of emerald ash borer in the Pacific Northwest, USA. Biol Invasions (2024) 26:2691–2705 https://doi.org/10.1007/s10530-024-03340-3

Melton, A.E., T.M. Faske, R.A. Sniezko, T. Thibault, W. Williams, T. Parchman, and J.A. Hamilton. 2024. Genomics-driven monitoring of Fraxinus latifolia (Oregon Ash) for conservation and emerald ash borer resistance breeding. https://link.springer.com/article/10.1007/s10530-024-03340-3

Profita, C. April 26, 2024. State crews remove trees in Washington County to slow spread of emerald ash borer. Oregon Public Broadcasting. https://www.opb.org/article/2024/04/26/oregon-invasive-beetle-emerald-ash-borer-infestation-tree-removal/#:~:text=It%20was%20first%20detected%20in%20Oregon%20in%20Forest%20Grove%20in%20June%202022.&text=This%20week%2C%20crews%20removed%20dozens,ash%20trees%20from%20the%20area.

Posted by Faith Campbell

www.fadingforests.org

What I learned at the NPB meeting

The National Plant Board’s members are the lead plant health officials of the states and territories. Many federal officials also attend – from APHIS and DHS Bureau of Customs and Border Protection. Representatives of other North American phytosanitary entities participate – i.e., Canada, Mexico, and the North American Plant Protection Organization (NAPPO). Some stakeholder groups participate, especially the nursery industry. I have attended these meetings for over a decade because they provide an overview of pest issues and programs plus an unparalleled opportunity to network. The Nature Conservancy’s Leigh Greenwood also attends. We are the only representatives of the species conservation community to attend – others are missing great opportunities.

Here, I’ve listed 10 items that are among the most important the group discussed.

1) The funding situation for APHIS is worse than I realized

APHIS Administrator Mike Watson and Deputy Administrator (for plants) Mark Davidson both spoke about the need to cut programs to stay within the limits set by congressional appropriations. Funding for APHIS, as a whole, was cut only 1% for the current year (Fiscal Year 2024), cost-of-living salary increases mean less money for programs. (I believe Dr. Watson said $41 million less for FY24). If FY25 funding is the same, Congressionally mandated additional payraises will mean an another $20 million decrease in program funding.

Dr. Davidson said that the plant programs (Plant Protection and Quarantine) had been cut by 5% in FY24. However, Congress did not finalize the funding levels until about half-way through the fiscal year – so staying within the limits required even more severe cuts to programs in the remainder of FY24. To stay within these limits, APHIS cut several programs, among them a $3.6 million cut from the “tree and wood pest” program. This meant loss of funds to manage the polyphagous and Kuroshio shot hole borers, smaller cuts for programs managing Asian longhorned beetle and emerald ash borer, and perhaps the Asian flighted spongy moth. They anticipate additional cuts in these programs in FY25. The one bright light is the Section 7721 Plant Pest & Disease Management & Disaster Prevention Program. It provides steady funding for a range of plant health programs. The House version of the still-pending Farm Bill calls for increasing funding for this program by $15 million each year.

Nearly 100% ash trees in Oregon wetland — exposed to spreading EAB. Photo by Wyatt Williams, Oregon Department of Forestry

Remember this when I ask you to lobby for appropriations! If we don’t advocate for funding the programs dealing with “our” pests, they will shrink.

Watkins and Davidson also worry that whoever is the next secretary of USDA might not support the agency when it seeks to withdraw funds to cover emergencies from the Commodity Credit Corporation – as Secretary Vilsack has.

APHIS and the DHS Customs and Border Protection (CBP) both praised a recent regulatory action that increases user fees for importers having goods cleared at ports. Kevin Harriger, CPB official in charge of agriculture programs, said the new funds would allow CBP to hire 700 new agricultural inspectors (currently there are 2,800 agricultural officials). That sounds great, but … when trade and passenger volumes crashed early in the COVID pandemic, things looked dicey for a while. Plus – as I have argued repeatedly – real protection against pest introductions will come from stronger policies, not ramped-up inspections.

Pathologist Bruce Moltzan reported on the USFS Forest Health Protection program. He pointed out that the USFS has a very limited toolbox. In this fiscal year, the program has about $48 million, after salaries, to support its activities. Projects targetting insects receive 70% of the funding; those targetting pathogens 15%.

2) Invasive hornets

Washington State has not found any new nests of the Northern (formerly Asian) giant hornet (Vespa mandarinia). Miraculous!

However, Georgia detected another species, the yellow-legged hornet (Vespa velutina), near Savannah in August 2023. The Georgia Department of Agriculture, APHIS, and the University of Georgia are working to find nests – which are located at the top of tall pine trees in residential areas. Five nests were found in 2023; another four so far in 2024. Georgia hopes to place traps 100 miles out from each detection site. Like the northern hornet, V. velutina preys on honey bees. It was probably transported by ship or with its cargo.

A third species, V. tropica, has been introduced on Guam.

3) Better Federal-State Cooperation — Sometimes

APHIS and the state phytosanitary officials have set up structures – e.g., Strategic Alliance/Strategic Initiative, or SASI – to work together more closely. CBP joins the coordinating meetings. One program described at the meeting is the effort to contain spread of the box tree moth (Cydalima perspectalis). This effort came out of discussions at last year’s Plant Board meeting, with follow-up gatherings of APHIS, the states, and the nursery industry. The moth is known to be present in New York, Massachusetts, Michigan, Ohio, and now Delaware – plus several Canadian provinces.

A second project concerns how much data to share about state detections of pests – which are recorded in the National Plant diagnostic Network database. These data have accrued over 20 years … and are sought by both other states and academic researchers. States are often reluctant to allow public review of detection data because they fear it will cause other states or private parties to avoid buying plants or other goods from the infested area. While the project team has not yet decided how to deal with these conflicts, they said they were more inclined to share “nonconsequential data” – meaning data on a pest everyone already knows is present, not a pest under regulation or a new detection. In other words, “consequential” seems to pertain to industry profits, not damage to agricultural or natural resources.

EAB-killed ash along Mattawoman Creek, Maryland. Photo by Leslie A. Brice

4) Update: 20 years of tackling the emerald ash borer

Craig Kellogg, APHIS’ chief plant health representative in Michigan, reviewed 20 years of dealing with the emerald ash borer (EAB). He is optimistic about the impact of the biocontrol agents that have now been released in 32 states and four provinces. The larval parasitoids are dispersing and EAB densities are coming down. He conceded that over-story and mature ash are still dying, but says ash in long-infested areas are regenerating well. Scientists agree (see Wilson et al. 2024; full citation at end of the blog). Woodpeckers are still the most effective biocontrol agent of EAB for over-story ash, especially in locations where introduced parasitoids are not established. So far, the growing numbers of biocontrol agents are still parasitizing too few EAB larvae to prevent decline of over-story ash trees.

5) Flighted Spongy Moths

APHIS reported on recent detections of flighted spongy moth from Asia on ships coming to U.S. ports. The program covers four closely related species of Lymantria. All have much broader host ranges than Lymantria dispar, plus the females are capable of sustained flight, so they spread more rapidly.

The principal strategy to prevent their introduction is to require ships that call at ports along the Pacific coast in Russia, China, Japan, and North and South Korea to ensure that the ships’ superstructures and cargo are clean. Before arriving at U.S. ports, the ship’s captain must inform CBP where it has called over the last 24 months. Then, CBP conducts an inspection. If CBP inspectors find a small number of egg masses, they remove the eggs and spray pesticide. If the inspectors detect a large number of egg masses, the ship is ordered to leave port, clean itself, and undergo re-inspection before it can return.

Four countries in the Americas – the U.S., Canada, Chile, and Argentina – and also New Zealand have very similar programs.

Detections follow natural changes in population levels in the exporting regions. APHIS’ program leader, Ingrid Asmundsson, reported on an unfortunate coincidence in 2014. A huge moth population outbreak occurred simultaneously with very low fuel prices in Russia. The latter attracted many ships to call there. An even bigger population surge occurred in 2019. Asmundsson expects another high-moth period this year.

flighted spongy moths infesting a ship superstructure

APHIS is working on putting this program on a regulatory foundation; this would allow the agency to be more specific in its requirements and to impose penalties (other than expulsions from ports). I’ll let you know when the proposed rule is published for comment.

6) Regional Reports: Old Pests, New Pests

Representatives of the regional plant boards informed us of their “new pest” or other concerns.

Gary Fish, president of the Eastern Plant Board, mentioned

the need for additional research on management of beech leaf disease
concern about impact of box tree moth and vascular streak dieback on the nursery industry (the latter is a threat to dogwood and redbud)
spread of elm zig-zag sawfly in Vermont and Connecticut
awareness that laurel wilt is moving into Virginia and maybe farther north.

elm zig-zag sawfly; photo by Gyorgy Csoka *via* Bugwood

There was a more general discussion of beech leaf disease. What can be done, given that the disease is so widespread that no one is regulating movement of beech. Gary Fish advised outreach and efforts to reach agreement on management approaches. Chris Benemann, of Oregon, suggested informing other states so that they can decide whether to take regulatory action. A representative of CBP urged engaging stakeholders by asking for their help.

Chris Benemann, President of the Western Plant Board, expressed concern about APHIS’ reduced funding for spongy moth detection and control efforts. She also worries about the recently detected population of Phytophthora austrocedrii in an Oregon nursery. The western states are also focused on several longstanding pest problems – grasshoppers, Japanese beetle; and a new beetle from Australia that is attacking almonds, pistachios, and walnuts.

tree infested by hemlock woolly adelgid; photo by F.T. Campbell

Megan Abraham of Indiana reported that members of the Central Plant Board are concerned about

funding decrease for APHIS and USFS efforts to slow the spread of spongy moth and manage Asian longhorned beetle and emerald ash borer;
Invaders associated with Christmas decorations, e.g., hemlock woolly adelgid, elongate hemlock scale, and balsam woolly adelgid
spotted lanternfly finding new ways to travel;
invasion by beech leaf disease and possibly by sudden oak death;
elm zig-zag sawfly entering the region;
boxwood blight, potato pests, honeybee pests, and invasive plants – e.g., Hydrilla.

She noted that nursery stock is increasingly coming from more distant – and cheaper – producers, raising the risk of new pests being introduced.

Finally, Abraham expressed concern about decreased funding at the same time as the need is growing – and asked with whom states should collaborate in order to reverse this trend.

Kenny Naylor of Oklahoma, Vice President of the Southern Plant Board, concurred that funding levels are a major concern. He mentioned specifically the spongy moth Slow the Spread program and eradication of the Asian longhorned beetle outbreak in South Carolina. Another concern is the Georgia hornet outbreak.

7) Phasing Out Post-Entry Quarantine

APHIS and the NPB have agreed to phase out the post-entry quarantine (PEQ) program. A program review revealed several problems, some of which astound me. When examining plants in quarantine the scientists still relying on visual inspection! And they are looking for pests identified 45 years ago (1980)! While I think PEQ programs can be valuable in preventing introduction of disease agents, as implemented in recent decades it does not. Twenty years ago, citrus longhorned beetles escaped from a “quarantine” area in a commercial nursery in Washington state. These Cerambycids are more than an inch long!

citrus longhorned beetle; photo by Art Wagner, USDA *via* Bugwood

Part of this phase-out is to transfer plant species harboring pests of concern to the Not Authorized for Importation Pending Pest Risk Assessment (NAPPRA). While the APHIS speaker said that NAPPRA allows the agency to act quickly when it detects evidence of pest risk, I have found lengthy delays. The third round of proposals was published in December 2019! The fourth round of species proposed for NAPPRA listing should be published soon; a fifth round is now in draft inside the agency.

8) Christmas Greens – Spreading Pests

Officials from Oregon, Maine, and Illinois described their concerns about pests being spread by shipments of various forest or plant products, especially Christmas greens. Mentioned were spongy moths, link hemlock woolly adelgid, link elongate hemlock scale, balsam woolly adelgid, link and box wood moth. Part of the challenge is that the vectoring items are often sold by unregulated outlets – multiple stores, Christmas tree lots – and through on-line or catalog outlets. There are also extreme demands on the regulatory enforcement staff during the brief holiday sales season. Several states are unsure whether they have authority over decorative products – although others pointed out that they are regulating the pest, regardless of the object for sale or type of store.

9) Pests in Firewood

Leigh Greenwood of The Nature Conservancy noted that the state agencies that issue firewood regulations – often the plant protection organization (state department of agriculture) — do a good job alerting the public about the risks and rules. However, the public looks first to state parks agencies for information about camping – and those agencies have less robust educational efforts. It is important to put the message where the public can find it when they don’t know it exists – before they include firewood from home in their camping gear.

10) Projects of the North American Plant Protection Organization

The North American Plant Protection Organization (NAPPO) is working on several projects of interest to those of us concerned about tree-killing pests. One project is evaluating risks associated with wood products, especially how well one international regulation, ISPM#15 is working for dunnage. Another projects is testing the efficacy of the heat treatment specified by ISPM#15 (50^o C for 30 minutes). A third project — almost completed – is evaluating fumigants that can be alternatives to methyl bromide.

In conclusion, each annual meeting of the National Plant Board is packed with new information, updates on current pests, and comments on by the state agencies who suggest new approached to APHIS and hold the agency to account. It is well worth attending. Information about upcoming meetings of both the national and four regional plant boards is posted on the NPB website, https://www.nationalplantboard.org/

Signatories to the APHIS-NPB strategic alliance

SOURCE

Wilson, C.J., T.R. Petrice, T.M. Poland, and D.G. McCullough. 2024. Tree species richness and ash density have variable effects on emerald ash borer biological control by woodpeckers & parasitoid wasps in post-invasion white ash stands. Environmental Entomology.

Posted by Faith Campbell

www.fadingforests.org

APHIS Annual Report Describes Helpful Programs … Since Cut Back Because of Funding Shortfalls

Flighted spongy moths infesting a ship’s superstructure

USDA’s Animal and Plant Health Inspection Service (APHIS) has issued its annual report for Fiscal Year 2023. The report is part of an enhanced outreach effort that I believe is an effort to persuade the Congress to provide additional funds. However, as I describe below, at this summer’s annual meeting of the National Plant Board, link APHIS’ leadership stated that funding shortfalls are forcing them to curtail many programs. These include ones important to those of us concerned about threats to North American trees. I applaud this action and hope it succeeds!

The report contains some good news but I consider the overall approach depressing. Tree-killing pests continue to receive little attention. The report also emphasizes APHIS’ efforts to facilitate export of agricultural products – an understandable stance given American politics.

The opening summarizes the agency’s activities includes:

Examples of programs targetting pests abroad, before they can reach the U.S. All are fresh fruits and vegetables;
APHIS or staff at U.S. borders:
- Approved (cleared) 27,235 shipmentscontaining over 1.87 billion plant units (e.g., a single plant or cutting, or vial of tissue culture plantlets) and 670,811 kilograms of seeds. They intercepted 2,176 quarantine pests. (APHIS carry out these inspections at Plant Inspection Stations – separate from the port environment where DHS Customs and Border Protection (CBP) staff inspects other cargo.)

Identified approximately 92,000 pestsfound during CBP inspections of cargo, mail, and express carrier shipments and took quick action to prevent those of concern from entering the U.S.
Facilitated entry of regulated agricultural cargo by monitoring more than 62,000 treatments of various kinds, that is, fumigations, cold or heat treatments, and irradiation.
Examples of APHIS’ efforts to slow pests’ spread within the country cited plant pest surveys — with coordinated responses — for approximately 45 pests. Also APHIS described funding to help citrus growers combat citrus greening.
The report has separate subreports on the following programs: risk analysis, pest detection, “specialty crop” pests, and tree and wood pests. The last two contain information specific to our interests.

Tree and Wood Pests

This program protects forests, private working lands, and natural resources. It targets specific pests: the Asian longhorned beetle, emerald ash borer, spongy moth, and most recently the invasive shot hole borers. The report notes that numerous native, widespread hardwood tree species are vulnerable to these pests. APHIS asserts an economic justification for the program: conserving forests enhances rural communities’ economic vitality, supports forest-related industries, and maintains the ecosystem services provided by urban trees.

Unfortunately, at this summer’s annual meeting of the National Plant Board APHIS leadership said funding shortfalls forced them to pull back on all these programs.

Programs as Described in the Report

Asian Longhorned Beetle

ALB eradication aims to protect the 30% of U.S. trees that are ALB hosts. These trees support multi-billion-dollar maple syrup, timber, tree nursery, trade, and tourism industries. After reviewing the history of ALB detections, starting in Brooklyn in August 1996, the report describes APHIS’ eradication strategy as comprising surveys, regulatory inspections and quarantine restrictions, removal of infested and high-risk trees, and chemical treatment applications. In FY 2023, the program surveyed more than 763,000 trees across the four regulated areas: New York, Massachusetts, Ohio, and South Carolina. Each program is summarized.

Good news at two locations. On Long Island: only 11 new infested trees were found after a survey of 43,480 trees. In Worcester County, Massachusetts, no new infested trees were found after surveying nearly 360,000 trees. However, in Tate Township, Ohio, surveys detected 163 new infested trees. And in

South Carolina, the program is at an earlier stage — surveying a portion of the quarantine area. The program surveyed nearly 140,000 trees and removed 1,700 in FY 2023.

At the National Plant Board Meeting, Deputy Administrator Mark Davidson explained that the FY2024 appropriation cut $3.6 million from the “tree and wood pests” account. This required the agency to reduce funding for the ALB eradication program.

Emerald Ash Borer

The report summarizes the spread of EAB since its first detection in 2002 in Michigan to 37 states and the District of Columbia (APHIS does not mention EAB’s presence in five Canadian provinces.)

Saying that EAB has spread beyond what a regulatory program can control, the report notes that APHIS ended the regulatory program in FY 2021. In FY 2023 the agency continued the transition to a program relying primarily on biocontrol. In FY2023, APHIS provided parasitoids to 155 release sites – three in Canada, the rest in 122 counties in 25 states. APHIS and cooperators continue to assess their impacts on EAB populations and tree health at release sites and nearby areas. Field evaluations indicate the EAB parasitoid wasps and other EAB natural enemies (woodpeckers) are protecting regenerating sapling ash from EAB.

Spongy Moths

Spongy moths (the species formerly called European gypsy moths) are established in all or parts of 20 eastern and midwestern states, plus the District of Columbia. APHIS and state cooperators regulate activities in the quarantine area to prevent the moths’ human-assisted spread to non-quarantine (non-infested) areas – primarily West coast states. To address the moths’ natural spread, APHIS PPQ monitors the 1,200-mile-long border of the quarantine area and adds newly infested areas to the regulated area. The USDA Forest Service – APHIS – Slow-the-Spread Foundation program has greatly reduced the moth’s rate of spread and has eradicated isolated populations.

Another component of the program aims to prevent introduction of members of the flighted spongy moth complex link from Asia. The Asian species have broader host ranges and the females can fly, so they could spread faster. A multi-nation cooperative program is designed to prevent the moths’ hitchhike on vessels coming from Asia. link APHIS supports this program through negotiations and support of CBP’s offshore vessel inspection, certification, and cleaning requirements. Canada participates in the same program.

In FY 2023, APHIS and state cooperators continued efforts to delimit possibly introductions in Washington State (no additional moths detected); and California and Oregon (initial detections in FY 2020).

California sycamore infested by polyphagous shot hole borer; photo by Beatriz Nobua-Behrmann UC Cooperative Extension

Shot Hole Borers

The report notes that various non-native shot hole borers have been detected in several states. Their hosts include trees in forests and urban landscapes, tea plantations, and avocado orchards. The program’s focus was apparently on the polyphagous and Kuroshio shot hole borers devastating riparian habitats in southern California and urban areas in other parts of California. At California’s request, APHIS and the USDA Forest Service helped establish a working group, led by USFS, with the goal of strategically addressing both shot hole borers in California. In FY 2023, APHIS’ helped with foreign explorations for possible biocontrol agents, as well as host specificity testing.

APHIS leadership told the National Plant Board in July 2024 that it had dropped this entire program due to funding shortfalls.

Specialty Crop Pests

While much of this report concerns pests of agricultural crops (e.g., grapes, citrus, potatoes), it also summarized efforts re: Phytophthora ramorum (sudden oak death) and spotted lanternfly. APHIS says its efforts protected nursery stock production worth approximately $1.3 billion as of 2019, and tree fruit production worth approximately $1.7 billion in 2021.

map showing areas of the Eastern United States at risk to *P. ramorum* – developed by Gilligan of Cambridge University

Phytophthora ramorum

The report states that APHIS seeks to limit P. ramorum’s spread from affected nurseries. The agency does this via regulatory strategies. During FY 2023, 16 nurseries were governed by more stringent rules under the federal program which are imposed on nurseries that have been determined in past years to harbor P. ramorum-infected plants.

In addition, Oregon officials continued surveys of an area outside its quarantine zone because of a detection the previous year. APHIS will adjust the federal quarantine depending on the state’s findings.

The APHIS report does not discuss several pertinent events that occurred in FY2023. [For more details, read the California Oak Mortality Task Force newsletters for 2023 – posted here.

First, APHIS does not mention or discuss the implications of detection of two new strains of P. ramorum — EU1 & NA2 — in west coast forests. The presence of EU1 in a new California county (Del Norte) was confirmed in Feb 2023.

Second, the report said that Oregon is trying to determine the extent of the P. ramorum infection detected outside the state’s quarantine zone. However, it does not mention that this outbreak involves the new NA2 lineage – and that NA2 was known to be present in nurseries in the region since 2005.

The report also does not clarify that three nurseries to added to the more stringent program were so treated because SOD-infected plants were found on their premises.

Nor does the report note that at least two new naturally-infected hosts of P. ramorum were identified: Western sword fern (Polystichum munitum) and Arbutus x ‘Marina’.Koch’s postulates need to be completed on the latter so it has not yet been added to APHIS’ official host list.

Spotted Lanternfly

Spotted Lanternfly (SLF) was found in 16 states in FY 2023. APHIS’ program enjoyed funding provided through Specialty Crop Pests and from the Plant Protection Act’s Section 7721 link ($6 million from the latter).

The report notes that APHIS still does not have enough data to determine SLF’s impacts on agriculture. Thus far, vineyards have been the most adversely affected agricultural segment, mostly due to SLF acting as a stressor to vines. Also, the sticky, sugary “honeydew” produced by SLF attracts other insects and promotes sooty mold growth. These can ruin the fruit and further damage the plant.

SLF populations are strongly linked to major transportation pathways, such as railroads and interstate highways. APHIS targets treatments and, in some areas, removes SLF’s preferred host plant (tree of heaven [Ailanthus]), from transportation hubs. The aim is to reduce the risk of SLF’ spread to new areas and to eradicate isolated infestations. In FY 2023, APHIS and cooperators treated 4,637 properties covering 6,455 acres in affected areas. However, during the National Plant Board meeting both state and APHIS officials complained to me that managers of these transportation hubs raise many barriers to their access, sharply limiting the program’s chance of success.

*Ailanthus altissima* – drive of spotted lanternfly invasion

The program was expanded after National Environmental Policy Act-mandated environmental review. This allowed APHIS to conduct treatments in four additional states—Indiana, Massachusetts, Michigan, and Rhode Island. In addition, program cooperators identified three potential biological control organisms, one that targets the tree of heaven and two that target SLF. APHIS will continue to evaluate them and develop methods to rear them in the laboratory.

Finally, in fiscal year 2023, APHIS joined the National Association of State Departments of Agriculture and the National Plant Board to develop a national strategic plan outlining the future direction of the SLF program. With the strategic plan, PPQ aims to harmonize the approach across states to slow SLF’s spread, develop consistent outreach messaging for a nationwide audience, and more effectively use existing state and Federal resources. Continued spread of SLF despite the huge effort, rising costs of the program, and new scientific findings spurred reconsideration of the strategy.

To summarize, I hope that APHIS’ annual report will – in the future – help members of Congress and their staff understand the agency’s programs’ purpose and past successes. This increased understanding might make it easier to advocate for more funding. I am troubled, however, by the agency’s glossing over significant problems.

Posted by Faith Campbell

www.fadingforests.org

Read both: a short call to action (41 pp) based on a long report (952 pp!) Then Act!!!

U.S. Department of Agriculture headquarters; lets lobby these people! photo by Wikimedia

Twenty-three scientists based around the world published a Letter to the Editor titled “Overwhelming evidence galvanizes a global consensus on the need for action against Invasive Alien Species” It appears in the most recent edition of Biological Invasions (2024) 26:621–626.

The authors’ purpose is to draw attention to the release of a new assessment by the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services’ (IPBES).

The report was issued in September 2023. It is described as the most comprehensive global synthesis of the current knowledge on the bioinvasion process and the impacts of invasive alien species (952 pages!). Its preparation took nearly a decade. Most important, it represents the first consensus among governments and scientists worldwide on the magnitude and extent of the threats that bioinvasions pose to nature, people, and the economy.

The proposed solutions are astoundingly broad and ambitious: transformation of how governments and societies perform. I don’t disagree! However, we need interim steps – “bites of the elephant.” In my view, the report falls short on providing these.

Our challenge: join others in bringing this analysis to decision-makers’ attention. Can we pull out information that will help persuade U.S. decision-makers – governmental and non-governmental – that the threat is both urgent and solvable? How do we more effectively advocate for the aggressive, science-based action that we all know is needed?

(I hope that the fact that the report was prepared under the auspices of the Convention on Biodiversity, to which the U.S. is not a party, does not intensify the challenge for us.)

Why we need to restructure the behavior of governments and societies

Bioinvasions are facilitated by policies, decision-making structures, institutions, and technologies that are almost always focused on achieving other goals. Species transport and introduction are driven by policies aimed at promoting economic growth – especially trade. Later stages of invasions, i.e., establishment and some spread, are accelerated by certain uses of land and sea plus climate change. For example, activities that fragment habitats or cause widespread habitat disturbance provide ready places for bioinvasions. Rarely are those who gain by such policies held accountable for the harms they produce via bioinvasions.

To address these unintended consequences, the IPBES report calls for “integrated governance.” Its authors want coordination of all policies and agencies that touch on the indirect drivers, e.g., conservation; trade; economic development; transport; and human, animal, and plant health. Policy instruments need to reinforce – rather than conflict with — strategic invasive species management across sectors and scales. This involves international agreements, national regulations, all governmental sectors, as well as industry, the scientific community, and ordinary people – including local communities and Indigenous Peoples.

The report also calls for establishment of open and inter-operable information systems. This improved access to information is critical for setting priorities; evaluating and improving regulations’ effectiveness; and reducing costs by avoiding duplication of efforts.

Critically important information that is often unspoken:

Indirect causes underlying the usual list of human activities that directly promote bioinvasions are the rapid rise of human population and even more rapid rise in consumption and global trade.
Biosecurity measures at international borders have not kept pace with the growing volume, diversity, and geographic origins of goods in trade.

Continuation of current patterns is expected to result in one-third more invasive species globally by 2050. However, this is an underestimate because today’s harms reflect the consequences of past actions – often from decades ago. Drivers of invasions are expected to grow in both volume and impact.
We can prevent and control invasive alien species – but that success depends on the availability of adequate, sustained resources, plus capacity building; scientific cooperation and transfer of technology; appropriate biosecurity legislation and enforcement; and engaging the full range of stakeholders. These require political will.
A major impact of bioinvasion is increased biotic homogenization (loss of biological communities’ uniqueness). This concerns us because we are losing the biotic heterogeneity that provides insurance for the maintenance of ecosystem functioning in the face of ongoing global change.
The IPBES study asserts that successfully addressing bioinvasions can also strengthen the effectiveness of policies designed to respond to other drivers, especially programs addressing conservation of biological diversity, ensuring food security, sustaining economic growth, and slowing climate change. All these challenges interact. The authors affirm that evidence-based policy planning can reflect the interconnectedness of the drivers so that efforts to solve one problem do not exacerbate the magnitude of others and might even have multiple benefits.

More Key Findings

Overall, 9% (3,500) of an estimated 37,000 alien species established in novel environments are invasive (those for which scientists have evidence of negative impacts). Proportions of invasives is high among many taxonomic groups: 22% of all 1,852 alien invertebrates; 14% of all 461 alien vertebrates; 11% of all 141 alien microbes; and 6% of all 1,061 alien plants. (The discussion of probable undercounts relates to aquatic systems and certain geographic regions. However, I believe these data are all undermined by gaps in studies.)
Invasive alien species – solely or in combination with other drivers – have contributed to 60% of recorded global extinctions. Invasive species are the only driver in 16% of global animal and plant extinctions. Some invasive species have broader impacts, affecting not just individual species but also communities or whole ecosystems. Sometimes these create complexoutcomes that push the system across a threshold beyond which ecosystem restoration is not possible. (No tree pests are listed among the examples.)

dead whitebark pine in Glacier National Park; photo by National Park Service

The benefits that some non-native – even invasive – species provide to some groups of people do not mitigate or undo their negative impacts broadly, including to the global commons. The report authors note that beneficiaries usually differ from those people or sectors that bear the costs. The authors cite many resulting inequities.
There are insufficient studies of, or data from, aquatic systems, and from Africa; Latin America and the Caribbean; and parts of Asia.
The number of alien species is rising globally at unprecedented and increasing rates. There are insufficient data specifically on invasive species, but they, too, are thought to be rising at similar rates.
Horticulure is a major pathway for introducing 46% of invasive alien plant species worldwide.
Regarding invasive species’ greater impact on islands,the IPBES report mentions brown tree snakes on Guam and black rats on the Galapagos Islands. It also notes that on more than a quarter of the world’s islands, the number of alien plants exceeds the total number of native ones. See my blogs on non-native plants on Hawai`i and Puerto Rico. In addition, I have posted several blogs regarding disease threats to rare bird species in Hawai`. The IPBES report does not mention these.

Where the Report Is Weak: Interim Steps

The report endorses adoption of regulated species (“black”) lists.
The report emphasizes risk analysis of species. Unfortunately IPBES’ analysis was completed before publication of the critique of risk analysis methods by Raffa et al. ( (2023) (see references). However, we must take the latter into consideration when deciding what to advocate as U.S. policy.
The report authors call for more countries to adopt national legislation or regulations specifically on preventing and controlling invasive species. (They note that 83% of countries lack such policies). They also list the many international agreements that touch on invasive species-relevant issues. However, Raffa et al. found that the number of such agreements to which a country is a party bears no relationship to the numbers of alien species detected at its border or established on its territory.
The challenge to risk assessment posed by multiple sources of uncertainty can be managed by recognizing, quantifying, and documenting the extent of that uncertainty.

Beech leaf disease – one of many non-native pests that were unknown before introduction to a naive ecosystem. Photo by Jennifer Koch, USDA Forest Service

I appreciate the report’s emphasis on the importance of public awareness and engagement, but I thought the discussion of effective campaigns lacked original ideas.

The report did not fulfill its own goal of fully exploring unappreciated impacts of policies in its discussion of habitat fragmentation. For example, the report notes that grazing by feral alien ungulates facilitates the spread of invasive alien plant species. However, it does not mention the similar impact by livestock grazing (Molvar, et al. 2024).

SOURCES

Molvar, E.M., R. Rosentreter, D. Mansfield, and G.M. Anderson. 2024. Cheat invasions: History, causes, consequences, and solutions. Hailey, Idaho: Western Watersheds Project, 128 pp.

Raffa, K.F., E.G. Brockerhoff, J-C. GRÉGOIRE, R.C. Hamelin, A.M. Liebhold, A. Santini, R.C. Venette, and M.J. Wingfield. 2023. Approaches to forecasting damage by invasive forest insects and pathogens: a cross-assessment. BioScience 85 Vol. 73 No. 2 (February 2023) https://academic.oup.com/bioscience

Posted by Faith Campbell

www.fadingforests.org

Container numbers, origins, routes & destinations change — as do pest risks

container ship at Port of Savannah; photo by F.T. Campbell

Import Volumes in 2023

U.S. imports in 2023 fell about 13% from 2022 levels, returning to approximate pre-pandemic 2019 levels (Mongelluzzo 2024). The 2023 total was 24.2 million TEUs, (a united equal to twenty-foot container) compared to nearly 28 million TEUs in the previous two years (JoC.com February 2024). Imports from Asia in 2023 totalled 16.2 million TEUs. This was above the 2019 level (15.9 million TEUs) but below the more than 18.5 million TEUs in 2022 and 2021 (Mongelluzzo 2024).

This decline in imports from Asia reflected trends in the first months of 2023. This trend reversed sharply in October; during that month, containerized imports were 12.4% higher than in October 2022, even 1.1% higher than in pre-COVID October 2019 (Mongelluzzo, 2023). The upward trend continued through November: U.S. imports from Asia that month were 10.8% higher than the same month in 2022 (Journal of Commerce).

New Shipping Routes = More Possible Pests

chir pine (*Pinus roxburghii*) – a 5-needle pine native to the Himalaya in India; photo by Treesftf via Flickr

Proposed new shipping routes will expand the range of pests that can be introduced to eastern ports. For example, in November 2023, the Indian company Ocean Network Express announced plans to begin direct shipments from India to the Ports of New York-New Jersey, Savannah, Jacksonville, Charleston, and Norfolk. Expected cargo includes electronics, apparel, textiles, and foods. (Angell, 2023a) Have USDA authorities evaluated what pest species might be introduced from India?

Traders also expect rising trade volumes from South America in response to shifts in supply chains. Industries include textiles, pharmaceuticals, renewable energy, information technology, and agriculture.

The U.S. is importing more chilled produce from the west coast of South America to meet demand when these fruits are out-of-season in the U.S. The number of refrigerated containers rose to 395,572 TEUs (equivalents of twenty-foot containers). (Knowles. 2023) The Port of Savannah is actively courting these imports; it can now handle more than 3,000 refrigerated containers at one time and is expanding its capacity (Griffis 2023). Chile has a Mediterranean climate similar to that of California; Dr. Mark Hoddle reports several pests of avocado are found in neighboring Peru.

blueberries in Chile; Jardin Botanico Nacional, Chile via Flickr

Problems in the canals likely to push trade from Asia back to California ports

In an editorial published on January 25, 2024, The Washington Post reports that drought has caused water levels in the Panama Canal to fall below what is needed to operate the locks. In normal years, about 5% of global maritime trade passes through the canal. This includes nearly half the containers shipped from northeast Asia to the eastern United States. The reduction in numbers of ships moving through the Canal has affected supply chains in agriculture and energy. The situation is further complicated by wars in the Middle East hampering shipments through the Suez Canal.

The Post describes the Panamanian government’s efforts to buttress the canal, which is a major source of income. Droughts elsewhere are also impeding transport, e.g., the Amazon, Rhine, and Mississippi rivers. In the Post’s view, “threats to global growth will make it harder to … respond to poverty and hunger. … Ultimately, prevention, by arresting the emission of planet-warming greenhouse gases, is the only way to stop the list of looming climate-related threats to the global economy from getting even longer.”

Here, my focus is on what this means for volumes of ships and containers visiting ports in the eastern United States – and the associated risks of pest introductions.

Ambitious Plan for Eastern Ports

As I have pointed out in previous blogs [on the website home page, scroll below the “Archives” to “Categories”, click on “wood packaging”, especially this one], ports in eastern and Gulf Coast states have been eagerly conducting dredging operations and making other preparations to attract large container ships bringing goods from Asia. As of just a few months ago, several ports had ambitious plans. The Port of Virginia will reach a depth of 55 feet this year (Angell, 2023b). The Port of Charleston already has a 52-foot depth. Nevertheless, the port authority hopes to further deepen the channel so that it can quintuple its capacity over a decade — from 500,000 TEUs to 2.5 million TEUs (Anonymous, 2024). The Port of New York-New Jersey has approved $19 million to study deepening the ship channels from 50 to 55 feet. The Port Authority hopes to persuade Congress to share the costs (Angell, 2023b). None of the reporting mentions any consideration of the possible pest risk despite past disasters – e.g., introduction of the redbay ambrosia beetle to Savannah or Asian longhorned beetle to Charleston.

redbay mortality in Claxton, GA; photo by Scott Cameron

The proportion of total U.S. imports going to West Coast ports in 2023 was 53.6% (Mongelluzzo, 2023). Journal of Commerce’ long-time analyst Bill Mongelluzzo expects the effective closure of both the Suez (attacks on shipping) and Panama canals will push more imports from Asia to the Ports of Los Angeles and Long Beach. These linked ports now handle 32% of all U.S. imports. Mongelluzzo expects the increased volume to create new congestion problems (Mongelluzzo 2024).

containers at Long Beach in early 2000s; photo courtesy of Port of Long Beach

SOURCES

Angell, M. 2023a. ONE readies Indian-U.S. East Cost service as part of 2024 network rollout. Journal of Commerce. November 27, 2023.

Angell, M.2023b. NY-NJ port takes next steps to study dredging amid larger ship calls. Journal of Commerce December 20, 2023. https://www.joc.com/article/ny-nj-port-takes-next-steps-study-dredging-amid-larger-ship-calls_20231220.html?utm_source=Eloqua&utm_medium=email&utm_campaign=CL_JOC%20Daily%2012%2F21%2F23%20Non-Subscriber_PC00000_e-production_E-165003_DS_1221_0617

AnonymoU.S.. SC Ports requests study to deepen channel leading to North Charleston Terminal. Journal of Commerce Daily Newswire. January 12, 2024

Griffis, T.E. 2023. New ZIM service takes advantage of Savannah’s expanding cold storage network. Journal of Commerce. September 22, 2023.

Hoddle. M.S. 2023. A new paradigm: proactive biological control of invasive insect pests. BioControl https://doi.org/10.1007/s10526-023-10206-5

Knowles, G. 2023. Sourcing shift caU.S.es surge in South American logistics investment. Journal of Commerce. September 25, 2023.

Mongelluzzo, B. 2023. U.S. imports from Asia hit 2023 high in October despite muted peak season. Journal of Commerce.

Mongelluzzo, B. 2024. U.S. imports from Asia fell near pre-COVID levels in 2023, but uncertain ’24 awaits. Journal of Commerce. January 19, 2024.

Imports from Asia rise; perhaps 2,000 or more containers carrying insect pests enter U.S. in one month

Wood packaging – crates, pallets, spools for wire, etc. — has been recognized as a major pathway for introduction of tree-killing pests since the Asian longhorned beetle was detected in New York and Chicago in the late 1990s. As of 2021, 65 new species of non-native wood- or bark-boring Scolytinae had been detected in the United States (Rabaglia; full citation at end of the blog).

As I have often reported [To see my 40+ earlier blogs about wood packaging material, scroll down below archives to “Categories,” click on “wood packaging”.], the international phytosanitary community adopted the International Standard for Phytosanitary Measures (ISPM) #15. The goal of ISPM#15 is to “significantly reduce” [not eliminate] the risk of pests associated with solid wood used for constructing packaging (e.g., crates, pallets), from being introduced to other countries through international trade.

I recently reviewed the first 20+ years of implementation of ISPM#15 including two analyses by Robert Haack and colleagues in a blog in December 2022. I have also provided the broader context of the World Trade Organization (WTO) in my Fading Forests II report.

I last blogged about U.S. import volumes in June. My silence since reflected the significant decline in U.S. imports from Asia. This reduction had reduced the likelihood that a new tree-killing pest would be introduced from that region – or that an already-established pest would be introduced to a U.S. region that had escaped it so far.

However, U.S. imports from Asia have suddenly grown! In October 2023, containerized imports from Asia were 12.4% higher than a year ago – and 6% higher than in September. According to the Journal of Commerce (full citation at end of blog), U.S. retailers anticipate consumers will purchase lots of gifts for the upcoming Christmas season.

The U.S. imported 1.57 million TEU from Asia in October. This volume exceeded even the pre-COVID levels. How great is the associated risk of a pest introduction? To calculate that, I apply the following:

most U.S. imports arrive in 40-foot-long containers, so divide TEU by 2 = 785,000
a decade-old estimate that 75% of containers in maritime shipments contain wood packaging (Meissner et al.) = 588,750 containers with wood packaging (I suspect it is more).
the estimate by Haack et al. 2014 that 0.1% (1/10^th of 1 percent) of consignments (which usually means a single container) harbor tree-killing pests;
the estimate by Haack et al. 2022 that 0.22% of consignments harbor tree-killing pests.

The result of these calculations is an estimate of 648 containers (using the 2009 global estimate), or 1,727 containers (using the 2022 global estimate), or 5,730 containers (using the 2010-2020 estimate for China specifically) entering the country in one month harbored tree-killing pests. Since West Coast ports received 54% of those containers, the estimated number of containers transporting pests that enter California, Washington, or Oregon ranged from 349 to 3,042. The rest are scattered among the dozens of ports on the East and Gulf coasts.

With drought limiting container ship transits through the Panama Canal (Szakonyi 2023), the threat to East and Gulf coast ports might not rise commensurately.

Because of the low levels of imports in previous months, U.S. imports from Asia remain significantly below levels in previous years: 16.6% lower for the January – September period compared to 2022.

The 2022 analysis found that the rate of wood packaging from China that is infested has remained relatively steady since 2003: 1.26% during 2003–2004, and ranged from 0.58 to 1.11% during the next three time periods analyzed. Packaging from China made up 4.6% of all shipments inspected, but 22% of the 180 consignments with infested wood packaging. Thus the proportion of Chinese consignments with infested wood is five times greater than would be expected based on their proportion of imports. Note the great impact of this high infestation rate on the number of containers transporting tree-killing pests to the U.S. in the paragraph above: more than 8,000 containers compared to about 2,000.

I remind you that the U.S. and Canada have required treatment of wood packaging from China since December 1998. Why are the responsible agencies in the United States not taking action to correct this problem? [which has persisted for 2 decades]

The fact is – as I have argued numerous times — a pallet or crate bearing the ISPM#15 mark has not proved to be a reliable indicator as to whether the wood is pest-free. (This might be because the wood had not been treated, or if it was, the treatment failed). All the pests detected in the Haack et al. studies (after 2006) were in wood packaging bearing the ISPM#15 mark. As noted in my past blogs [click on the “wood packaging” category to bring up blogs about wood packaging and enforcement], Customs and Border Protection also report that nearly all the wood packaging in which that they detected insect pests bore the ISPM#15 mark.

According to Angell in November (full citation at end of blog), U.S. imports from India to the east coast fell by 15% in the first 10 months of 2023 compared to last year – to a total of 623,356 TEUs. This might change in the future: a shipper has promised to start weekly arrivals from India beginning in May 2024. the company plans calls at New York-New Jersey, Savannah, Jacksonville, Charleston, and Norfolk. The ships will call, en route, at ports in Saudi Arabia, Egypt, and Spain. What pests might be hitching a ride on these shipments?

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

Haack RA, Hardin JA, Caton BP and Petrice TR. 2022. Wood borer detection rates on wood packaging materials entering the United States during different phases of ISPM#15 implementation and regulatory changes. Frontiers in Forests and Global Change 5:1069117. doi: 10.3389/ffgc.2022.1069117

Meissner, H., A. Lemay, C. Bertone, K. Schwartzburg, L. Ferguson, L. Newton. 2009. Evaluation of pathways for exotic plant pest movement into and within the greater Caribbean Region.

Mongelluzzo, B. 2023. U.S. imports from Asia hit 2023 high in October despite muted peak season. Journal of Commerce https://www.joc.com/article/us-imports-asia-hit-2023-high-october-despite-muted-peak-season_20231116.html (access limited to subscribers, unfortunately)

Angell, M. 2023. ONE readies India-US East Coast service as part of 2024 network rollout. Journal of Commerce. November 27, 2023

Rabaglia, R. 2021. The increasing number of non-native bark and ambrosia beetles in North America. International Union of Forest Research Organizations. Prague, Czech Republic. September 2021

Szakonyi, M. 2023. Carriers Weigh Options as Panama Canal restrictions become fact of life. Journal of Commerce. November 21, 2023. (Access limited to subscribers, unfortunately)

Posted by Faith Campbell