valley oak at Jack London State Park (24 miles from Calistoga)
In November, scientists discovered a new ambrosia beetle in symptomatic valley oaks (Quercus lobata) trees in Calistoga, Napa County. Some blue oaks (Q. douglasii) have also been attacked (Rabaglia et al. 2020). Trees associated with this outbreak showed wilting, defoliation, and broken branches. The infested wood was discolored, presumably by the fungus. The insect, Xyleborus monographus, is native to Europe.
Officials now know that this beetle is found throughout a 15-mile-long area in Napa and neighboring Lake and Sonoma counties. It has probably been there for several years (Rabaglia et al. 2020). One specimen of the beetle was trapped in Portland, Oregon in 2018, but no infestation was detected. The beetle has never been intercepted in California. Nor has it been found in traps designed to detect bark beetles which have been deployed in 11 counties – including several in the San Francisco Bay area but not including Napa or Sonoma.
Like
all Xyleborus, adult females tunnel
into tree’s trunks, carrying fungal spores in their mycangia (structures in the
jaws in which microbes are harbored). Beetle larvae eat the fungi. Beetle
reproduction is facilitated by sibling mating within the gallery and by the
ability of unmated females to produce male offspring.
Sometimes
the beetle’s associated fungi are pathogenic to living trees. One of the fungal
species detected in the Calistoga infestation is Raffaelea montetyi, which is reported to be pathogenic to cork oak.
The presence of this fungus had been reported in 2018, although the beetle
species carrying it was not identified then. This is apparently the first report
of this fungus in North America.
Known
hosts of beetle X. monographus include
European or Eurasian chestnut (Castanea
sativa), beech (Fagus orientalis),
and European and American oaks (including
Q. lobata and Q. rubra). The possible effects of the beetle and
associated fungi on other oak species is unknown. Oaks are acknowledged to be important
components of forests and woodlands in California. Ambrosia beetles often attack
stressed trees. Since California forests are increasingly frequently stressed
by drought, fire, and other pests, they might be especially vulnerable.
The California Department of Food and Agriculture is currently seeking comments on what pest rank to assign the insect. The comment period closes on March 6th and I encourage you to consider providing your views.
In
their draft document ranking risk, state officials note that a proven host — Q. lobata — is widespread in California
and the insect is probably capable of establishing over much of the state. The possible
economic impact was described as possibly affecting production of oaks in California
nurseries and triggering quarantines. (Does
this mean CDFA expects impacts only on saplings? Is this realistic? CDFA made
no mention of costs to urban areas for hazard tree management.)
The risk assessment notes that research by McPherson, et al. (2008) found that ambrosia beetles are attracted to oak trees already infected with sudden oak death (SOD) (Phytophthora ramorum). Therefore, X. monographus could have a synergistic impact with SOD on California oaks – which has already killed an estimated 1.9 to 3.3 million coast live and Shreve oaks.
SOURCE
Rabaglia, R.J. S.L. Smigh, P. Rurgman-Jones, M.F. Digirolomo, C. Ewing, and A. Eskalen. 2020. Establishment of a non-native xyleborine ambrosia beetle, Xyleborus monographus (Fabricius) (Coleoptera: Curculionidae: Scolytinae), new to North America in California. Zootaxa 478 (2): 269-276
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 more than a decade, most countries in the world have required that crates, pallets, spools, and dunnage made from wood be treated in accordance with the requirements of the International Standard for Phytosanitary Protection (ISPM)#15 that
this treatment be certified by applying an approved stamp to the wood. The goal
of the program is to “reduce significantly the risk of introduction and spread
of most quarantine pests that may be associated with that material.”
However,
experience and studies in both the United States and Europe demonstrate that the
ISPM#15 stamp is not a reliable indicator of whether the wood packaging is
pest-free.
1) In the United States, over a period of nine years – Fiscal Years 2010 through 2018 – U.S. Customs and Border Protection (CBP) detected 9,500 consignments harboring a pest in a regulated taxonomic group. Of the shipments found with infested wood packaging, 97% bore the ISPM#15 mark (See Harriger reference at the end of the blog). The wood packaging was from nearly all trading countries. 2) In the past two years, CBP inspectors have repeatedly found pests in dunnage bearing the ISPM#15 mark – as reported by U.S. importers of “break bulk” cargo into Houston. While most of the criticism of non-compliant wood packaging refers to countries in Asia and the Americas, at least one of the Houston importers obtains its dunnage in Europe.
3)
In Europe, a two-year intensive survey of wood packaging associated with
shipments of stone from China to the 28 European Union countries over the period
2013-2016 again found that 97.5% of
consignments found to harbor pests bore the ISPM#15 mark (Eyre et al. 2018). The scientists concluded
that the ISPM-15 mark was of little
value in predicting whether harmful organisms were present. (Eyre et al. 2018, p. 712)
As I have noted in previous blogs and policy briefs, the only in-depth study of the “approach rate” of pests in wood packaging, based on data which is now a decade old, found that 0.1% of incoming wood packaging transported a regulated pest (Haack et al. 2014). Given current trade volumes, as many as 17,650 containers per year (or 48 per day) transporting tree-killing insects might be entering the U.S. (My calculation of this estimate is explained in the blog on “risks of introduction” here.)
The
Haack study excluded imports from Mexico, Canada, and China. The first and
third countries have records of poor compliance with ISPM#15 requirements, so
the “approach rate” for all incoming shipments might well have been higher.
The
study of European imports focused on shipments of stone from China – which were
deliberately chosen to represent types of imports presenting a high risk of
transporting pests. Across Europe, over the four-year period, quarantine pests
were detected in 0.9% of the consignments – somewhat higher than the U.S.
number, as could be expected. However, there were large variations among participating
countries’ findings. Austria and France found 6.95% of consignments inspected
were infested, while half of European Union countries found none!
These differences demonstrate the importance of thorough inspections.
The data also indicate
that the problem is not decreasing. Austria detected pests in nearly one-fifth
(19.6%) of inspected shipments in 2016 – the final year of the study! However,
during that same year, only 1.5% of wood packaging lacked the ISPM#15 mark.
So How Should the
International Phytosanitary Community React to This Failure?
Data
cited in numerous studies indicate that ISPM#15 has probably succeeded in
reducing the presence of pests in wood packaging. This progress is good – but
insufficient. Our forests need further reductions.
In the meantime, however, the international standard has demonstrably failed to provide a secure method to evaluate the pest risk associated with wood packaging accompanying any particular shipment. The presence of the stamp on pieces of wood packaging does not reliably show that the wood is pest-free. Officials need to determine why. Is it fraud? That would mean deliberately placing the stamp on wood that had not been treated, which U.S. CBP staffers think is occurring (Harriger). The European Union audit team that visited China also thought they detected instances of fraud. They concluded that “the current system of official controls in China does not adequately ensure that SWPM which forms part of consignments of goods exported to the EU is marked and treated according to ISPM No. 15” (Eyre et al. 2018, p. 713). On the other hand, the US importers in Houston say they are pressing their European suppliers to provide pest-free dunnage.
What
more could we ask them to do to ensure that they are not receiving fraudulently
marked materials?
Perhaps
the problem has a different cause. Are the treatments themselves are less
effective than expected? One APHIS study found that twice as many larvae reared
from wood treated by methyl bromide fumigation survived to adulthood than
larvae reared from heat-treated wood; the reason is unclear (Nadel et al. 2016). Unfortunately, it is
apparently impractical to determine whether wood was heat treated by looking
for changes in the chemical profile of the wood (Eyre et al. 2018).
Nor
can we expect inspection of 100% of all risky consignments or detection of 100%
of quarantine pests in those consignments that are inspected. Therefore, the
European study authors concluded that inspection is best considered as a means
of gathering evidence of risk and a deterrent rather than a means of completely
preventing pest movement (Eyre et al.
2018).
The
European study authors called for review of ISPM#15 as a control system and to
investigate compliance at the source (Eyre et
al. 2018 p. 714).
What is APHIS
doing?
As I have noted previously – here and here – while U.S. CBP adopted a policy in 2017 under which it can penalize importers for each consignment not in compliance with ISPM#15, APHIS has not followed Custom’s lead on this. Instead, APHIS will apply a penalty only when an importer has accrued five violations over the period of a year. (The two agencies are acting under separate legal authorities.) This is yet another example of APHIS taking a less protective stance – as I described in earlier blogs.
Since
Customs is now applying the letter of the law, the most useful step would
probably be for APHIS (and the USDA Foreign Agriculture Service) to ramp up
efforts to assist U.S. importers which are trying to comply. The importers are
begging USDA to provide better information to them about foreign suppliers of wood
packaging and dunnage. Which have good vs.
poor records? USDA could also help importers trying to complain about specific
shipments to the exporting countries’ National Plant Protection Organizations
(NPPOs; departments of agriculture). In
addition, APHIS could augment its pressure on foreign NPPOs and the
International Plant Protection Convention more generally to ascertain the
reasons ISPM#15 is failing and to fix the problems.
APHIS has not been idle. The North American Plant Protection Organization (including Canada and Mexico) has sponsored two workshops intended to educate NPPOs and exporters in Asia and the Americas about the standard’s requirements. APHIS is planning to address wood packaging in an international symposium organized under the auspices of the International Year of Plant Health in July 2020 – I will provide details when they become available.
APHIS is collaborating with the Entomological Society of America to host a workshop on wood packaging at the ESA annual meeting in November 2020 – I will provide details when they become available. The Continental Dialogue on Non-Native Forest Insects and Diseases plans to link its annual 2020 meeting to this workshop.
More immediately, the Continental Dialogue on Non-Native Forest Insects and Diseases will have presentations on the wood packaging issue at its annual meeting in just 11 days! in Cleveland
In preparation for the 2020 meetings, APHIS should fund more studies and audits of wood packaging to document the current efficacy of the standard (that is, the pest approach rate); remember, Haack’s study relied on data which are now a decade old. Not only has time passed … Both the standard and U.S. enforcement policies have changed since 2009.
Significance of the
Wood Packaging Problems
The
apparent failure of the ISPM#15 standard to provide a reliable means to certify
treatment raises obvious issues regarding the risk of pest introductions.
However, the implications are much broader.
The premise of the international phytosanitary system – the Agreement on the Application of Sanitary and Phytosanitary Standards (SPS Agreement) and International Plant Protection Convention (IPPC) – is that importing countries should rely on exporting countries to take the actions necessary to meet the importing countries’ plant health goals. The ISPM#15 experience casts doubt on this premise. The exporters are not reliably ensuring the cleanliness of their wood packaging. Worse, wood packaging is easier to treat than fruits, vegetables, and living plants (plants for planting). The latter commodities are much more easily damaged or killed by treatments than are boards or even logs – which are, after all, already dead! (A longer discussion of the SPS Agreement and IPPC is found in Chapter III of Fading Forests II, available here.
I
hope that the international phytosanitary community will take advantage of the
heightened attention and effort associated with the International Year of Plant
Health in 2020 to re-examine all aspects of the current global phytosanitary system.
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.
SOURCES
Eyre,
D., R. Macarthur, R.A. Haack, Y. Lu, and H. Krehan. 2018. Variation in
Inspection Efficacy by Member States of SWPM Entering EU. Journal of Economic
Entomology, 111(2), 2018, 707–715)
Nadel,
N., S. Myers, J. Molongoski, Y. Wu, S. Linafelter, A. Ray S. Krishnankutty, and
A. Taylor. 2016. Identificantion of Port Interceptions in Wood Packaging
Material: Cumulative Progress Report, April 2012 – August 2016
It
is widely recognized that invasions of non-native species occur as a
consequence of international trade (see Seebens et. al. 2017 – full citations at the end of this blog). This is as
true for non-native forest pests as for any other bioinvader – see Aukema et al. 2010; Liebhold et al. 2012, Lovett et al. 2016. In fact, gross domestic product – as an indicator of levels
of trade — is a better predictor of the number of forest pest invasions in a
given country than the country’s amount of forested land (Roy et al. 2014).
shipping containers at port of Long Beach, California
As I noted in my previous blog, I began studying and writing about the threat to North America’s forests from non-native insects and pathogens in the early 1990s. I reported my analyses of the evolving threat in the three “Fading Forests” reports – coauthored by Scott Schlarbaum – in 1994, 2003, and 2014. These reports are available here.
I document here that both introduction
and spread of pests within the country have continued apace. While significant
efforts have been made to prevent introductions (described briefly under the
“Invasives 101” tab of the CISP website), they have fallen short. As I noted in
Fading Forests III, programs aimed at preventing spread of pests within the
country remain fragmented and often are unsuccessful.
The Challenge: Huge Volumes of goods are moving, providing
opportunities for pests
Since 1990, volumes of imported goods more than quintupled. Within the U.S., a total of 17,978 million tons of goods were transported in 2015; 10,776 million tons of this total by truck. About one-third of this total – 5,800 million tons – was moved farther than 250 miles. These vehicles moved on a public roads network of 4,154,727 miles (US DOT FFA). Consequently, once a pest enters the U.S., it can be moved quickly into every corner of the country.
Introductions
By and large,
establishment of tree-killing pests has occurred at a fairly steady rate of
about 2.5 per year, with “high-impact” insects and pathogens accumulating at
0.43 per year (Aukema et al. 2010). Since
introductions did not rise commensurately with rising import volumes, Lovett et al. (2016) concluded that the
recently adopted policies for preventing introductions referenced above are
having positive effects but are insufficient to reduce the influx of pests in
the face of ever-growing global trade volumes. The study’s authors went on to
say that absent more effective policies, they expect the continued increase in
trade will bring many new establishments of non-native forest pests.
One group of forest
pests did not enter at a steady rate, but rather entered at a higher rate since
1985 – wood-boring insects. Experts concluded that the increase probably
reflected increases in containerized shipping (Lovett et al. 2016). At the global level, the rate of fungal invasions has
also recently been reported to be increasing rapidly (Roy et al. 2014).
Asian longhorned beetle
Geography of trade
patterns also matters. Opening of trade with China (in 1979) offered
opportunities for pests from a new source country which has a similar climate
and biology. Roy et al. describe the importance of phylogenetic
relatedness of pests and of tree hosts in explaining tree species’ vulnerability
to introduced pests. The most vulnerable forests are those made up of species
similar to those growing in the source of the traded goods – i.e., the temperate forests of the
northeastern U.S. – when goods are imported from similar forested areas of
Europe and Asia. Chinese-origin wood-boring pests began to be detected around
1990. This already short interval probably underestimates how quickly pests
began arriving; detection methods were poor in those years, so a pest was often
present for close to a decade before detection.
Between 1980 and 2016, at least 30 non-native species of wood- or bark-boring insects in the Scolytinae / Scolytidae were newly detected in the United States (Haack and Rabaglia 2013; Rabaglia et al. 2019). Over the same period, approximately 20 additional tree pests were introduced to the continental states (Wu et al. 2017; Digirolomo et al. 2019; R. Haack, pers. comm.) plus about seven to America’s Pacific islands. Not all of the new species are highly damaging, but enough are. See my previous blog here.
Many of the tree-killing
pests were probably associated with pathways other than wood packaging. These
include 6 of the 7 Agrilus species, sudden oak death pathogen, three pests of palm trees, the
spotted lanternfly, beech leaf disease; and the pests introduced to America’s
Pacific Islands.
HIGH-RISK
PATHWAYS OF INTRODUCTION
Already
in the 1990’s it was evident that better preventing pest introductions would
depend on shutting down the variety of pathways by which they move around the
world. At that time, attention focused on imports of
logs and nursery stock (nursery stock makes up one component of a broader
category called by phytosanitary agencies “plants for planting”). Both logs and
“plants for planting” had well-established histories of transporting pests and
import volumes were expected to grow. We have since learned that there are many
more pathways!
Plants for Planting
Imports of “plants for planting” (phytosanitary agencies’ term, which encompasses nursery stock, roots, bulbs, seeds, and other plant parts that can be planted) have long been recognized as a dangerous pathway for introduction of forest pests. For example, this risk was the rationale for adopting the 1912 Plant Quarantine Act. Charles Marlatt, Chairman of USDA’s Federal Horticultural Board (see “Then and Now” in Fading Forests III here), wrote about the risk in National Geographic in April 1911 (urging adoption of the 1912 law) and again in August 1921. See also Brasier (2008), Roy et al. (2014), Liebhold et al. (2012), Jung et al. (2016).
Japanese cherry trees being burned because of scale infestation January 28, 1910; Agriculture Research Service
Of the 91 most
damaging non-native forest pest species in the U.S. (Guo et al. 2019), about 62% are thought to have entered North America
with imports of live plants. These include nearly all the sap-feeding insects,
almost 90% of the foliage-feeding insects, and approximately half of the
pathogens introduced during the period 1860-2006 (Liebhold et al. 2012). Specific examples include chestnut blight, white pine
blister rust, Port-Orford-cedar root disease, balsam woolly adelgid, hemlock
woolly adelgid, beech scale, butternut canker, dogwood anthracnose, and sudden
oak death. In more recent years, introductions via this pathway possibly
include ‘ōhi‘a
rust, rapid ‘ōhi‘a death pathogens, and beech leaf disease. The gypsy
moth, while a foliage feeder, was not introduced via imports of live plants.
The
APHIS annual report for 2018 reported that in that year we imported 18,502
shipments containing more than 1.7 billion
plant units (plants, bulbs, in vitro materials, etc.).
Liebhold et al. 2012, relying on 2009 data, found that about 12 percent of incoming plant shipments had symptoms of pests – a rate more than 100 times greater than that for wood packaging. Worse, a high percentage of the pests associated with a shipment of plants is not detected by the federal inspectors. The meaning of this finding is unclear because the study did not include any plant genera native to temperate North America and APHIS points out that infestation rates varied considerably among genera in the study. However, APHIS has not conducted its own analysis to document the “slippage rate” on imports of greatest concern to forest conservationists, i.e., imports of woody plants. I provide details on pests detected on imports of woody plants in recent in my blog here.
Clearly the risk of pest introductions continued at least until recently. I reviewed an APHIS database listing pests newly detected in the country during the period 2009-2013. I concluded that approximately 37 of the 90 “new” pests listed in the database (viruses, fungi, aphids and scales, whiteflies, mites) were probably introduced via imports of plants, cuttings, or cut foliage or flowers. I discussed these matters in greater detail here.
Adoption of a new regulatory regime governing imported plants for planting (Q-37 regulation) in 2018 is too recent to for us to see its impact. But the new regulation sets up a process under which APHIS can impose more protective regulations on specific types of plants or plants from certain countries of origin to counter a perceived concerning level of risk. Until APHIS begins activating its new powers by negotiating more protective regulations governing plant imports from high-risk sources, it seems unlikely there will be any meaningful change in the introduction rates.
Crates, Pallets,
and Other Forms of wood packaging (solid wood packaging, or SWPM)
Recognition
of the risk associated with wood packaging is much more recent. In 1982, a USDA
risk assessment concluded that the wood boring insects found in crates and
pallets were not of great concern (USDA APHIS and Forest Service, 2000).
However, contradictory indications were quickly documented – including from
APHIS’ own port interception data – which the agency began collecting in 1985. Over
the 16-year period 1985-2000, 72%
of
the 6,825 bark beetles (Scolytidae)
intercepted by APHIS were found on SWPM (Haack 2002). Cerambycids (longhorned
beetles) and buprestids (jewel beetles) make up nearly 30% of insects detected
in wood packaging over the last 30 years (Haack et al. 2014).
Detection
of outbreaks of the Asian longhorned beetle and other woodborers in the
mid-1990s made it clear that wood packaging was, indeed, a high-risk pathway.
Of
the 91 most damaging non-native pest species in the US, 30% probably arrived
with wood packaging material or other wood products (Liebhold et al. 2012). This group includes many
of the most damaging pests, the deadly woodborers – Asian longhorned beetle,
emerald ash borer, redbay ambrosia beetle,
possibly the polyphagous and Kuroshio shot hole borers.
CBP agents inspecting a pallet
As noted above, introductions of wood borers have risen in recent decades, widely accepted as associated with the rapid increase in containerized shipping after 1980. In 2009 it was estimated that 75% of maritime shipments were packaged in crates or pallets made of wood (Meissner et al. 2009). A good history of the global adoption of containerized shipping is Levinson, M. The Box: How the Shipping Container Made the World Smaller and the World Economy Bigger (Princeton University Press 2008)
The simultaneous
opening of trade with China (in 1979) offered opportunities for pests from a
new source country which has a similar climate and biology. Chinese-origin wood-boring
pests began to be detected around 1990. This already short interval probably underestimates
how quickly pests began arriving; detection methods were poor in those years,
so a pest was often present for close to a decade before detection.
I have already documented numerous times that, despite the U.S.’ implementation of the International Standard of Phytosanitary Measures (ISPM) #15 in 2006, live quarantine pest woodborers continue to enter the U.S. in wood packaging. The best estimate is that 0.1% of wood packaging entering the United States is infested with wood-borers considered to be quarantine pests (Haack et al. 2014). More than 22 million shipping containers entered the U.S. via maritime trade in 2017 (US DoT). As noted, an estimated 75% of sea-borne containers include wood packaging. Applying the 0.1% estimate to these figures results in an estimate that as many as 17,650 containers per year (or 48 per day) transporting tree-killing insects enter the U.S.
Over a period of
nine years – Fiscal Years 2010 through 2018 – U.S. Customs and Border
Protection (CBP) detected more than 28,600 shipments with wood packaging that
did not comply with ISPM#15 (Harriger presentations to the annual meetings of
the Continental Dialogue on Non-Native Forest Insects and Diseases). While most
of the non-compliant shipments were wood packaging that lacked the required
mark showing treatment per ISPM#15,
in 9,500 cases the wood packaging actually harbored a pest in a regulated
taxonomic group.
Disturbingly, 97%
of the shipments that U.S. CBP found with infested wood packaging bear the
ISPM#15 mark certifying that wood had been fumigated or heat-treated (Harriger
2017). CBP inspectors tend to blame this on widespread fraud in use of the mark.
On the other hand, one study found that larvae can survive both treatments –
although the frequency of survival was not determined. It was documented that twice
as many larvae reared from wood treated by methyl bromide fumigation survived
to adulthood than larvae reared from heat-treated wood; the reason is unclear
(Nadel et al. 2016).
The APHIS’ record
of interceptions for the period FYs 2011 – 2016 contained 2,547 records for
insect detections on wood packaging. The insects belonged to more than 20
families. Families with the highest numbers of detections were Cerambycids –
25% of total; Curculionidae – 23% (includes Dendroctonus,
Ips, Orthotomicus, Scolytinae, Xyleborus, Euwallacea); Scolytidae – 17% (includes
true weevils such as elm bark beetles); Buprestids – 11%; and Bostrichidae –
3%. Not all of the insects in these groups pose a threat to North American
plant species.
One encouraging data point is that since 2010, there have been no detections of species of bark and ambrosia beetles new to North America in the traps deployed by the USDA Forest Service Early Detection and Rapid Response program (Rabaglia 2019). The 2014 recognition of the Kuroshio shothole borer apparently did not result from this trapping program.
There have been several changes in the wood packaging standard and its implementation by CBP since 2009, the year Haack et al. 2014 analyzed the “pest approach rate”. APHIS has not carried out a study to determine whether these recent changes have reduced the approach rate below Haack’s estimate of 0.01%. Consequently, we do not know whether these changes have reduced the risk of pest introductions.
Other Pathways That
Transport Fewer Pests – Some of Which Have High Impacts
Insects
that attach egg masses to hard surfaces can be transported by ship
superstructures, containers, and hardsided cargoes such as cars, steel beams,
and stone. While relatively few species have been moved in this way, some have
serious impacts. The principal examples are the gypsy moths from Asia, which
feed on 500 species of plants (Gibbon 1992).
The United States and Canada have a joint program – under the auspices of the North American Plant Protection Organization (see RSPM #33) aimed at preventing introduction of species of Asian gypsy moths. The NAPPO standard originally went into force in March 2012. Under its terms, ships leaving ports in those countries during gypsy moth flight season must be inspected and cleaned before starting their voyage.
Gypsy moth populations rise and fall periodically; it is much more likely that egg masses will be attached to ships during years of high moth population densities. These variations are seen in U.S. and Canadian detection reports – as reported here.
While most AGM detections are at West Coast ports, [here; and here] the risk is not limited to that region. AGM have been detected at Wilmington, NC; Baltimore, MD; Charleston, SC; Savanna and Brunswick, GA; Jacksonville, FL; New Orleans, LA; Houston and Corpus Christi, TX; and even McAlester, OK.
Nor is the risk limited to the ships themselves. In 2014, more than 500 Asian gypsy moth egg masses were found on four shipments of imported steel slabs arriving at ports on the Columbia River in Washington.
Between 1991 and 2014, AGM was detected and eradicated
on at least 20 occasions in locations across the United States (USDA AGM pest
alert). Additional outbreaks have been discovered and eradication efforts
undertaken in more recent years.
A second example is
the spotted lanternfly (SLF) (Lycorma delicatula), which was first
detected in southeast Pennsylvania in autumn 2014. It is native to Asia; it is
believed to have entered the country as egg masses on imported stone.
While SLF is
clearly a pest of agriculture – especially grapes and tree fruits – its
importance as a forest pest is still unclear. Many native forest trees appear
to be hosts during the insect’s early stages, including maples, birches,
hickories, dogwoods, beech, ash, walnuts, tulip tree, tupelo, sycamore, poplar,
oaks, willows, sassafras, basswood, and elms. Adult lanternflies strongly
prefer the widespread invasive species tree of heaven (Ailanthus altissima).
As of August 2019, SLF was established in parts of five states: Delaware, Maryland, New Jersey, Pennsylvania, and Virginia. It was detected as having spread to a 14th county in Pennsylvania; five new counties in New Jersey. APHIS is working with state departments of Agriculture in these states, as well as supporting surveys in New York, North Carolina, and West Virginia (USDA APHIS DA-2019-20, August 7, 2019). Apparently the detections of a few adults – alive or dead – in Connecticut and New York had not evolved into an outbreak. See description and map here.
Imports of logs – roundwood – seem inherently risky. Certainly Dutch elm disease was introduced via this pathway. However, there have been few pest introductions linked to this pathway in recent years, probably because we import most of our unprocessed lumber from Canada. (I provide considerable data on U.S. roundwood imports in Fading Forests III here.)
Decorative items and furniture made of unprocessed wood certainly have the potential to transport significant pests (USDA APHIS 2007). Examples include boxes and baskets; wood carvings; birdhouses; artificial Christmas trees or other plants; trellises; lawn furniture. To date, apparently, no high-impact pest has been introduced via this pathway, although pests intercepted on shipments have included Cerambycids from Asia, e.g., velvet longhorned beetle and here.
Alarmed by high numbers of infested shipments from China, APHIS first suspended imports of such items temporarily; then adopted a regulation (finalized in March 2012 – USDA APHIS 2012).
APHIS
has not taken action to prevent introductions on such items imported from other
countries – although the North American Plant Protection Action adopted a
regional standard making the case for such action and outlining a risk-based
approach (NAPPO RSPM#38).
Snails on Shipping
Containers
Snails have been
detected on shipping containers and wood packaging for decades. In 2015, APHIS
stepped up its efforts to address this risk through bilateral negotiations with
Italy and launching regional and international efforts to develop guidance for
ensuring pest-free status of shipping containers (Wendy Beltz, APHIS, presentation
to National Plant Board, 2018 annual meeting).
SPREAD
WITHIN THE UNITED STATES
Major pathways for human-assisted spread of pests within the country are sales of plants for planting, movement of unprocessed wood – especially firewood, and hitchhiking on transport vehicles. Since most forest pests are not subject to federal quarantine, any regulatory programs aimed at preventing spread depend on cooperation among the 50 states. None of these pathways is regulated adequately to prevent pests’ spread. See Chapter 5 of Fading Forests III here.
And since neither
federal nor state agencies do significant enforcement of existing regulations,
preventing spread often depends upon pest awareness of, and voluntary
compliance by, individuals and companies.
Even pests subject to a federal quarantine are not prevented from spreading. Plants exposed to the sudden oak death pathogen were shipped to 18 states in spring 2019.
SOD-infected rhododendron plant; Indiana Department of Natural Resources
A collaborative effort by the nursery industry, APHIS, and states (Systems Approach to Nursery Certification, or SANC) is striving to close gaps linked to the standard practice of inspecting plants at the time of shipping, but full implementation of this voluntary program is still years away.
Transport of firewood has been responsible for movement of pests both short distances, e.g., goldspotted oak borer in southern California; and long distances – e.g., emerald ash borer to Colorado. APHIS attempted to develop a certification program but the industry was unable to put one together (see Chapter 5 of Fading Forests III). Current federal and state regulations of firewood are tied to the emerald ash borer quarantine, which APHIS has proposed to terminate. Wood for turning and woodworking has also been linked to movement of pests, e.g., walnut twig beetle/thousand cankers disease from the west to Pennsylvania.
emerald ash borer
Truck transport of a
variety of goods has transported European gypsy moths from the infested areas
in the east to the west coast. Transport of stone probably moved spotted
lanternfly from southeastern Pennsylvania to Winchester, Virginia.
SOURCES
Aukema, J.E., D.G. McCullough, B. Von
Holle, A.M. Liebhold, K. Britton, & S.J. Frankel. 2010. Historical
Accumulation of Nonindigenous Forest Pests in the Continental United States.
Bioscience. December 2010 / Vol. 60
No. 11
Brasier, C.M. 2008. The biosecurity
threat to the UK and global environment from international trade in plants. Plant Pathology (2008) 57, 792-808
Bray, A.M., L.S. Bauer, T.M. Poland,
R.A. Haack, A.I. Cognato, J.J. Smith. 2011. Genetic analysis of emerald ash
borer (Agrilus planipennis Fairmaire)
populations in Asia and North America. Biol. Invasions (2011) 13:2869-2887
Gibbon,
A. 1992. “Asian Gypsy Moth Jumps Ship to United States.” Science.
Vol. 235. January 31, 1992.
Haack R. A. and J.F. Cavey. 1997.
Insects Intercepted on Wood Articles at United States Ports-of-Entry and Two
Recent Introductions: Anoplophora
glabripennis and Tomicus piniperda.
In press in International forest insect workshop proceedings, 18 – 21
August 1997, Pucon, Chile. Corporacion National Forestal, Santiago, Chile.
Haack, R.A., F. Herard, J. Sun, J.J.
Turgeon. 2010. Managing Invasive Populations of Asian Longhorned Beetle and
Citrus Longhorned Beetle:A Worldwide Perspective. Annu. Rev. Entomol. 2010.
55:521-46.
Haack,
R.A. and R.J. Rabaglia. 2013. Exotic Bark and Ambrosia Beetles in the USA:
Potential and Current Invaders. CAB International 2013. Potential Invasive
Pests of Agricultural Crops (ed. J. Peña)
Haack R.A., Britton K.O., Brockerhoff, E.G., Cavey, J.F.,
Garrett., L.J., 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,
R.A., F. H´erard, J. Sun, and J.J. Turgeon. 2010. Managing Invasive Populations
of Asian Longhorned Beetle and Citrus Longhorned Beetle: A Worldwide
Perspective. Annu. Rev. Entomol. 2010. 55:521–46
Harriger, K. Department of Homeland Security Bureau of
Customs and Border Protection, presentation to the Continental Dialogue on
Non-Native Forest Insects and Diseases, November 2017.
Jung T, Orlikowski L, Henricot B, et al. 2016. Widespread
Phytophthora infestations in European nurseries put forest, semi-natural and
horticultural ecosystems at high risk of Phytophthora diseases. Forest
Pathology 46: 134–163.
Liebhold, A.M., E.G. Brockerhoff, L.J. Garrett, J.L.Parke, and K.O Britton.
2012. Live plant inports: the major pathway for forest insect and pathogen invasions of the US. Frontiers in
Ecology.
Lovett, G.M., M. Weiss, A.M. Liebhold, T.P. Holmes, B.
Leung, K.F. Lambert, D.A. Orwig, F.T.
Campbell, J. Rosenthal, D.G. McCullough, R. Wildova, M.P. Ayers, C.D. Canham,
D.R. Foster, S.L. LaDeau, and T. Weldy. 2016.
Non-native forest insects and pathogens in the United States: Impacts
and policy options. Eological
Applications, 26(5) pp. 1437-1455.
Meissner, H., A. Lemay, C. Bertone, K. Schwartzburg, L.
Ferguson, and L. Newton. 2009. EVALUATION OF PATHWAYS FOR EXOTIC PLANT PEST
MOVEMENT INTO AND WITHIN THE GREATER CARIBBEAN REGION. Caribbean Invasive
Species Working Group (CISWG) and Plant Epidemiology and Risk Analysis
Laboratory (PERAL) / CPHST. June 4, 2009
Morin, R. presentation at Northeastern Forest Pest Council 81st Annual
Meeting, March 12 – 14, 2019, West
Chester, Pennsylvania
Nadel, N., S. Myers, J. Molongoski, Y.
Wu, S. Linafelter, A. Ray S. Krishnankutty, and A. Taylor. 2016.
Identificantion of Port Interceptions in Wood Packaging Material: Cumulative
Progress Report, April 2012 – August 2016
Rabaglia,
R.J., A.I. Cognato, E. R. Hoebeke, C.W. Johnson, J.R. LaBonte, M.E. Carter, and
J.J. Vlach. 2019. Early Detection and Rapid Response. A Ten-Year Summary of the
USDA Forest Service Program of Surveillance for Non-Native Bark and Ambrosia
Beetles. American Entomologist Volume 65, Number 1
Roy, B.A., H.M. Alexander, J. Davidson,
F.T. Campbell, J.J. Burdon, R. Sniezko, and C. Brasier. 2014. Frontiers in Ecology 12(8): 457-465
U.N. Food and Agriculture Organization International
Plant Protection Convention. 2012. International Standards for Phytosanitary Meaures
No. 36 Integrated Measures for Plants for planting. Rome. Online at
https://www.ippc.int/ Accessed December
7, 2012.
United States Department of Agriculture
Animal and Plant Health Inspection Service and Forest Service, 2000. Pest Risk
Assessment for Importation of Solid Wood Packing Materials into the United
States.
United States Department of Agriculture Animal and
Plant Health Inspection Service 2009. Proposed Rule Importation of plants for
planting: establishing a category of plants for planting not authorized for
importation pending pest risk assessment. Federal
Register 74(140): 36403-36414 July 23, 2009.
United
States Department of Agriculture Animal and Plant Health Inspection Service 7
CFR Parts 318, 319, 330, 340, 360, and 361. Federal Register Rules and
Regulations Vol. 83, No. 53. Monday, March 19, 2018
United States Department of Agriculture Animal and
Plant Health Inspection Service 2007. Pests and
mitigations for manufactured wood décor and craft products from China for
importation into the United States. Revision 6. July.
United States Department of Agriculture Animal and
Plant Health Inspection Service. 2012. Importation of wooden handicrafts from
China. Final rule. Federal Register 77(41):
12437-12444. March 1. Online at http://www.gpo.gov/fdsys/pkg/FR-2012-03-01/pdf/2012-4962.pdf.
Accessed August 2, 2013.
United
States Department of Transportation Bureau of Transportation Statistics Freight
Facts and Figures
United States Department of Transportation, Maritime
Administration, U.S. Waterborne Foreign Container Trade by U.S. Customs Ports
(2000 – 2017) Imports in Twenty-Foot Equivalent Units (TEUs) – Loaded
Containers Only
Williams, L.H. and J.P. La Fage. 1979.
Quarantine of Insects Infesting Wood in International Commerce. in J.A.
Rudinksy, ed. Forest Insect Survey and Control Fourth Edition 1979
Wu,Y.,
N.F. Trepanowski, J.J. Molongoski, P.F. Reagel, S.W. Lingafelter, H. Nadel1,
S.W. Myers & A.M. Ray. 2017. Identification of wood-boring beetles
(Cerambycidae and Buprestidae) intercepted in trade-associated solid wood
packaging material using DNA barcoding and morphology Scientific Reports 7:40316
USDA APHIS has formally proposed to end its regulatory program aimed at slowing the spread of the emerald ash borer (EAB) within the United States. APHIS proposes to rely on biological control to reduce impacts and – possibly – slow EAB’s spread. The proposal and accompanying “regulatory flexibility analysis” are posted here.
Public comments on this proposed change are due 19 November, 2018.
I will blog more fully about this issue in coming weeks. At present, I am on the fence regarding this change.
On the one hand, I recognize that APHIS has spent considerable effort and resources over 16 years trying to prevent spread of EAB – with less success than most would consider satisfactory. (EAB is known to be in 31 states and the District of Columbia now). While APHIS received tens of millions of dollars in emergency funding in the beginning, in recent years funding has shrunk. Over the past couple of years, APHIS has spent $6 – $7 million on EAB out of a total of about $54 million for addressing “tree and wood pests.” (See my blogs on appropriations by visiting www.cisp.us, scrolling down to “topics,” then scrolling down to “funding”). Funding has not risen to reflect the rising number of introduced pests. Presumably partly in response, APHIS has avoided initiating programs targetting additional tree-killing pests. For example, see my blogs on the shot hole borers in southern California and the velvet longhorned beetle by visiting www.cisp.us, scrolling down to “categories,” then scrolling down to “forest pest insects”. I see a strong need for new programs on new pests and money now allocated to EAB might help fund such programs.
On the other hand, APHIS says EAB currently occupies a quarter of the range of ash trees in the U.S. Abandoning slow-the-spread efforts put at risk trees occupying three quarters of the range of the genus in the country. (See APHIS’ map of infested areas here.) Additional ashes in Canada and Mexico are also at risk. Mexico is home to 13 species of ash – and the most likely pathway by which they will be put at risk to EAB is by spread from the U.S. However, APHIS makes no mention of these species’ presence nor USDA’s role in determining their fate.
I am concerned by the absence of information on several key aspects of the proposal.
APHIS makes no attempt to analyze the costs to states, municipalities, homeowners, etc. if EAB spreads to parts of the country where it is not yet established – primarily the West coast. As a result, the “economic analysis” covers only the reduced costs to entities within the quarantined areas which would be freed from requirements of compliance agreements to which they are subject under the current regulations. APHIS estimates that the more than 800 sawmills, logging/lumber producers, firewood producers, and pallet manufacturers now operating under compliance agreements would save between $9.8 M and $27.8 million annually. This appears to be a significant benefit – but it loses any meaning absent any estimate of the costs that will be absorbed by governments and private entities now outside the EAB-infested area.
ash tree killed by EAB; Ann Arbor, MI; courtesy of former mayor of Ann Arbor, MI John Hieftje
APHIS does not discuss how it would reallocate the $6 – 7 million it spends on EAB. Would it all go to EAB biocontrol? Would some be allocated to other tree-killing pests that APHIS currently ignores?
APHIS provides no analysis of the efficacy of biocontrol in controlling EAB. It does not even summarize studies that have addressed past and current releases of EAB-specific biocontrol agents. (I will report on my reading of biocontrol studies in a future blog.)
APHIS says efforts are under way to develop programs to reduce the risk of pest spread via firewood movement. APHIS does not explain what those efforts are or why they are likely to be more effective than efforts undertaken in response to recommendations from the Firewood Task Force issued in 2010.
APHIS makes no attempt to analyze environmental impacts.
champion green ash in Michigan killed by EAB
APHIS says nothing about possibly supporting efforts to breed ash trees resistant to EAB.
I welcome your input on these issues.
I will inform you of my evolving thinking, information obtained in efforts to fill in these gaps, etc. in future blogs.
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.
There is widespread agreement that the most important pathways for long-distance transport of non-native forest insects are wood packaging (crates, pallets, dunnage, etc.) and imports of live plants (which APHIS calls “plants for planting”). Sources (at end of blog): Aukema et al. 2010; Liebhold et al. 2012; Meurisse et al. 2018 and many others. See also my earlier blogs by scrolling down to the “categories” section and clicking on “wood packaging”.
According to Meurisse et al., by the middle of this decade, world maritime freight trade had reached about 10 billion metric tonnes, and air transport of cargo had reached 50 million tonnes – much of it packaged in wood.
As the world’s biggest importer, the United States receives about 27 million shipping containers each year (CBP to FT Campbell). A study carried out in 2005 – 2007 (Meissner et al. 2009) indicated that 75% of maritime shipments entering the U.S. contained wood packaging; 33% of air shipments contained wood packaging. These are significant increases over earlier estimates that put the number of containers entering the country at 25 million. An even older analysis estimated that 52% of incoming containers had wood packaging.
APHIS has recognized the pest risk associated with wood packaging for 20 years – since the Asian longhorned beetle was detected in a second city – Chicago – in 1998. APHIS and its Canadian counterpart (Canadian Food Inspection Agency) acted rapidly to adopt, first, domestic regulations governing wood packaging from China (in December 1998), then a regional standard for wood packaging, and finally to help bring about adoption of International Standard for Phytosanitary Measures (ISPM) No. 15 in 2002. A detailed description of these actions can be found in my report Fading Forests II available here.
However, as I have demonstrated often, ISPM#15 has reduced the threat – but insufficiently. Dr. Robert Haack and his coauthors (2014) found that of each thousand shipments containing wood packaging that enters the country, one harbors a quarantine pest. Applying this estimate to the current volume of incoming containers and the higher proportion containing wood packaging results in an estimate that up to 20,000 shipping containers containing infested wood packaging enter the country each year – or approximately 55 per day.
The actual approach rate might be less. There are two variables that I lack sufficient data to quantify.
First, a significant proportion of the incoming containers come from Mexico or Canada – our second and third largest trading partners. The risk of damaging pests arriving from our neighbors is less than the risk accompanying shipments from overseas – although it is not “0”. Several woodborers native to Mexico have been introduced to U.S. ecosystems and are killing trees in these new environments, e.g., goldspotted oak borer, walnut twig beetle, and soapberry borer (all described in write-ups here). It is true that these beetles were probably introduced to vulnerable parts of the U.S. in firewood rather than wood packaging. There are also reasons to be concerned about pest introductions from Canada. Threats arise from both non-native pests established in the country e.g., brown spruce longhorned beetle and European beech leaf weevil, and pests in shipments from off-shore origins that are re-packaged in Canada (Yemshanov et al. 2012 and my earlier blog from April 2017).
The second variable on which I lack data is the proportion of the 27 million containers that are transported by air, and are thus half as likely to contain wood packaging.
To account for these unknowns, I have nearly halved the number of shipping containers likely to transport pests from off-shore – so 14 million instead of 27 million. Again applying Haack’s estimate, the result is 10,500 shipping containers containing infested wood packaging entering the country every year – or approximately 29 every day.
Update with more precise data (August 24) :
Re: the two variables, I have found partial answers from a U.S. Department of Transportation website which provides data on imports of loaded chipping containers (in TEUs) for 68 ports. (For the website, go here – click on “trade statistics”, then “US Waterborne trade” (1st bullet)]
As of 2017, 22,360,941 loaded shipping containers entered the U.S. via maritime transport. Applying the estimate of 75% of these containers holding wood packaging, we find that slightly less than 17 million containers entered the country with wood packaging. Applying Robert Haack’s estimate that one in a thousand is infested with a quarantine insect, we anticipate that 17,000 of these containers were transporting a pest that threatens our country. That is 46 containers every day.
Ports which received the largest numbers of containers, according to the DoT database:
Long Beach/Los Angeles — 8.4 million containers
New York — 3.4 million containers
Savannah — 1.8
Norfolk — 1.2
Houston — 1 million containers
We need answers!
The point is, we don’t know how many pests are reaching the United States daily. Or if the current approach rate is significantly higher or lower than in the past. Despite my urging, APHIS has not undertaken a study to update Haack’s estimate – which is based on 2009 data. In the intervening nine years, several changes were made to ISPM#15 to make it more effective. The most important was restricting the size of bark remnants that may remain on the wood.
Also, we might hope that experience with implementing the standard has led to better compliance. Unfortunately, available data do not encourage belief that compliance has improved.
Customs and Border Protection (CBP) reports annually to the Continental Dialogue on Non-Native Forest Insects and Diseases on the number of import shipments with wood packaging that have been detected as not complying with ISPM#15. Over a period of eight years – Fiscal years 2010 through 2017 – CBP detected nearly 24,000 non-compliant shipments. While most (17,413) of the non-compliances were crates or pallets that lacked the required mark showing treatment in accordance with ISPM#15, in 6,388 cases the wood packaging actually harbored a pest in a regulated taxonomic group. This works out to about 800 infested shipments detected each year.
By comparing Dr. Haack’s estimate with the CBP data, I estimate that Customs is detecting and halting the importation of four to eight percent of the shipments that actually contain pest-infested wood. Since CBP inspects only about two percent of incoming shipments, this detection rate demonstrates the value of CBP’s program to target likely violators – and deserves praise. But it is obviously too low a “catch” rate to provide an adequate level of protection for our forests.
Indeed, using the older, lower estimates of both numbers of shipping containers and the proportion that contain wood packaging, Leung et al. 2014 concluded that continuing to implement ISPM#15 at the efficacy level described by Haack et al. would result in a tripling of the number of non-native wood-boring insects introduced into the U.S. by 2050.
CBP inspector views Cerambycid larvae found in wood packaging that bears ISPM#15 stamp
Closer examination of the data raises more troubling questions. On average, 97% of the 6,388 shipments containing infested wood pieces detected by CBP were found in wood that bore the ISPM#15 stamp indicating that it had been treated. The proportion of infested shipments bearing the stamp has not changed over the past eight years. This is alarming and we need to understand the reason. Does this finding indicate widespread fraud? I understand that most inspectors believe this is the cause. Other possible explanations are accidental misapplication of the treatments or the treatments simply not working as expected. APHIS researchers have found that larvae from wood subjected to methyl bromide fumigation were more likely to survive to adulthood than those intercepted in wood that had been heat treated (Nadel et al. 2016). Does this indicate that methyl bromide fumigation is less effective? What effort is APHIS making to determine which of these explanations is correct?
Certain countries have a long-standing record of non-compliance with ISPM#15. APHIS’ database of pest interceptions on wood packaging over the period Fiscal Year 2011 to FY 2016 contains 2,547 records of insect detections from dozens of countries. The countries of origin with the highest numbers of shipments detected to have pests present were Mexico, China, Italy, and Costa Rica. These numbers reflect in part the huge volumes of goods imported from both Mexico and China. But China and Italy stand out for their poor performance. (The U.S. does not regulate – or inspect! – wood packaging from Canada; see blog here.)
Meissner et al. say that as of a decade ago, Chinese shipments were only half as likely to be enclosed in wood packaging as are shipments from other exporters. Yet shipments from China still rank second in the number of non-compliant shipments; they make up 11% of all interceptions. In part, the data reflect inspection priorities: due to the great damage caused by Asian insects to North American trees and the past record of poor compliance, CBP targets shipments from China for more intense scrutiny. Still, the high number of detections reflects continuing non-compliance by Chinese exporters. And remember – the U.S. and Canada began requiring treatment of wood packaging from China at the end of 1998 – nearly 20 years ago! [Feb 17 blog]
We don’t import a lot of goods from Italy – but Italian shipments of decorative stone and tile have always been plagued by high levels of pests in accompanying wood packaging. Indeed, more pests have been found in wood supporting tiles and stone than any other type of commodity in 24 of the 25 years preceding 2014 (Haack et al. 2014).
What is APHIS doing to pressure these countries to improve their compliance? As I blogged in October, link the Bureau of Customs and Border Protection began imposing a financial penalty on first-time violators in November 2017. Since interception data do not provide an adequate measure of the pest approach rate (see Haack et al 2014 for an explanation), APHIS should commission an analysis of Agriculture Quarantine Inspection Monitoring data to determine the pest approach rate before and after the CBP action in order to determine whether the more aggressive enforcement has led to reductions in non-compliant shipments at the border.
What Can Be Done to Slow or Eliminate this Pathway?
I reiterate my call for holding foreign suppliers responsible for complying with ISPM#15. One approach is to penalize violators. Now that the Bureau of Customs and Border Protection has toughened its enforcement, the U.S. Department of Agriculture should drop its decade-old policy of allowing importers to accumulate five (detected) violations in a calendar year before applying the civil penalties authorized by the Plant Protection Act.
Another step APHIS should take would be to prohibit use of packaging made from solid wood (boards, 4 x 4s, etc.) by foreign suppliers which have a record of repeated violations over the 12 years that ISPM#15 has been in effect – or the 19 + years for exporters from Hong Kong & mainland China. Officials should allow continued imports from those same suppliers as long as they are contained in other types of packaging materials, including plastic, metals, fiberboards …
SOURCES
Aukema, J.E., D.G. McCullough, B. Von Holle, A.M. Liebhold, K. Britton, & S.J. Frankel. 2010. Historical Accumulation of Nonindigenous Forest Pests in the Continental United States. Bioscience. December 2010 / Vol. 60 No. 11
Haack, R. A., K. O. Britton, E. G. Brockerhoff, J. F. Cavey, L. J. Garrett, M. Kimberley, F. Lowenstein, A. Nuding, L. J. Olson, J. Turner, and K. N. Vasilaky. 2014. Effectiveness of the international phytosanitary standard ISPM no. 15 on reducing wood borer infestation rates in wood packaging material entering the United States. Plos One 9:e96611.
Hulme, P.E. 2009. Trade, transport and trouble: Managing invasive species pathways in an era of globalization. Journal of Applied Ecology 46:10-18
Jung, T. et al. 2015 “Widespread Phytophthora infestations in European nurseries put forest, semi-natural and horticultural ecosystems at high risk of Phytophthora disease” Forest Pathology. November 2015; available from Resource Gate
Klapwijk, M.J., A.J. M. Hopkins, L. Eriksson, M. Pettersson, M. Schroeder, A. Lindelo¨w, J. Ro¨nnberg, E.C.H. Keskitalo, M. Kenis. 2016. Reducing the risk of invasive forest pests and pathogens: Combining legislation, targeted management and public awareness. Ambio 2016, 45(Suppl. 2):S223–S234 DOI 10.1007/s13280-015-0748-3
Koch, F.H., D. Yemshanov, M. Colunga-Garcia, R.D. Magarey, W.D. Smith. 2011. Potential establishment of alien-invasive forest insect species in the United States: where and how many? Biol Invasions (2011) 13:969–985
Leung, B., M.R. Springborn, J.A. Turner, E.G. Brockerhoff. 2014. Pathway-level risk analysis: the net present value of an invasive species policy in the US. The Ecological Society of America. Frontiers of Ecology.org
Levinson, M. The Box: How the Shipping Container Made the World Smaller and the World Economy Bigger Princeton University Press 2008
Liebhold, A.M., E.G. Brockerhoff, L.J. Garrett, J.L. Parke, and K.O. Britton. 2012. Live Plant Imports: the Major Pathway for Forest Insect and Pathogen Invasions of the US. www.frontiersinecology.org
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. Caribbean Invasive Species Working Group (CISWG) and USDA APHIS Plant Epidemiology and Risk Analysis Laboratory
Meurisse, N. D. Rassaati, B.P. Hurley, E.G. Brockerhoff, R.A. Haack. 2018. Common Pathways by which NIS forest insects move internationally and domestically. Journal of Pest Science. https://doi.org/10.1007/s10340-018-0990-0
Nadel, H., S. Myers, J. Molongoski, Y. Wu, S. Linafelter, A. Ray, S. Krishnankutty, A. 2016. Identificantion of Port Interceptions in Wood Packaging Material Cumulative Progress Report, April 2012 – August 2016
Yemshanov, D., F.H. Koch, M. Ducey, K. Koehler. 2012. Trade-associated pathways of alien forest insect entries in Canada. Biol Invasions (2012) 14:797–812
Posted by Faith Campbell
We welcome comments that supplement or correct factual information, suggest new approaches, or promote thoughtful consideration. We post comments that disagree with us — but not those we judge to be not civil or inflammatory.
The number of new pathogens discovered each year on 131 focal host plant species in New Zealand (closed circles) and the mean annual rate of pathogen arrival estimated from the model (solid blue line), with shading showing the 95% credible interval.
Benjamin A. Sikes and several coauthors (article available here; open access!) find that targetted biosecurity programs can reduce the establishment of nonnative pathogens even while global trade and travel continue to increase.
The study relies on data from New Zealand because that country has more than 150 years of data on phytosanitary policies and pathogen introductions. Do other countries have data that would support a comparative study in order to test the authors’ conclusions more generally?
The study is unusual in analyzing introductions of a variety of forms of pathogens (fungi, oomycetes, and plasmodiophorids) rather than invertebrates. Pathogens pose significant plant health risks but are notoriously difficult to detect. The study used data on plant-pathogen associations recorded in New Zealand between 1847 and 2012. It focused on hosts in four primary production sectors: crops (46 species, including wheat, tomatoes, and onions); fruit trees (30 species, including grapes, apples, and kiwifruit); commercial forestry (42 species, including pines and eucalypts); and pastures (13 species of forage grasses and legumes). In total, 466 pathogen species for which the first New Zealand record was on one of these 131 host plants were included in the study. The pathogens were assumed to have arrived on imports seeds or fresh fruits of plants in the same family as the 131 hosts in the various production sectors.
After calculating each pathogen’s probable date of introduction, the authors compared those dates to contemporaneous levels of imports and incoming international travellers. Sikes et al. applied statistical techniques to adjust their data to the fact that detection of pathogens is particularly sensitive to variation in survey effort.
Findings:
The annual arrival rate of new fungal pathogens increased exponentially from 1880 to ~1980 in parallel with increasing import trade volumes. Subsequently rates stabilized despite continued rapid growth in not only imports but also in arrivals of international passengers.
However, there were significant differences among the four primary production sectors.
Arrival rates for pathogens associated with crops declined beginning in the 1970s but slightly earlier for those associated with pasture species. These declines occurred despite increasing import volumes.
Arrival rates of pathogens that attack forestry tree species continued to increase after 1960.
Arrival rates for pathogens that attack fruit tree species remained steady while import volumes rose steadily
Sikes et al. attribute these contrasting trends between production sectors to differences in New Zealand’s biosecurity efforts. They record when phytosanitary restrictions targetting the four sectors were adopted and link those changes to reductions in numbers of pathogens detected a decade or so later. They conclude that targetted biosecurity can slow pathogen arrival and establishment despite increasing trade and international movement of people.
Regarding the contrasting situation of the forestry and fruit tree sectors, Sikes et al. note that while phytosanitary inspections of timber imports was initiated in 1949, it focussed primarily on invertebrate pests. In addition, surveys for pathogens on fruit tree and forestry species were less robust than in the cases of crop and pasture species, and the peak survey effort occurred several decades later – in 1980 for fruit trees, 2000 for forestry species.
Furthermore, pathogens of forestry and fruit tree species can be introduced on types of imports other than seeds and fresh fruits, including soil and live plant material (e.g., rootstock) and untreated wood products.
Sikes et al. say there is no evidence of slowed pathogen arrival rates resulting from imposition of post-entry quarantine to live plant material beginning in the 1990s. I find this very troubling. Post-entry quarantine is a high-cost strategy. Still, several plant pathologists have advocated adoption of this strategy because they believed it would be sufficiently more effective in preventing introductions of – especially! – pathogens as to be worthwhile. Do others have data with which to add to our understanding of this disturbing phenomenon?
The authors suggest that introductions of tree-attacking pathogens on rising imports of wood packaging might have swamped decreases in introductions via other vectors. They consider that implementation of International Standard for Phytosanitary Measures (ISPM) No. 15 in 2002 means it is too early to see its impact in detection data. As I have blogged several times, implementation of ISPM#15 by the United States, at least, has reduced presence of detected pests – primarily insects – by 52%. Little is known about the presence of pathogens on wood packaging – according to some experts, inspectors rarely even look for pathogens. So I think the authors’ suggestion might not fully explain the continuing introduction of pathogens that attack tree species used in plantation forestry in New Zealand.
Prof. Michael Wingfield of South Africa has written numerous articles on the spread of pathogens that attack Eucalyptus on seeds imported to establish plantations in various countries; one such article is available here. This seems a more likely explanation to me.
The study’s analysis demonstrated that the overall rate of non-native fungal pathogen establishment in New Zealand was more strongly linked to changes in import trade volume than to changes in numbers of international passengers arriving on the islands. Although Sikes et al. don’t explicitly raise the question, they note that New Zealand has put considerable effort into screening incoming people – which appears from these data to have a smaller payoff than imposing phytosanitary controls on imports.
Recent declines in surveys mean the authors must estimate current pathogen arrival rates. The data gaps exacerbate the inevitable uncertainty associated with the time lag between when an introduction occurs and when it is detected. They estimate that an average of 5.9 new species of fungal pathogens per year have established on the focal host plant species since 2000. They estimate further that 55 species of pathogens are present in New Zealand but have not yet been detected there.
I am quite troubled by the reported decline in New Zealand’s postborder pathogen survey efforts since about 2000. This appears very unwise given that the risk of new introductions of pathogens that attack fruit and forestry trees continues – or even rises! Indeed, scientists associated with the forestry industry note the risk to Douglas-fir and Monterrey (Radiata) pine plantations from the pitch canker fungus Fusarium circinatum – which could be introduced on imported seeds, nursery stock, and even wood chips. Radiata pine makes up 92% of softwoods planted – and exotic softwoods constitute 97% of the plantation forestry industry.
Furthermore, non-native pathogens threaten New Zealand’s unique forest ecosystems. Since this study focused on non-native plant hosts, it does not address the risk to native forest species. However, the threat is real: Kauri trees – the dominant canopy species in some native forest types – is suffering from a dieback caused by an introduced Phythopthora. Also, two other pathogens threaten the many trees and shrubs in the Myrtaceae family found in New Zealand – Puccinia rust (which is established in Australia but not New Zealand) or the Ceratocystis fungi causing rapid ohia death – both threaten native forests in Hawai`i, as discussed in a recent blog.
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.
As I wrote in my blog in October, the Department of Homeland Security Bureau of Customs and Border Protection (CBP) has reversed a previous policy and now has the option to impose a financial penalty on importers when any of their shipments does not comply with the international standard for wood packaging (International Standard for Phytosanitary Measure Number 15 – or ISPM#15). The penalties are assessed under Custom’s authority per Title 19 United States Code (USC) § 1595a(b) or 19 USC § 1592.
The Department of Agriculture has its own legal authority to penalize shippers whose wood packaging violates regulations implementing ISPM#15. However, USDA not taken the equivalent step of using its own authority to crack down on violators. Why not?
APHIS’ legal authority stems from the Plant Protection Act of 2000 [7 U.S.C. §7701, et seq. (2000)] (The text is posted here)
This law provides broad authority to APHIS to penalize non-compliant importers, using both civil and criminal penalties. Under Section 7734 (b):
“Any person that violates this chapter … may, after notice and opportunity for a hearing on the record, be assessed a civil penalty by the Secretary…” The penalty can vary from $50,000 to $1 million, depending on whether the importer is an individual or a corporation; the number of violations adjudicated in the proceeding; the gravity of the violation; and the importer’s ability to pay. Civil penalties can be assessed regardless of whether the violation was intentional (in the language of the statute, “willful”).
Under Section 7734(a), the Department may seek criminal penalties in cases when the importer “knowingly” violated the law and its implementing regulations. Criminal penalties include both fines and imprisonment. To apply a criminal penalty, USDA must convict the importer in a trial – prove the violation beyond a reasonable doubt.
It is puzzling that USDA has not acted on this authority.
As we all know, the biological diversity of America’s forests’ is severely threatened by wood-borers that can enter the country in wood packaging. Tree mortality caused by non-native pests has been estimated to cost municipalities $1.7 billion per year (Aukema et al. 2011). For discussions of introduced pests’ impacts, see the sources listed at the end of this blog.
Nearly 12 years after APHIS adopted regulations implementing the formal International Standard for wood packaging, significant numbers of shipments that do not comply with the regulations continue to arrive. In the fiscal year that ended on September 30, Customs detected 2,000 shipments in which the wood packaging did not bear the mark certifying that the wood had been treated in accordance with ISPM#15. In nearly 900 additional shipments, CBP detected damaging pests in the wood packaging. (For more detail on this issue, see my blog from last February.) link. So, the need to improve compliance is manifest. Imposing a financial penalty strikes me as an available and useful strategy to achieve that improvement.
The new CBP policy is a much-needed step. Now USDA should reinforce that action by implementing its own enforcement powers. The USDA’s Office of General Counsel and APHIS should be asked what is preventing implementation and what can be done to move this forward. Effective action to interdict forest pests requires strong enforcement by both CBP and USDA. Right now, it looks like the Department of Homeland Security cares about U.S. forests more than the Department of Agriculture.
SOURCES
Aukema, J.E., B. Leung, K. Kovacs, C. Chivers, K. O. Britton, J. Englin, S.J. Frankel, R. G. Haight, T. P. Holmes, A. Liebhold, D.G. McCullough, B. Von Holle.. 2011. Economic Impacts of Non-Native Forest Insects in the Continental United States PLoS One September 2011 (Volume 6 Issue 9)
Lovett, G.M., M. Weiss, A.M. Liebhold, T.P. Holmes, B. Leung, K.F. Lambert, D.A. Orwig , F.T. Campbell, J. Rosenthal, D.G. McCullough, R. Wildova, M.P. Ayres, C.D. Canham, D.R. Foster, S.L. LaDeau, and T. Weldy. 2016. Nonnative forest insects and pathogens in the United States: Impacts and policy options. Ecological Applications, 0(0), 2016, pp. 1–19. DOI 10.1890/15-1176.1 Recommendations available at www.caryinstitute.org/tree-smart-trade
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.
On September 25, the DHS Bureau of Customs and Border Protection (CBP) announced that beginning on November 1, the agency would no longer eschew penalizing importers of non-compliant wood packaging until that importer had accumulated five such interceptions in the course of a year.
Beginning November 1, “responsible parties with a documented WPM violation may be issued a penalty under Title 19 United States Code (USC) § 1595a(b) or under 19 USC § 1592.”
As readers of this blog might remember, I have frequently fulminated against the “five strikes” policy. The United States began full implementation of the international standard governing treatment of wood packaging (ISPM#15) 11 and ½ years ago. The U.S. and Canada began requiring China to treat its wood packaging nearly 18 years ago. Nevertheless, numerous shipments containing wood packaging that does not comply with the regulations continue to arrive at our borders – and to bring pests. As of February, only about 30 import shipments (out of nearly 21,000 shipments found to be in violation of ISPM#15 requirements) have received a financial penalty.
shipments of stone or tile are frequently supported by non-compliant wood packaging; photo (c) the Queen by right of Canada (CFIA)
In a blog I posted in February I described the continuing detections of pests in wood packaging. In summary, during Fiscal Years 2010 through 2016, CBP detected nearly 5,000 shipments of wood packaging that harbored a pest in a regulated taxonomic group. The APHIS interception database for the period FYs 2011 – 2016 contained 2,547 records for insect detections on wood packaging. The insects belonged to more than 20 families. A quarter were in the Cerambycid family; 11% were Buprestids. In a study of insect larvae removed from incoming wood packaging from the period April 2012 through August 2016, APHIS scientists evaluated 1,068 insects from 786 separate interceptions of non-compliant wood packaging. The wood packaging in all three datasets came from dozens of countries.
(Remember, the U.S. and Canada do not apply ISPM#15 to wood packaging moving between the two countries. Neither country inspects wood packaging from the other country at even the low rate of inspection applied to wood packaging coming from other countries – so we don’t know how many quarantine pests are moving in this high-volume trade.)
The Bureau of Customs’ action has partially fulfilled one of two recommendations that I made in the February blog. I applaud CBP’s action. However, neither CBP or APHIS has yet prohibited importers with records of repeat violations from using wood packaging – my second recommendation.
Note that the CBP decision applies Customs regulations; USDA has apparently not changed its policy of allowing importers to accumulate five (detected) violations in a calendar year before applying the civil penalties provided by the Plant Protection Act. Why?
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.
You know that the continuing pest risk associated with imports of wood packaging is among my biggest concerns. See, for example, fact sheets here and blogs here and here.
A new book about the family Cerambycidae (edited by Wang 2017; reference at end of blog) confirms that longhorned beetles continue to be introduced to many countries via this pathway, more than a decade after widespread implementation of the international standard governing wood packaging (ISPM#15). Furthermore, data from several countries confirm that China continues to fall short … but that problems are more widespread.
The Wang book finds that 16 outbreaks of the Asian longhorned beetle (ALB) were detected between 2012 and 2015.
Unless otherwise noted, the information provided here comes largely from the book’s chapter on biosecurity coauthored by Dominic Eyre and Robert A. Haack (see link below). Opinions stated are mine, unless specified otherwise.
In some cases – which I will note – further details are from my earlier posts.
While I think the risk of introduction of highly damaging pests via the wood packaging pathway is well documented in Wang (2017) and other publications, no one can truly quantify this risk because of shortcomings in countries’ data. Available data come primarily from countries’ records of pest “interceptions” – usually at points of entry. However, interception data are inadequate to conclusively establish the lack of a threat for a particular trade or to provide a fair comparison of the relative threat of particular trades. Most interception databases have the following shortcomings (Eyre and Haack are summarizing points made by a third scientist – Lee Humble – in an earlier article):
(1) interception databases are not based on random sampling, which is necessary to measure the “approach” or “infestation” rate;
(2) inspections which find no pests are not recorded, so we cannot know what proportion of incoming shipments are infested;
(3) once inspectors have discovered a quarantine pest in a shipment, the consignments may be destroyed without further inspection, and thus other exotic organisms can be missed;
(4) only a small percentage of individual shipments are inspected; and
(5) organisms often are not identified to species due to difficulty of identifying larvae.
Furthermore,
(1) trade volumes and sources can change rapidly;
(2) the number of consignments inspected varies from year to year in response to national and regional plant health and wider government priorities;
(3) the method and intensity of quarantine inspections can vary within and among countries and as well as over time; and
(4) different proportions of consignments from different trades can be inspected, reflecting the perceived quarantine risks of each trade.
Still, scientists try to analyze the available data because propagule pressure may be the most important factor in determining whether an exotic pest becomes established.
What have they found?
Data from both the United States and Europe document that problems of non-compliance continue in recent years – more than a decade after adoption of ISPM#15.
United States:
Since APHIS interception records began being computerized in 1985, Cerambycidae have been among the most frequently intercepted insect families associated with wood products and packaging. The top five countries for infested shipments during the period 1984 – 2008 were China, Italy, Mexico, Turkey and Spain. A country’s rank is linked in part to import volumes – which are very high for China, Canada, and Mexico. Because the U.S. inspects very limited quantities of wood packaging from Canada, its absence from the top five may be misleading [discussed in my blog from February, here.
Another factor explaining these countries’ rankings is the continued – in fact increasing! – presence of pests in wood packaging accompanying imports of tile and quarry products (e.g., marble, slate). Many of these imports are from Italy, Spain, and Mexico. Interceptions on these imports increased significantly from the mid-1990s to 2008. The increase in these interceptions is most alarming because it shows USDA leaders have not yet taken effective action to curtail this risk, despite its being evident since record-keeping began.
Over the period Fiscal Years 2010 through 2016, the U.S. Bureau of Customs and Border Protection has detected nearly 5,000 consignments in which cases the wood packaging harbored a pest in a regulated taxonomic group. APHIS experts identified 2,500 insects taken from wood packaging during this period; a quarter were Cerambycids. A second APHIS analysis of a subset of the wood packaging-associated insects found examples from 39 countries, including 212 shipments from Europe; 130 shipments from Asia; and 341 shipments from the Americas – almost exclusively Mexico. [These detections are discussed in my blog from February, here.
Europe has had a similar experience.
Interception records included in EUROPHYT show 306 Cerambycidae interceptions on wood packaging over the period 1998 – 2013. The number of interceptions recorded in 2012 and 2013 are double those of all previous years. Each year, the majority are on wood packaging from China.
Most interceptions of ALB (distinct from detections of establishments) have occurred after the shipment cleared border inspection procedures, e.g., in warehouses.
As with the U.S., while the majority of non-compliant shipments are from China, the problem is worldwide: Europe has also found various species of longhorned beetles in wood packaging from various European countries (inside and outside the European Union), other Asian countries, Africa, Australasia, and the Americas.
Austria inspected 451 consignments of stone imports received April 1, 2013 – April 14, 2014. Forty-four consignments (9.8%) were found to be out of compliance with ISPM#15. Live Cerambycidae were found in 38 consignments (8%), including ALB. This finding confirms the widespread awareness that stone imports rank high for non-compliant wood packaging.
Since March 31, 2013, the European Union has required inspection of 90% of consignments of slate, marble, and granite and 15% of consignments of two other categories of stone imports.
CBP agriculture specialists in Laredo, Texas, examine a wooden pallet for signs of insect infestation. [Note presence of an apparent ISPM stamp on the side of the pallet] Photo by Rick PauzaUnited States
As noted by Haack et al. (2014) (reference below), as of 2009, approximately 13,000 containers harboring pests probably enter the U.S. each year. That is 35 potential pest arrivals each day. [This issue is also discussed in the fact sheet and blogs here and here.
The United States has not specified an obligatory inspection rate for such high-risk imports as stone and tile. Instead, it relies on Customs and Border Protection to target import shipments suspected of being out of compliance based on past performance of importers, suppliers, and types of imports.
Several relevant issues are discussed in the blog in February 2017 (second blog linked to above). First, I noted that the U.S. Department of Homeland Security Bureau of Customs and Border Protection – over the seven-year period Fiscal Years 2010 through 2016 – has detected nearly 5,000 cases of wood packaging harboring a pest in a regulated taxonomic group. Comparing the estimate by Haack et al. 2014 with the CBP data indicates that Customs is detecting about 6% of all pest-infested shipments.
Furthermore, about 26% of infested wood pieces detected by CBP were found in wood that was marked as having been treated according to ISPM#15 requirements. What does this mean? Fraud? Accidental misapplication of the treatments? Or are the treatments less effective than hoped? What are USDA and other responsible agencies doing to clarify the causes?
CBP staff reported that only about 30 import shipments (out of nearly 21,000 shipments found to be in violation of ISPM#15 requirements) have received a financial penalty. How can USDA and Customs officials justify this failure to enforce the regulations?
What Can Be Done to Close Down the Wood Packaging Pathway
I suggest that our goal should be to hold foreign suppliers responsible for complying with ISPM#15. One approach is to penalize violators. APHIS and Customs might
Prohibit imports in packaging made from solid wood (boards, 4 x 4s, etc.) from foreign suppliers which have a record of repeated violations over the 11 years ISPM#15 has been in effect (17 years for exporters from Hong Kong & mainland China). Officials should allow continued imports from those same suppliers as long as they are contained in other types of packaging materials, including plastic, metals, or fiberboards.
Fine an importer for each new shipment found to be out of compliance with ISPM#15 in cases when the foreign supplier of that shipment has a record of repeated violations.
There would need to be a severe penalty to deter foreign suppliers from simply changing their names or taking other steps to escape being associated with their violation record.
At the same time, the agencies should work with non-governmental organizations and importers to promote creation of an industry certification program that would recognize and reward importers who have voluntarily undertaken actions aimed at voluntarily exceeding ISPM#15 requirements so as to provide a higher level of protection against invasive species that would otherwise potentially be introduced into the United States.
What You Can Do
Tell your member of Congress and Senators that you are worried that our trees are still being put at risk by insects arriving in wood packaging. Ask them to urge the USDA Secretary Sonny Perdue to take the actions outlined above in order to curtail introductions of additional tree-killing pests.
Talk to your friends and neighbors about the threat to our trees. Ask them to join you in communicating these concerns to their Congressional representatives and Senators.
Write letters to the editors of your local newspaper or TV news station.
Use your knowledge about pests threatening trees in your state or locality in your communications!
Other Introduction Pathways for Cerambycids
tree removals in Tukwilla, WA to eradicate citrus longhorned beetle; photo by Washington State Department of Agriculture
Plants for planting
Other studies have confirmed that importation of living plants (called by regulators “plants for planting”) is a high-risk pathway for introducing tree-killing pests. See the Eyre and Haack chapter for a summary.
This is as true for highly damaging Cerambycids as for other types of plant pests. One of the most damaging is the citrus longhorned beetle (CLB) (Anoplophora chinensis). CLB [https://www.dontmovefirewood.org/invasive-species/] poses an even greater threat to North American forests than ALB – it has a wider host range and climate-matching models show that it could establish across most of the United States. CLB were detected in a nursery in Tukwilla, Washington, in 2001; the pest was eradicated. Nine CLB outbreaks have been detected in Europe; three are considered eradicated (Eyre & Haack 2017).
Eyre and Haack (2017) report that in Europe of the 455 Cerambycidae intercepted over the period 1998 – 2013, 54 were on imported in living plants. These included probably 49 citrus longhorned beetle (CLB). Most were detected primarily on maple nursery stock that originated China (32), with smaller numbers from other countries, including Netherlands (8), and Italy (where CLB has been established).
New Zealand has intercepted 74 CLB on plants for planting over the 28 year period 1980 – 2008. One third of this total was intercepted in 2008.
Authorities’ Responses (or lack thereof)
Europe
Since 2012, the European Union has required that 10% of CLB host plants imported into the European Union should be destructively sampled (that is, dissected to see whether insects are present internally).
This requirement supplements a broader requirement that plants for planting be treated as a high risk commodity. Member states are required to inspect all incoming P4P consignments. This requirement is, however, undermined by much more lenient requirements regarding movement of plants among EU member states – some genera are not regulated … others are controlled by Plant Passports – an industry-led scheme. [For more on this issue, see my blog from October 2016 here.
United States
APHIS issued a Federal order tightly restricting imports of CLB hosts from Europe in 2013 – four years after a CLB outbreak was detected in a part of the Netherlands which is a center for the production of hardy ornamental nursery stock for European and probably American markets.
APHIS proposed to revise its overall plant importation regulations (the “Q-37 regulations) to rely more on integrated management by the exporting nurseries in contrast to port inspections. This rulemaking has stalled. [See my blog about this here.]
Finished Wood Products
While no country is keeping comprehensive records, finished wood products have transported longhorned beetles. Eyre and Haack (2017) concluded that upholstered furniture presents one of the highest risk among the finished wood products – partly because imports are rising rapidly, partly because insect-damaged wood can be hidden under the upholstery. New Zealand found that some Asian manufacturers place good quality wood on visible surfaces and poor quality timber (insect damaged and bark covered) in internal sections. Officials inspected 49 couches and found that 30 had wood with bark, 19 had insect contaminants, and 32 had visible insect damage. Fungal samples were isolated from 11 of the couches. They found 4 longhorned beetles.
References
Wang, Q. (Ed.). 2017. Cerambycidae of the world: biology and pest management. Boca Raton, FL: CRC Press
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.
Numbers of non-native pests in counties of the 49 continental states; Map prepared by Andrew Liebhold, USFS in 2014. More recent introductions are not represented; nor are insects native to some part of North America
Currently, the Northeast and Midwest have the highest number of non-native, tree-killing insect and pathogen species (see map above). However, Pacific coast states have two-thirds the numbers of pest species of the Northeast – and are catching up. Two articles modeling the likelihood of new pest introductions point to the particular vulnerability of the Pacific Coast states – especially California – to pest introductions from Asia.
Koch et al. 2011 (see reference at the end of the blog) utilized various sources of information about volumes of imports likely to be associated with wood-boring pests — stone; raw wood and wood products (including crates & pallets); metals; non-metallic minerals; auto parts; etc. From this, the authors estimated both a nationwide establishment rate of wood-boring forest insect species and the likelihood that such insects might establish at more than 3,000 urban areas in the contiguous U.S. While their estimate was based on 2010 imports, they also projected rates for 2020.
See my blog from March 10 for various scientists’ estimates of the overall, nationwide rate of introduction. Koch et al. estimated the nation-wide introduction rate at between 0.6 and 1.89 forest insects and pathogen species per year for the period 2001–2010 and 0.36 and 1.7 species per year for 2011–2020. In other words, we should expect a new alien forest insect species to become established somewhere in the United States every 2–3 years. If one-tenth of these new introductions turn out to cause significant damage, then we can expect a “significant” new forest pest every 5–6 years.
Pacific coast states – especially California – are at highest risk.
Koch et al. evaluated the introduction risk for 3,126 urban areas across the country. The metropolitan area with the highest risk is Los Angeles–Long Beach–Santa Ana, California. For both 2010 and 2020, the predicted rates for a new pest establishing there is every 4–5 years.
Looking ahead to 2020, the situation worsens for three California metro areas – Los Angeles–Long Beach–Santa Ana; San Diego; and Riverside-San Bernardino. At San Francisco-Oakland, the predicted establishment rates remain steady. Most of the rest of the top 25 urban areas show decreases in establishment rate between 2010 and 2020.
This rising risk to California urban areas is driven by the growth of imports from Asia. For the four California urban areas, the establishment rate of Asian species is projected to increase 6–8% between 2010 and 2020. The Los Angeles–Long Beach–Santa Ana area could potentially expect the establishment of an alien forest insect species originating specifically from Asia alone (not the entire world) every 4–5 years.
[The polyphagous and Kuroshio shot hole borers are examples of recently introduced pests from Asia. Both are described, inter alia, here; a distribution map for PSHB is available here.]
Koch et al. note that the Los Angeles metropolitan area has a dense human population with corresponding high demand for goods and materials, so a substantial proportion of imports clearing the port remains in the areas. Furthermore, widespread planting of non-native plants provides a range of potential hosts that can support invaders that would not otherwise become successfully established.
A second source also indicates a heightened risk to Pacific Coast states. Yemshanof et al. used similar modeling techniques to evaluate the risk of tree pest introductions to Canada … and to the U.S. in the form of transshipped goods. (See my earlier blog.)
The Yemshanof et al. model showed that 8% of all forest pests introduced to the U.S. on imported wood or wood packaging — as estimated by Koch et al. — would come through goods transshipped through Canada. The risk is highest to the Pacific Coast states since they are the most likely to receive Asian goods transiting through Canada.
Note that the phytosanitary agencies in both the U.S. and Canada proposed in 2010 that wood packaging originating in one of the countries and shipped to the other be required to meet the international regulations under ISPM#15. However, APHIS was unable to adopt this regulation under the Obama Administration, and such an action seems even less likely under the Trump Administration. Canada is unlikely to adopt the new rules without a coordinated U.S. action.
Southern California also imports lots of plants – another pathway for pest introductions.
Koch et al. suggest that authorities use these models to prioritize border control efforts (e.g., commodity inspections), post-border surveillance, and rapid-response measures. I see some problems with these suggestions. First, enhanced commodity inspections are not likely to measurably diminish the risk of introduction to the region. Second, rapid-response measures require both increased funds – which are expected to decrease; and political will. I have blogged several times about California’s decisions to not implement official, regulatory responses to recently detected pests.
Instead, people in the region should actively build alliances and press their regional political leaders – governors, mayors, senators, members of Congress – to demand that the U.S. Department of Agriculture and the Congress adopt policies that will strengthen protection for the region’s trees.
New pest detected in California!
California authorities have detected a new woodboring beetle – the olive wood borer (Phloeotribus scarabaeoides). It was detected in an olive tree in a grape vineyard in Riverside County. This is the first detection of the species in the Western Hemisphere. Known or suspected hosts include several trees in the olive family (Oleaceae), including olive trees, privet, ash, and common lilac; as well as oleander (Apocynaceae).
Since this new pest is native to the Mediterranean region, it does not appear to be an example of the risk to California from Asia … The source (Diagnostic Network News; see below) does not speculate on the pathway by which the introduction occurred.
What Can We Do?
Ask your state’s Governor to
Communicate to the USDA Secretary the need to amend policies & regulations
(Coordinate this effort with governors of other states.)
Put forest pest issue on the agenda of National Governors’ Association
Ask your state’s Congressional delegation to pressure USDA Secretary to amend policies and regulations
Communicate concern about these pests to the media — and propose solutions.
Ask your state’s agricultural and forestry agency heads to
Ask their national associations to support proposals to USDA Secretary & Congress. These associations include
National Association of State Departments of Agriculture (NASDA)
National Association of State Foresters (NASF) or its Western regional group, the Council of Western State Foresters
Communicate to the media both the agency’s concern about tree pest threats and proposed solutions.
We can also act directly.
Ask mayors and officials of affected towns and counties to
Push proposals at regional or National Conference of Mayors or National Association of Counties
Instruct local forestry staff to seek support of local citizen tree care associations, regional and national associations of arborists, Arbor Day & “Tree City” organizations, Sustainable Urban Forest Coalition, etc.
Reach out to local media with a message that includes descriptions of policy actions intended to protect trees — not just damage caused by the pests
Ask stakeholder organizations of which you are a member to speak up on the issue and support proposed solutions; e.g.,
Professional/scientific associations
Wood products industry
Forest landowners
Environmental NGOs
Urban tree advocacy & support organizations
Encourage like-minded colleagues in other states to press the agenda with their state & federal political players, agencies, & media.
Communicate to the media both your concern about tree pest threats and proposed solutions.
What Specific Actions Should We Suggest be Taken?
I suggest a coordinated package. However, you might feel more comfortable selecting a few to address each time you communicate with a policymaker. Choose those on which you have the most expertise; or that you think will have the greatest impact.
Make specific proposals, not vague ideas (see below for suggestions)
Always include information about how the pests arrive/spread (pathways such as imports of crates & pallets, or woody plants for ornamental horticulture) and what we can do to clean up those pathways (Don’t just describe the “freak of the week”)
Always point out that the burden of pest-related losses and costs falls on ordinary people and their communities. (Aukema et al. 2011 provides backup for this at the national level; try to get information about your state or city.)
We need to restore a sense of crisis to prompt action – but not leave people feeling helpless! We need also to bolster understanding that we have been and can again be successful in combatting tree pests.
Specific actions that will reduce risk that pests pose to our trees:
Importers switch from packaging made from solid wood (e.g., boards and 4”x4”s) to packaging made from other materials, e.g., particle boards, plastic, metal …
Persuade APHIS to initiate a rulemaking to require importers to make the shift. This can be done – although international trade agreements require preparation of a risk assessment that justifies the action because it addresses an identified risk (see my earlier blogs about wood packaging).
Create voluntary certification programs and persuade major importers to join them. One option is to incorporate non-wood packaging into the Department of Homeland Security Bureau of Customs and Border Protection’s (CBP) existing Customs-Trade Partnership Against terrorism (C-TPAT) program.
Tighten enforcement by penalizing shipments in packaging that does not comply with the current regulations
Persuade CBP and/or USDA to end current policy under which no financial penalty is imposed until a specific importer has been caught five times in a single year with non-compliant wood packaging. APHIS has plenty of authority to penalize violators under the Plant Protection Act [U.S.C. §7734 (b) (1)].
Restrict imports of woody plants that are more likely to transport pests that threaten our trees
In 2011, APHIS adopted regulations giving it the power to temporarily prohibit importation of designated high-risk plants until the agency has carried out a risk assessment and implemented stronger phytosanitary measures to address those risks. Plants deserving such additional scrutiny can be declared “not authorized for importation pending pest risk assessment,” or “NAPPRA”. A list of plants posing a heightened risk was proposed nearly 4 years ago, but it has not been finalized – so imports continue. APHIS should revive the NAPPRA process and utilize prompt listing of plants under this authority to minimize the risk that new pests will be introduced.
APHIS should finalize amendments to the “Q-37” regulation (proposed nearly 4 years ago) that would establish APHIS’ authority to require foreign suppliers to implement integrated programs to minimize pest risk. Once this regulation is finalized, APHIS could begin negotiating agreements with individual countries to adopt systems intended to ensure pest-free status of those plant types, species, and origins currently considered to pose a medium to high risk.
Strengthen early detection/rapid response programs by
Providing adequate funds to federal & state detection and rapid response programs. The funds must be available for the length of the eradication program – often a decade or more.
Engage tree professionals & citizen scientists more effectively in surveillance programs.
SOURCES
Koch, F.H., D. Yemshanov, M. Colunga-Garcia, R.D. Magarey, W.D. Smith. Potential establishment of alien-invasive forest insect species in the United States: where and how many? Biol Invasions (2011) 13:969–985
Western Plant Diagnostic Network First Detector News. Winter 2017. Volume 10, Number 1.
Yemshanov, D., F.H. Koch, M. Ducey, K. Koehler. 2012. Trade-associated pathways of alien forest insect entries in Canada. Biol Invasions (2012) 14:797–812
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.
CBP inspecting wood packaging; CBP photo
shipment of decorative stone with wood packaging
