invasive species policy – Page 17 – Center for Invasive Species Prevention

Congressional Funding for Key USDA Programs

Fiscal Year 2020 began on October 1, 2019. In December Congress adopted funding bills (appropriations) for the full fiscal year – which ends next September.

APHIS

In its Agriculture Appropriations bill, Congress is holding steady or increasing funding for several APHIS programs that are important for addressing tree-killing pests:

tree and wood pests program – $60 million (this is the same as FY2019, and $4 million above the Administration’s request);
Pest Detection – $27.4 million (this is same as FY219 and as the Administration’s request);
Methods development – $20.686 million (about the same as in FY2019 and the Administration’s request).
Specialty crops program – increased to $192.013 million. The accompanying report mentions two specific organisms as priorities – navel orangeworm and sudden oak death (apparently in response to an Oregon economic study and because Sen. Merkley is on the Appropriations Committee). This was above the $186 million in both the House and Senate bills and considerably above the Administration’s request of $176 million.

The Agriculture Appropriations bill reiterates helpful language from past laws authorizing the Secretary of Agriculture “to transfer … funds available to … the Department [of Agriculture] such sums as may be deemed necessary” to respond to disease or pest emergencies that threaten any segment of the U.S. agricultural production industry. However, for the past decade the Office of Management and Budget has prevented frequent use of this power. APHIS did receive emergency funds to address the spotted lanternfly in February 2018 (APHIS Press Release No. 0031.18)

(You might remember that in 2017-2018 I put forward amendments to the Farm Bill that would have broadened APHIS’ access to emergency funds. I sought especially to ensure that efforts to protect native vegetation and urban trees would be eligible for funding. Unfortunately, this amendment was not enacted.)

USDA Forest Service

The overall Research and Development program is funded at $305 million – a few million above what I advocated for. Of this total, $77 million is allocated to the Forest Inventory and Analysis program. In the past, research on invasive species has received about 10% of the total research funds. The USFS has been directed by Congress to restructure its research program. I will monitor any changes and determine the implications for invasive species concerns.

USFS engagement on pest issues with other federal agencies and state, local government, and private land managers is carried out through the Forest Health Management program under the State and Private Forestry division. While neither the appropriations legislation nor the accompanying report provides any direction on forest health activities, program staff report that funding for the overall program totals $104 million – about $6 million more than in FY2019. Program work on federal lands is funded at $66 million. However, $3 million has been deducted as part of a budget reform. After the deduction, this allocation is about $7 million above the funding level for FY 2019. Program work on non-federal “cooperative” lands is funded at $44 million. Congress has instructed that $2 million of this total be given to the eastern states’ forest health monitoring cooperative. The total “cooperative” lands allocation is $2 million above the FY2019 allocation.

Conclusion

I am very pleased by Congress maintaining or increasing funds for APHIS’ forestry programs. I am somewhat concerned by the pressure to reform USFS programs. I worry especially about the increasing focus on managing pests on federal lands compared to non-federal lands because nearly all damaging invasions begin on non-federal lands.

ash tree killed by emerald ash borer
Ann Arbor, MI
photo provided courtesy of former mayor John Hieftje

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.

Hawaiian Dry Forests – Glimmer of Hope for one tree, Alarm for a shrub

wiliwili flower
photo by Forrest and Kim Starr, courtesy of creative commons

Hawaii’s dryland forest is a highly endangered ecosystem. More than 90% of dry forests are already lost due to habitat destruction and the spread of invasive plant and animal species. However, a new publication documents some recovery of wiliwili trees from one major pest. At the same time, a new pest is spreading and killing naio, a critical dryland shrub. Both pests originated in countries that have rarely if ever been a source of U.S. pests. This is worrying because phytosanitary agencies have their hands full with imports from the usual sources. The role of California as a source of invasive species in Hawai`i has long deserved federal attention – but as far as I know has not received it.

Hope for Wiliwili Trees

The Hawaiian endemic wiliwili tree, Erythrina sandwicensis, occurs in lowland dry forests on all the major islands from sea level to 600 m. Wililwili is a dominant overstory tree in these habitats. (Unless otherwise noted, the principal source is Kaufman et al. in press – full citation at end of blog.)

The tree has been severely affected by the introduced Erythrina gall wasp, Quadrastichus erythrinae (EGW). The gall wasp was detected on Oahu in 2005 and quickly spread to the other Hawaiian islands.

Arrival of the EGW on Oahu was part of the insect’s rapid global range expansion. Originally from East Africa, it was first detected in the Mascarene Islands and Singapore in 2003. At the time, it was unknown to science. Within a few years it had spread across Asia, many Pacific islands (including Hawai`i), and to the Americas, including Florida in 2006, Brazil in 2014 (Culik 2014), and Mexico in 2017 (Palacios-Torres 2017). Although apparently restricted to the Erythrina genus as host, it has lots of opportunities. This genus has 116 species distributed across tropical and subtropical regions: 72 species in the Americas, 31 in Africa, and 12 in Asia.

The severe damage to wiliwili (and to non-native Erythrina trees planted in urban areas and as windbreaks) prompted Hawaiian officials to immediately initiate efforts to find a classical biological control agent. The process moved rapidly. A candidate – a parasitic wasp species new to science, Eurytoma erythrinae – was found in East Africa in 2006. Host specificity testing was carried out. Scientists quickly learned to rear the parasitic wasp in laboratories. Release of the biocontrol agent was approved in November 2008 – only three and a half years after the EGW was detected on Oahu.

The biocontrol agent’s impact was quickly apparent. Establishment was confirmed within 1–4 months at all release locations throughout Hawai`i. Reduced pest impacts to trees were detected within two years. By 2018, only 33% of the foliage was damaged on the majority of wiliwili trees. Damage to non-native Erythrina had also declined.

Results of Biocontrol Agent’s Release

The biocontrol agent’s efficacy in reducing EGW’s impacts on trees has been evaluated for 10 years after the agent’s release. Monitoring was conducted at sites on four of the six main islands. (The monitoring program and its findings are described in Kaufman et al. in press).

I wonder how many other biocontrol agents have been monitored so closely for such a long time? Shouldn’t they all be?

Given the uniqueness and importance of such long-term assessment, it is worth looking at the data in detail.

1) Foliar Damage and Tree Health

In 2008, before release of the biocontrol agent, more than 70% of young shoots in wiliwili trees that were inspected were severely infested. The damage rating of “severe” fell from about 80% of trees in 2008 to about 40% in 2011. About 20% of trees surveyed – at sites on all islands – had no gall damage.

By three years after release of the biocontrol agent (2011), mortality rates attributed to stress from the EGW infestation for trees in natural areas fell to 21%. Mortality rates for trees in botanical gardens was somewhat higher – 34%. Kaufman et al. proposed several possible reasons: a) lingering presence of systemic insecticides that might have harmed the biocontrol agents early in the releases; b) year-round sustenance for the EGW as a result of the i) presence of alternative hosts and ii) supplemental irrigation which maintained fresh foliage on the trees.

Less intensive monitoring occurred during 2013 – 2018. It showed continuing substantial suppression of EGW damage on Erythrina foliage, although levels varied among locations. Sites with the lowest precipitation and higher temperatures throughout the year had the slowest recovery of wiliwili. Still, trees are now producing vegetative flushes and healthier canopies during non-dormant periods.

2) Flower and Seed Damage

Successful reduction of infestations in flowers and seedpods was less immediate. Still, by 2011, seed-set had increased from less than 3% of trees setting and maturing seed, to almost 30% with mature seed. The proportion of trees bearing inflorescences also increased, with more than 60% of trees blooming three years after introduction of the biocontrol agent. There was also a slow but steady increase in seed production.

However, in 2019, it remains unclear how infestation of seedpods will affect germination and therefore future plant recruitment.

More worrying, little recruitment was observed over the 10 years. Hawaiian authorities have completed tests on, and are preparing a petition for release of, a second biocontrol agent, Aprostocitus nites. It is hoped that it will further suppress EGW in flowers and seedpods.

Still, poor recruitment is likely due to the combined impacts of multiple invasive species in native environments. A significant factor is a second insect pest – a bruchid, Specularius impressithorax – which can cause loss of more than 75% of the seed crop. I hope authorities are seeking methods to reduce this insect’s impacts.

The Hawaiian species group of the IUCN has given the wiliwili tree the Reed Book designation of “vulnerable”.

Worries for Naio

naio in bloom
photo by Forrest and Kim Starr, courtesy of creative commons

Naio (Myoporum sandwicense)is an integral component of native Hawaiian ecosystems, especially in dry forests, lowlands, and upland shrublands. However, it is also found in mesic and wet forest habitats. Naio is found on all of the main Hawaiian Islands at elevations ranging from sea level to 3000 m. The loss of this species would be not only a significant loss of native biological diversity but also a structural loss to native forest habitats.

The invasive non-native Myoporum thrips, Klambothrips myopori, was detected on the Big Island (Hawai‘i Island) in 2009 – four years after it was first detected on ornamental Myoporum species in California. At the time of the California detection, the species was unknown to science. It is now known that this species is native to Tasmania.

The thrips feeds on and causes galls on plants’ terminal growth and can eventually lead to death of the plant.

For close to a decade, the Myoporum thrips was restricted to the Big Island. It has now been found on Oahu (Wright pers. comm.) Alarmed by the high mortality of plants in California, in September 2010, the Hawaii Department of Lands and Natural Resources Division of Forestry and Wildlife and the University of Hawai‘i initiated efforts to determine spatial distribution, infestation rates, and overall tree health of naio populations on the Big Island. Monitoring took place at nine protected natural habitats for four years. This monitoring program was supported by the USFS Forest Health Protection program. (See also the chapter on naio by Kaufman et al. 2019 in Potter et al. 2019 – full citation at the end of this blog.)

naio damaged by thrips
photo by Leyla Kaufman, University of Hawaii

The monitoring confirmed that the myoporum thrips has spread and colonized natural habitats on the leeward side of Hawai`i Island. Infestation rates increased considerably at all sites over the duration of the four-year sampling period. Trees experiencing high infestation levels also showed branch dieback.

Medium-elevation sites (between 500–999 m) had the highest infestations and dieback: over 70% of the shoots had the worst damage.. At two sites, over 70% of the monitored trees have died.

Even though flowers and fruits were still seen at all sites, little to no plant recruitment was observed at these sites. Thus another plant species important in this endangered plant community is in decline.

Few management strategies are available for this pest. They include preventing spread to other islands and early detection followed by rapid application of pesticides.

Implications and Conclusions

The Erythrina gall wasp and myoporum thrips are only two of the thousands of invasive species established in Hawai`i. Island ecosystems, especially Hawai`i, are well recognized as especially vulnerable to invasive species. It has been estimated that on average 20 new arthropod species become established in Hawai`i every year.

East Africa and Tasmania are new sources for invasive species. Phytosanitary agencies need to adjust their targetting of high-risk imports to recognize this reality. Regarding the Hawaiian introduction of the thrips, there was probably made an intermediary stop in California – which is not unusual. (See also ohia rust.)

I applaud Hawaiian officials’ quick action to counter these pests. I wish their counterparts in other states did the same.

There are multiple threats to Hawaii’s dry forests, including habitat modification and fragmentation; wild fires; seed predation by rodents; predation on seeds, seedling, and saplings by introduced ungulates (e.g. feral goats, pigs and deer); competition with invasive weeds; and damage by invasive insect pests and diseases.

With so much of Hawaii’s dry forests already lost, the release of biocontrol agents targetting specific pests is only one element of a much-needed effort. Long-term protection of wiliwili and naio depends on greater efforts to reduce all threats and to stimulate natural regeneration of this ecosystem. These programs could include predator-proof fencing to keep out ungulates; baiting rodents and snails; and active collection. Breeding, and planting of threatened plant species in an effort to protect both the individual species and the habitat.

SOURCES

Culik, M.P., D. dos Santos Martins, J. Aires Ventura & V. Antonio Costa. The invasive gall wasp Quadrastichus erythrinae (Hymenoptera: Eulophidae) in South America: is classical biological control needed?

Kaufman, L.V., J. Yalemar, M.G. Wright. In press. Classical biological control of the erythrina gall wasp, Quadrastichus erythrinae, in Hawaii.: Conserving an endangered habitat. Biological Control. Vol. 142, March 2020

Palacios-Torres, R.E., J. Malpica-Pita, A.G. Bustamante-Ortiz, J. Valdez-Carrasco, A. Santos-Chávez, R. Vega-Muñoz and H. Vibrans-Lindemann. 2017. The Invasive Gall Wasp Quadrastichus erythrinae Kim in Mexico. Southwestern Entomologist.

Potter, K.M. B.L. Conkling. 2019. Forest Health Monitoring: National Status, Trends, and Analysis 2018. Forest Service Research & Development Southern Research Station General Technical Report SRS-239

Kaufman, L.V, E. Parsons, D. Zarders, C. King, and R. Hauff. 2019. CHAPTER 9. Monitoring Myoporum thrips, Klambothrips myopori (Thysanoptera: Phlaeothripidae), in Hawaii

Wright, Mark. 2005. Assistant Professor and Extension Specialist, University of Hawaii. Personal communication.

Will Chaos Replace International Trade Rules?

The United Nations has designated 2020 as the International Year of Plant Health. I welcome the possibility of heightened awareness – although it could result in promises that are more optimistic than facts warrant.

APHIS and probably other national and international phytosanitary bodies have planned events to draw attention to the importance protecting of plant health. For example, the APHIS website lists numerous meetings, some of which are special events, e.g., Safeguarding 2020: North American Safeguarding and Safe Trade Conference in Washington, DC, in August. Another event is a continuation of the Entomological Society of America’s Grand Challenges event, “Pre-border Prevention: A New Conversation on Invasive Pest Pathways Through Trade” – which will take place in Orlando in November.

I repeat that we should support the international phytosanitary community’s efforts to raise political leaders’ awareness of the importance of preventing phytosanitary disasters.

However, at the same time, the international system that, for more than two decades, has governed trade, with all its associated phytosanitary risks and regulations, is falling apart.

The World Trade Organization – which is the basis for international trade rules – is under unprecedented threat. United States has blocked nomination of individuals to the World Trade Organization’s Dispute Panel. As of December 10, 2019 the Panel no longer has a quorum. As a result, experts expect countries to revert to the pre-WTO practice of bullying trade “partners” with whom they have a quarrel. They will probably erect tariffs and other barriers in order to force other parties to concede. Phytosanitary requirements might again be governed by individual countries’ bilateral agreements, leading to confusion and perhaps a “race to the bottom” in the name of facilitating trade.

Collapse of the WTO rules alarms me – despite my having criticized WTO restrictions on strong national phytosanitary measures over the past 25 years. (The restrictions were imposed by the WTO’s Agreement on the Application of Sanitary and Phytosanitary Measures – the SPS Agreement). For more details, see Fading Forests II. All-out country vs. country trade battles seldom put a priority on preventing the movement of pests. At least under WTO SPS, there has been a process for addressing pest problems.

Most phytosanitary issues – including development of international standards – are addressed under the International Plant Protection Convention. The IPPC is a separate organization from the WTO, so it might continue to function with fewer disruptions. Still, much of its clout comes from its recognition by the WTO SPS as the standard-setting body for plant health matters.

Of course, there are benefits associated with individual countries’ acting independently. Might the current collapse of trade rules allow the U.S. to adopt more stringent regulations governing introduction pathways of concern to us — for example, wood packaging? Can we hope that an administration focused on “America First” take aggressive phytosanitary actions to protect our agriculture and environment?

Unfortunately, I see no indications that the U.S. Department of Agriculture – much less other agencies – might seize this opportunity.

The United Kingdom has an even greater opportunity to act independently, since it is “Brexiting” the European Union in January 2020. In theory, the UK is now free to adopt its own phytosanitary measures. A House of Lords committee held extensive hearings to explore options in 2018.

While eminent plant pathologist Clive Brasier and others urged the UK to adopt more stringent rules based on a precautionary approach – for example, by banning imports of semi-mature trees with large root balls – the committee noted that the British government has often said that it wants to maintain “seamless” trade with the EU. It therefore seems unlikely that the UK will seize this opportunity to erect more effective phytosanitary barriers to prevent pest introductions to the islands.

Meantime, the European Union is making some mildly encouraging changes. Europe (including the UK) has the highest number of introduced tree-killing non-native pathogens of any continent – five times more than North America (Ghelardini 2017). Europe has a much more leaky phytosanitary system for plant imports than does the United States. See also Jung et al. (2015), Roy et al. (2014), the Montesclaros Declaration.

participants at the Montesclaros negotiation

In response to growing awareness of the plant pest threat, EU officials have gone through a multi-year process to strengthen phytosanitary rules governing movement of plants for planting (living plants, such as nursery stock). The process was described in Klapwijk et al. (2016) and discussed in my blog in October 2016. The new rules took effect in December 2019. The new European Commission regulation simplifies and harmonizes the “plant passport” system, under which plants are moved among EU member states. Plant imports that pose the greatest risk – called “priority pests” – are subject to enhanced measures concerning surveys, action plans for their eradication, contingency plans and simulation exercises. Plants for planting and plant products being imported into the EU will be subject to varying levels of restrictions, including prohibition of importation of those posing the highest risk. Less risky plants must be accompanied by a phytosanitary certificate issued by the phytosanitary agency of the exporting country (House of Lords report). The new system no longer depends on a list of harmful plant pests, but instead “sets out the conceptual nature of quarantine pests” and empowers the Commission to adopt measures to control certain pests (Klapwijk et al. (2016)).

Three years ago, Klapwijk et al. (2016) praised the new approach as a significant step forward. However, they note that the new rules still don’t provide for precautionary assessments of high-risk commodities. Nor do they actually restrict import of the highest-risk commodities, such as imports of large plants or plants in soil (my emphasis). Such restrictions still must be enacted separately. Organisms whose pest status is unknown will continue to be allowed into the EU. (See discussions of the impact of failing to curtail imports of “unknown unknowns” by Brasier (2008) and in Fading Forests II.

(While the U.S. also does not address organisms with unknown pest potential, it is much more stringent regarding sizes of plants, presence of soil or other growing media, and other issues. Furthermore, it has the NAPPRA process, which facilitates a more rapid response to emerging pest threats.)

Posted by Faith Campbell

SOURCES

Brasier CM. 2008. The biosecurity threat to the UK and global environment from international trade in plants. Plant Pathology 57: 792–808.

Ghelardini, L., Luchi, N., Pecori, F., Pepori, A.L., Danti, R., Della Rocca, G., Capretti, P., Tsopelas, P. , Santini, A. 2017. Ecology of invasive forest pathogens. Biological Invasions. June 2017

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;

Klapwijk, M., Hopkins, A.J.M., Eriksson, L. Pettersson, M., Schroeder, M., Lindelo¨w, A., Ro¨nnberg, J. Keskitalo, E.C.H., Kenis, M. 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

Roy, B.A., Alexander, H.M., Davidson, J., Campbell, F.T., Burdon, J.J., Sniezko, R., and Brasier, C. 2014. Increasing forest loss worldwide from invasive pests requires new trade regulations. Frontiers in Ecology https://cpb-us-e1.wpmucdn.com/blogs.uoregon.edu/dist/1/11561/files/2018/07/Roy-et-al-2014-Frontiers-12p4898.pdf

APHIS seeks comments on NAPPRA proposals

APHIS proposes to place numerous plant taxa on its list of plants for planting whose importation is “not authorized pending pest risk analysis” (NAPPRA). Unfortunately, the proposal comes too late for some pests; doesn’t apply to at least one significant pathway of entry; excludes some highly damaging newly detected pathogens; and too often applies only to agricultural pests. Nevertheless, the proposal is worth supporting – while mentioning those caveats.

APHIS is accepting comments on the data sheets justifying the proposed listings until 24 January. The Data sheets can be obtained here. We encourage you to comment.

APHIS’ Regulatory Framework

Under APHIS’ regulations in ‘‘Subpart— P4P’’ (7 CFR 319.37 through 319.37–14 …), APHIS prohibits or restricts the importation of “plants for planting” – living plants, plant parts, seeds, and plant cuttings – to prevent the introduction of “quarantine pests” into the US. A “quarantine pest” is defined in § 319.37–1 as a plant pest or noxious weed that is of potential economic importance to the United States and not yet present in the country, or is present but not widely distributed and is being officially controlled.

§ 319.37–2a authorizes APHIS to identify those plant taxa whose importation is not authorized pending pest risk analysis (NAPPRA) in order to prevent their introduction into the United States. If the plant taxon has been determined to be a probable invasive species, its importation is restricted from all countries and regions. If the taxon has been determined to be a host of a plant pest, the list includes (1) names of affected taxa, (2) the foreign places from which these taxa’s importation is not authorized, and (3) the quarantine pests of concern.

APHIS finalized a rule giving itself the authority to place plant taxa in the NAPPRA program in 2011; it has previously used this process twice to restrict imports of plant taxa – most recently in 2017.

Plant Taxa that Host a Damaging Pest or Pathogen

The proposed restrictions would apply to two plant families — Myrtaceae taxa (when destined to Hawai`i), and the subfamily Bambusoideae (bamboo); plus 43 other taxa that are likely to transport damaging insects, pathogens, or viruses.

`ohi`a in bloom; National Park Service photo

1) All plants in the family Myrtaceae that are destined for Hawai`i.

The proposed restriction is intended to counter the risk that additional strains of the `ohi`a rust pathogen Austropuccinia psidii might be introduced and prove more damaging to native Hawaiian vegetation than the strain already present on the islands. (See description of `ohi`a rust here.

`Ohi`a rust was detected in Hawai`i in 2005. Detection was followed by scientific studies to determine whether different strains exist and, if so, whether they posed a threat to Hawaiian vegetation. Under the circumstances, the proposed action is disturbingly tardy.

Worse, the pathogen was probably introduced to Hawai`i on imports of flower and foliage cuttings, rather than entire plants or propagules. Unfortunately, the section of APHIS’ regulations that governs imports of plants that can be grown (“plants for planting”) does not apply to imports of cuttings (including flowers). In the Federal Register notice, APHIS says it will issue a separate proposal to tighten regulations on imports of cuttings and flowers. I hope they move expeditiously on this rulemaking – which will be more cumbersome in even the best case because it requires a full rulemaking, not the expedited notice and comment process allowed under the NAPPRA program.

It is disturbing that the proposal does not include the two Ceratocystis species that are killing millions of `ohi`a trees in Hawai`i link to DMF writeup. It is true that these were identified relatively recently – in 2017. However, other plant taxa proposed for inclusion in the NAPPRA category were also detected or determined to be the cause of a disease as recently as 2017.

`ohi`a trees killed by Ceratocystis; Island of Hawai`i; photo by J.B. Friday, University of Hawai`i

2) APHIS proposes to include another pest that might attack a native Hawaiian plant, Phyllanthus distichus. Another species in the genus, P. saffordii is endemic to Guam; it is listed as endangered under the federal Endangered Species Act. Other Asian gooseberries in the Phyllanthus genus are grown in backyards in Hawai`i and other semitropical areas and there is some interest in expanding commercial uses.

3) APHIS proposes to include several plant taxa important in tropical agriculture because of the threat that imports of those plants will transport diseases or pests. These include two pathogens that threaten production of macadamia nuts (Neopestalotiopsis macadamiae and Pestalotiopsis macadamiae); and pests of breadfruit, lychee, and durian.

4) Some of the plant taxa that APHIS hopes to protect from new pests or pathogens by placing hosts in the NAPPRA category are invasive. These include – in Hawai`i – Syzygium jambos (rose apple). It is named as a host of two pests targetted by the proposed action – the `ohi`a rust pathogen Austropuccinia psidii and armored scale insect Myrtaspis syzygii.

Euonymus bungeanus (winterberry euonymus) is in the same genus as several plant species invasive across the continent. APHIS proposes to restrict its importation in order to prevent introduction of the Euonymus yellow mottle associated virus (EuYMaV), which has only that plant species as a known host.

5) APHIS also proposes to add to the NAPPRA category several plant taxa that could transport the Elm mottle virus (EMoV) because of the threat the virus poses to several European elm species – and presumably also to North American elms. The virus also attacks hydrangea and lilac.

In several cases, some of the primary hosts of the target pest or pathogen are already in NAPPRA for other reasons from some origins. Nearly all the woody hosts are already required to undergo post-entry quarantine – which presumably APHIS now considers to provide inadequate protection.

6) Also proposed are diseases or pests that threaten grapevines and tomatoes.

Several of the proposed taxa are already present in the US (including `ohi`a rust). Other proposed listings appear to be precautionary actions to protect plant taxa that USDA expects to be increasingly important economically in the future.

Plant Taxa Proposed Because They Appear Likely to be Invasive

APHIS has proposed 26 plant taxa for inclusion in the NAPPRA category because they might themselves be invasive. Of greatest ecological concern are two taxa of mangroves which had been introduced by early 20^th century plant explorer David Fairchild and have since been detected to be spreading in South Florida. These are Bruguiera gymnorhiza and Lumnitzera racemose. Also of concern is a vine that grows in Asian and Indian Ocean mangrove forests, Derris trifoliate.

Several proposed species are aquatic plants that can form dense mats.

Other taxa proposed appear to possibly threaten pastures or other agricultural uses.

Posted by Faith Campbell

Sudden Oak Death update

*P. ramorum*-infected rhododendron plants
Indiana Department of Natural Resources

As you may remember, in June and July I blogged about a troubling outbreak of sudden oak death pathogen Phytophtora ramorum in the nursery trade. The discovery was made by Indiana authorities, who carefully inspected plants being sold in the state. They discovered that rhododendron plants imported from an Oklahoma wholesaler included infected plants.

By the end of May, Indiana state inspectors had destroyed more than 1,500 rhododendrons and prohibited sale of another 1,500 plants pending determination of their health. [source: Indianapolis Star 29 May, 2019] Over the next months, APHIS determined that more than 50 rhododendron plants found in Indiana nurseries had been infected [California Oak Mortality Task Force Newsletter August 2019 ].

In the spring and summer, APHIS and state authorities alerted 28 states that they might have received plants from the suspect sources – the suppliers of the Oklahoma wholesaler — one nursery in Washington State and two nurseries from Canada. In the end, APHIS determined that plants exposed to the pathogen had been sent to 18 states – Alabama, Arkansas, Iowa, Illinois, Indiana, Kansas, Kentucky, Michigan, Missouri, Nebraska, North Carolina, Ohio, Oklahoma, Pennsylvania, Tennessee, Texas, Virginia, and West Virginia. As of late July, P. ramorum-positive nursery stock had been detected in nurseries in seven of these (Iowa, Illinois. Indiana, Kansas, Missouri, Nebraska, Oklahoma) plus Washington [California Oak Mortality Task Force Newsletter August 2019].

As I pointed out in the earlier blog, this is just the latest of several occasions since 2004 in which infected plants have been widely distributed by the nursery trade, despite federal and state regulations. Also, at the time of this outbreak, APHIS had just formalized several steps relaxing the regulations that had been implemented through Federal Orders adopted in recent years. (See the earlier blog for details.)

APHIS actions

I wonder at APHIS’ delay in explaining to stakeholders the situation– and what it is doing about it! APHIS provided minimal information to me – by email rather than a public announcement; this email came a month after Indiana announced detection of the pathogen to the public (as reported in my blog). APHIS issued an official notice even later, in mid-July [California Oak Mortality Task Force (COMTF) Newsletter August 2019]. Neither notice was timely, given the serious risks to both nursery and naturally growing plants from the pathogen.

It is now November and principal questions have not yet been answered. How did the inspection systems in Washington and British Columbia fail to detect the outbreaks before the plants were shipped? This lapse is especially worrisome because APHIS requires testing of soil and standing water, not just visual inspection of plants. Furthermore, rhododendrons are well known to be vulnerable to the pathogen and therefore are a specified focus of detection efforts!

The October COMTF newsletter includes a report by the Washington State Department of Agriculture that a nursery found positive in May will carry out a Critical Control Points (CCP) assessment. An “extensive fall certification survey” will also be conducted. Presumably, these efforts are aimed at determining how the outbreak occurred.

The Canadian Food Inspection Service (CFIA) described – briefly – its nationwide survey program. CFIA reported that one nursery was determined to be P. ramorum-positive in 2018, three in 2019. CFIA says that trace-forwards and trace-backs demonstrate that no Canadian nursery shipped infected plants to the U.S. in 2018 or 2019. So, apparently, none of the infected plants came from the Canadian nurseries.

I hope that Washington State and APHIS will soon determine the probable causes of the outbreak. APHIS should then promptly inform all stakeholders and engage them in developing improved programs and policies to minimize the likelihood that similar problems will occur again.

Phytosanitary officials from the states are apparently also seeking additional information from APHIS about what went wrong and how the agency plans to fix the problems. See the resolution adopted by the National Plant Board here

California Action

A much more positive development is that the California Department of Food and Agriculture (CDFA) has introduced a Voluntary P. ramorum Pre-Quarantine Program. This is a voluntary inspection program specifically for nurseries in California counties that are not currently regulated for the pathogen – but that might be put under regulation in the future. Inspections and sampling will be administered by county regulatory officials and samples will be processed by the CDFA Plant Pest Diagnostics Center. If P. ramorum is detected at a participating nursery, the PQP nursery may become a federally regulated establishment.

Broader Implications

As I pointed out in Fading Forests III, APHIS and the states have struggled to prevent spread of tree-killing pests once they have established in the country. Even regulated pests – such as Phytophthora ramorum and the emerald ash borer — have escaped the regulations. APHIS and/or the states have chosen not to engage on other pests, such as redbay ambrosia beetle and laurel wilt disease and the polyphagous and Kuroshio shot hole borers and associated Fusarium fungus. In other cases, some states have acted – and asked APHIS to not get involved – e.g., thousand cankers disease of walnut. This situation heightens the risk to our urban, rural, and wildland forests. Americans need a hard-nosed discussion of how we can improve coordinated efforts to prevent pests’ spread.

Posted by Faith Campbell

ISPM#15 – The Stamp is Not Effective as a Clue to Whether Wood Packaging is Pest-Free

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

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)

Kevin Harriger, US CBP. Presentations to the annual meetings of the Continental Dialogue on Non-Native Forest Insects and Diseases over appropriate years. See, e.g., https://continentalforestdialogue.org/continental-dialogue-meeting-november-2018/

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

https://www.joc.com/breakbulk/ispm-15-enforcement-leaves-shippers-no-good-nswers_20190717.htmlhttps://www.joc.com/breakbulk/enhanced-enforcement-ispm-15-costing-us-importers-millions_20190725.html

New Study: Non-Native Pests Threaten 2/5ths of 48 States’ Forest Biomass

redbay in Georgia killed by laurel wilt
photo by Scott Cameron

In August I posted a blog summarizing information on pest introductions and impacts gleaned over my nearly 30 years of engagement. Already, I need to post an update, with an alarming estimate of introduced pests’ impacts across the continent.

Fei et al. 2019 (see the full citation is at the end of this blog) estimate that the 15 most damaging introduced species threaten 41.1% of the total live forest biomass in the 48 conterminous states.

In fact, this might be an underestimate of the pests’ impacts on biomass loss. Fei et al. (2019) note several limitations in their data that might result in such an underestimate. These include:

1) Mortality rates – and impacts – may increase over several decades following the initial invasion.

2) For pests already established throughout nearly all their potential ranges, pest-induced biomass loss could be substantially underestimated because most of their hosts died long ago, before the FIA data began to be collected. Consequently, the actual loss of these tree species from the forest is much greater than has been measured by the study’s methods.

3) Mortality rates vary among species and regions, which might introduce errors. They cite European gypsy moth, in which relatively small areas of heightened mortality due to repeated defoliations are swamped by lower mortality rates across the chosen measurement area.

4) They considered only tree mortality, not crown or root dieback or reductions in tree growth.

5) They did not estimate carbon release to the forest floor as a result of defoliation.

6) Pest-related mortality rates may be underestimated due to salvage – although the authors did not observe evidence of substantial salvage efforts for most of these pests.

7) The data did not include losses from urban tree mortality.

Fei et al. estimate that more than 450 pests are established in the 48 conterminous states. This study excluded pests attacking palms; trees on U.S. Pacific and Caribbean islands; and pests native to portions of North America that are causing severe damage in naïve hosts – e.g., goldspotted oak borer. I did include the latter groups in my slightly larger estimate laid out in my August blog.

Fei et al. base their analysis on 83 of the introduced pest species considered to cause substantial effects on tree health and productivity and sometimes extensive tree mortality. (In my August blog, I described findings by another study by Guo et al (2019) that counted 91 species in that category.)

Fei et al. build on studies by a group of USDA Forest Service (USFS) scientists that I described in an earlier blog.

This team found that, nation-wide, non-native forest pests are causing an approximate 5% increase in total annual mortality by tree volume. They based their studies on analysis of 92,978 long-term plots maintained by the USDA Forest Inventory and Analysis program.

As noted above, the article cannot capture the full range of mortality in species affected by pests introduced decades ago. Chestnut blight, white pine blister rust, Port-Orford-Cedar root disease, beech bark disease, butternut canker, dogwood anthracnose, and European gypsy moths had all killed millions of trees before the USFS forest inventory plots were established. Fei et al. do form a solid basis for measuring some of the current impacts and projecting future ones.

The focus of the new article is on the amount of carbon being transferred from live biomass to dead organic matter as a result of the increased mortality caused by the 15 species with the highest impacts. This is arguably a more quantifiable measure of pests’ impacts than others’ approaches. Here, I focus more narrowly on the documentation of exacerbated mortality as measured by the loss of biomass. Added together, these 15 species have caused an additional (i.e., above background levels) tree mortality rate of 5.53 TgC per year [defined as terragrams of carbon]. This estimate of annual conversion of live biomass to dead wood is similar in magnitude to that attributed to fire (5.4 to 14.2 TgC per year) (Fei et al. 2019). Yet the fire threat gets much more attention – for both prevention and management.

It is important to remember that conversion of living biomass to dead wood does not result in an immediate release of carbon to the atmosphere. Atmospheric releases take place through decomposition which is both gradual and takes place at varying rates. Some of the carbon will remain in the soil. And, over time, some of the carbon storage capacity will be restored by compensatory growth in unaffected trees and the recruitment of new regeneration – although this faster growth is delayed by as much as two or more decades after pest invasions begin (Fei et al. 2019).

American elm being killed by “Dutch” elm disease
photo by Cheryl Kaiser, University of Kentucky; bugwood.org

The 15 species of introduced pests used in this analysis are laurel wilt disease, chestnut blight, butternut canker, dogwood anthracnose, emerald ash borer (EAB), Dutch elm disease, red pine scale, beech bark disease, hemlock woolly adelgid, balsam woolly adelgid, European gypsy moth, white pine blister rust, green spruce aphid, sudden oak death, and Port-Orford cedar root disease. Of these, the highest elevation in biomass loss – as measured by FIA plot data – was caused by EAB, Dutch elm disease, beech bark disease, and hemlock woolly adelgid. We know that elms and beech, at least, began dying decades before the FIA data began to be collected. So the reported mortality rates are an underestimate. This is especially true because beech mortality is highest in the first decade after invasion by beech bark disease.

Annual levels of biomass loss are virtually certain to increase. First, pests will spread to new host ranges and infestations in already-invaded ranges will intensify. As a result, substantial amounts of the hosts’ biomass are at risk of exacerbated mortality. As I noted at the top of the blog, the total amount of host biomass at risk from these 15 species is estimated to be 5,197 TgC – or 41.1% of the total live forest biomass in the 48 conterminous states. Further exacerbating future losses is the likelihood that additional pests will be introduced. I would add that pests not included in this analysis – e.g., polyphagous and Kuroshio shot hole borers and possibly the spotted lanternfly – are also likely to contribute to losses of live forest biomass.

Fei et al. (2019) did not attempt to determine the economic value of this biomass loss or to address other types of losses to ecosystem services.

Remember that a separate set of studies reported by Potter et al. (2019) (the CAPTURE project) also relied on data from the FIA plots to evaluate the impact of introduced pests. These studies focused on identifying the host species at greatest risk rather than highest-impact pests or biomass loss. I find it reassuring that the Fei and Potter studies – using different approaches – resulted in very similar species rankings. See my discussion of the Potter studies here.

Together, the teams led by Potter and Fei set clear priorities for addressing the threats from non-native pests. What we need now is action! See my recommendations in my recent “solutions” blog.

U.S. Capitol – inform your representatives that you want action to protect trees!

SOURCES

Fei, S., R.S. Morin, C.M. Oswalt, and A.M. 2019. Biomass losses resulting from insect and disease invasions in United States forests

Potter, K.M., M.E. Escanferla, R.M. Jetton, and G. Man. 2019a. Important Insect and Disease Threats to United States Tree Species and Geographic Patterns of Their Potential Impacts. Forests. 2019 10 304.

Potter, K.M., M.E. Escanferla, R.M. Jetton, G. Man, and B.S. Crane. 2019b. Prioritizing the conservation needs of United States tree species: Evaluating vulnerability to forest insect and disease threats. Global Ecology and Conservation. (2019)

Congressional Funding for Key USDA Programs (Assuming it Ever Passes)

Fiscal Year 2020 began on 1 October. Congress has not yet passed funding bills (appropriations) for the full year. Agencies are operating now on a short-term continuing resolution which expires on November 21^st. Meanwhile, representatives of the House and Senate will meet to reconcile the differences between the two bodies’ appropriations bills in hope that a year-long bill can be finalized by that time.

(Disagreement between President Trump and the Congress about funding for the border wall might prevent adoption of full-year appropriations bills and lead to another government shutdown.)

I report here the differences between House and Senate bills funding the USDA APHIS and Forest Service programs that are vital to addressing non-native forest pests.

APHIS

Over the years, I have complained that inadequate funding is a major cause of shortfalls in APHIS’ efforts to detect new invasions by tree-killing pests and to respond to those invasions in effective ways.

While funding levels are still too low, at least Congress is holding funding steady for APHIS for Fiscal Year 2020 (which began three weeks ago, on October 1^st). Both House and Senate bills maintain funding for two crucial programs at the FY19 levels:

“tree and wood pests” program – $60 million (this matches the FY19 level; it is $4 million above the funding provided in previous years); and
“Pest Detection” – $27.4 million.

The House provided slightly higher funding than the Senate for two other programs:

“specialty crops” (including sudden oak death) – $186.5 million in the House bill, $186 million in the Senate bill; and
“methods development” – $21.686 million in the House bill, $20.686 million in the Senate bill.

In the report accompanying its bill, the House called for two additional funding options to address emergencies. First, it set up a contingency fund of $470,000 to control outbreaks of insects, plant diseases, animal diseases and pest animals and birds to meet emergency conditions. Second, the report repeated language from past reports that authorizes the Secretary to take “such sums as may be deemed necessary” from other USDA programs in order to counter pest emergencies threatening any segment of U.S. agricultural production.

The Senate report addressed several high-profile tree pests. It called for complete eradication of the Asian longhorned beetle; mandated that APHIS report on its efforts to eradicate ALB and spotted lanternfly and to minimize spread of the polyphagous and Kuroshio shot hole borers; and to assist states that have recently detected the emerald ash borer. (This language is helpful, but it falls short of what I previously advocated – that APHIS continue efforts to prevent EAB spread, especially through movement of firewood.) The Senate report also urged APHIS to maintain FY19 level funding addressing the sudden oak death pathogen, in particular to improve understanding of the two strains of the pathogen present in Oregon’s forests link to blog to inform control and management techniques in wildlands. (Actually, management in wildlands falls largely to the Forest Service, with scientific input from both Agriculture Research Service and – to some extent – the NORS-DUC research nursery managed by APHIS.)

For a lengthier justification of my funding requests, see my earlier blog on APHIS funding

Funding for Resistance Breeding through NIFA

As I pointed out in my blog in May, the 2018 Farm Bill included an amendment (Section 8708) that establishes a new priority for a grant program managed by the National Institute of Food and Agriculture. The amendment would support restoration to the forest of native tree species that have suffered severe levels of mortality caused by non-native insects, plant pathogens, or other pests. The amendment affects the Competitive Forestry, Natural Resources, and Environmental Grants Program under Section 1232(c)(2) of the Food, Agriculture, Conservation, and Trade Act of 1990 (16 U.S.C. 582A-8, as amended. However, this program has not been funded for more than a decade. In my blog, I asked you to support a $10 million appropriation to NIFA to fund a competitive grant program for such forests restoration.

Neither the House nor the Senate provided funding for this program.

USFS

The House bill provides $277,155,000 for USFS Research and Development – nearly $20 million more than the Senate bill ($257,640,000). The House report links this increase to the recognition of the increasing risk to urban, rural, and wildland forests from insect and disease outbreaks and invasive plant infestations. The report calls on the Forest Service to develop a research program that addresses several priorities critical to forest health, including preventing the spread of disease and invasive species.

USFS engagement on pest issues with other federal agencies and state, local government, and private land managers is carried out through the Forest Health Management program under the State and Private Forestry division. The Senate bill and report are confusing because they have separated out salaries and other expenses. As a result, I can’t compare its figures to those in previous years or to those from the House. Partly for this reason, I urge you to support the House bill, which is quite clear in appropriating $103,736,000 for Forest Health Management, which is a programmatic increase of $19 million above the FY19 level and $29,919,000 above the budget request. I am encouraged by the House’ report, which encourages the Forest Service to address high priority invasive species, pests, and diseases, including the emerald ash borer and bark beetle infestations.

For longer explanations, see my earlier blog on USFS funding.

These bills show an increasing awareness of forest pest issues in key funding committees in both the House and Senate. Let’s reinforce this message – and spread it to the rest of Congress. Please contact your senators and representative and ask them to support these funding levels.

Posted by Faith Campbell

Solutions Suggested by 30 Years’ Work

Faith Campbell receives award for activism from National Association of State Foresters; 2016

For nearly 30 years I have documented bioinvasion threats and gaps, first in three Fading Forests reports (available here), then in five years of blogging. Here I pull together that information and suggest — in most cases reiterate — steps to address these threats and gaps. I list sources of discussion of the underlying issues – other than my reports and blogs – in references at the end of this blog.

My first premise is: robust federal leadership is crucial:

The Constitution gives primacy to federal agencies in managing imports and interstate trade.
Only a consistent approach can protect trees (and other plants) from non-native pests.
Federal agencies have more resources than state agencies individually or in any likely collective effort — despite decades of budget and staffing cuts.

My second premise is: success depends on a continuing, long-term effort founded on institutional and financial commitments commensurate with the scale of the threat. This requires stable funding; guidance by research and expert staff; and engagement by non-governmental players and stakeholders. Unfortunately, as I discuss below, funding has not been adequate or stable.

My third premise is that programs’ effectiveness needs to be measured, not just effort (see the NECIS document referenced at the end of the blog).

SPECIFICS

Preventing new introductions continues to be the most effective action. Mitigating options decrease and damages increase once a non-native pest has entered the country – much less become established (see Lovett et al. 2016 and Roy et al. 2014). I recognize that preventing new introductions poses an extremely difficult challenge given the volume and speed of international trade and the strong economic forces supporting free trade. These challenges have been exacerbated over several decades by the political zeitgeist – the anti-regulatory ideology, the emphasis on “collaborating” with “clients” rather than imposing requirements through regulations. Although the current “America First” policy might reduce import volumes and therefore reduce the invasive species threat to some extent, the anti-regulatory stance has only strengthened.

containers at the Port of Long Beach, California

Decades of cutting key agencies’ budgets and personnel are another factor. However, the damage to America’s natural systems is so great that we must try harder to find more effective strategies (See the Fading Forest reports; my previous blogs; Lovett et al. 2016; and APHIS annual reports – e.g., the 2019 report here)

Prevention

Despite adoption and implementation of new international and national regulations to stem pest introductions, introductions continue – although probably at a lower level than would otherwise be the case. Delays in adoption of regulations (documented in Fading Forests II and III and my two recent 30-years-in-review blogs have facilitated damaging introductions and spread.

Solutions

Stakeholders press USDA leadership to initiate rules intended to strengthen phytosanitary protection and expedite their completion
APHIS promote and facilitate analysis of current programs and policies by non-agency experts to ensure the agency is applying most effective strategies (Lovett et al. 2016).

Adoption of insufficiently protective regulations (documented in FFII, FFIII, two 30-years-in-review blogs) – adopted in part because APHIS is trying to “balance” trade facilitation and phytosanitary protection – has further contributed to damaging pests’ introduction and spread.

Solutions:

Boost priority of preventing pest introductions by amending the Congressional finding in the Plant Protection Act [7 USC 7701(3)] as follows

Existing language: “[I]t is the responsibility of the Secretary [of Agriculture] to facilitate exports, imports and interstate commerce in . . . commodities that pose a risk of harboring plant pests or noxious weeds in ways that will reduce, to the extent practicable, as determined by the Secretary, the risk of dissemination of plant pests and noxious weeds .… “

Amend to read as follows: “…. in ways that will ~~reduce~~ prevent, to the greatest extent ~~practicable~~ feasible, as determined by the Secretary, …” [emphasis added]

Adopt several actions to strengthen phytosanitary protections at the point of origin (Lovett et al. 2016)
Expand pre-clearance partnerships — as authorized for plants under Q-37 regulations and ISPM-36
Expand sentinel tree programs
Promote voluntary substitution of packaging made from materials other than solid wood.

APHIS doesn’t use the enforcement powers that it has under Plant Protection Act (see several of my past blogs)

Solutions:

CBP inspectors search for pests in a pallet; CBP photo

APHIS follow the lead of Customs and Border Protection and begin penalizing importers on the first instance of their wood packaging not being in compliance with ISPM#15 (see blog here).
APHIS prohibit use of wood packaging by countries and importers of categories of imports that – over the 13 years since implementation – have developed a record of frequent violations of ISPM#15.
APHIS use its authority per revised Q-37 regulations to negotiate with countries that export plants to the U.S. to establish “integrated measures” programs aimed at minimizing the risk of associated pests being transported to the U.S.
APHIS use its authority per revised Q-37 to place in the “Not Authorized for Import Pending Pest Risk Assessment (NAPPRA) “limbo” category genera containing North American “woody” plants (see Roy et al. 2014; Lovett et al. 2016).

Spread within the U.S.

The United States lacks a coordinated system to prevent pest spread within the country (see Fading Forests III Chapter 5). Even our strictest methods, like APHIS’s quarantines regulating interstate movement of goods, have failed to curtail spread of significant pests. The most obvious example is the emerald ash borer.

The regulations governing movement of the sudden oak death pathogen in the nursery trade have also failed: there have been periodic outbreaks in which the pathogen has been spread to nurseries across the country. Between 2003 and 2011, a total of 464 nurseries located in 27 states tested positive for the pathogen, the majority as a result of shipments traced from infested wholesalers. In 2019, plants exposed to the pathogen were again shipped to 18 states; eight of those states have confirmed that their plant retailers received infected plants (see my blog from summer here).

Another serious gap is the frequent failure of APHIS and states to adopt official programs targetting bioinvaders that will be difficult to control because of biological characteristics or cryptic natures – even when severe impacts are demonstrated. Recent examples include the laurel wilt disease complex, goldspotted oak borer, polyphagous and Kuroshio shot hole borers and associated pathogens, and even the spotted lanternfly (although the last has received significant funds from APHIS.)

redbay killed by laurel wilt disease, Georgia; photo by Scott Cameron

Solutions:

APHIS apply much more stringent regulations to interstate movement, based on a heightened priority for prevention in contrast to facilitating interstate trade. E.g., prohibit nurseries on the West Coast from shipping P. ramorum hosts to states where the pathogen is not established.
APHIS encourage states to adopt quarantines and regulations aimed at preventing spread of invasive pests to regions of the state that are not yet infested. For example, the sudden oak death pathogen in California and Oregon; the borers in southern California.
APHIS abandon plans to deregulate emerald ash borer and step up its support for state regulations on firewood.
APHIS stop dumping pests it no longer wants to regulate onto the states through the “Federally Recognized State Manage Phytosanitary (FRSMP) program”.
APHIS revise its policies so that the “special needs exemption” [7 U.S.C. 7756] actually allows states to adopt more stringent regulations to prevent introduction of APHIS-designated quarantine pests (see Fading Forests III Chapter 3).

To help fill the gaps, the states are trying to coordinate their regulations in some important areas. The most advanced example is the voluntary Systems Approach to Nursery Certification, or SANC program. APHIS has supported this initiative, including by funding from the Plant Pest and Disease Management and Disaster Program (see below). However, it is a slow process; USDA funds first became available in 2010. The states are trying to coordinate on firewood, but we don’t yet know what the process will be.

Funding shortfalls (See the three Fading Forests reports, my blogs about appropriations)
Increase APHIS’ access to emergency funds from the Commodity Credit Corporation by amending the Plant Protection Act [7 U.S.C. 7772 (a)] to include this new definition of “emergency”:

the term “emergency” means any outbreak of a plant pest or noxious weed which directly or indirectly threatens any segment of the agricultural production of the United States and for which the then available appropriated funds are determined by the Secretary to be insufficient to timely achieve the arrest, control, eradication, or prevention of the spread of such plant pest or noxious weed.

Although APHIS has the most robust prevention program of any federal agency, its funding is still inadequate. Stakeholders should lobby the Congress in support of higher annual appropriations.

The Plant Pest and Disease Management and Disaster Program (now under Section 7721 of the Plant Protection Act) has provided at least $77 million for tree-pest programs (excluding NORS-DUC & sentinel plant programs and other programs) since FY 2008. Much useful work has been carried out with these funds. However, these short-term grants cannot substitute for stable, long-term funding. I reiterate my call for stakeholders to lobby the Congress to provide larger appropriations to the APHIS Plant Protection program and Forest Service Forest Health Protection and Research programs.

Long-term Responses to Bioinvasive Challenge

More stakeholders are advocating raising the priority of – and providing adequate resources to – such long-term solutions as biocontrol and breeding trees resistant to pests and restoring them to our forests. Advocates include the state forestry agencies of the Northeast and Midwest, some non-governmental organizations, some academics, and individual USFS scientists. One effort resulted in inclusion of language in the 2018 Farm Bill (see blog here) – although this approach has apparently run into a dead end. The new emphasis on breeding has so far not been supported by agency or Congressional leaderships.

test planting of an American chestnut bred to be resistant to chestnut blight

Solutions:

USFS convene workshop of the federal, state, National Academy, academic, and NGO groups promoting resistance breeding in order to develop consensus on priorities and general structure of program.

Explicitly include evaluation of the CAPTURE Project’s (see blog here) efforts to set priorities to guide funding allocations and policies; and proposals for providing needed supportive infrastructure – facilities, trained staff in various disciplines. (See my blogs here.)

Report results of meeting to USDA leadership, Congress, and stakeholders

Then ensure implementation of the accepted approach by both Research and Development and Forest Health Protection programs. Include provisions to provide sustainable funding.

These proposed actions still do not address ways to correct the provisions of the international phytosanitary agreements (World Trade Organization and International Plant Protection Convention) that complicate – or preclude – efforts to prevent introduction of pests currently unknown to science. This issue is discussed in Fading Forests II. A current example is beech leaf disease (described here).

Continuing inadequate engagement by stakeholders

Most constituencies that Americans expect to protect our forests don’t press decision-makers to fix the problems I have identified above: inadequate resources, weak and tardy phytosanitary measures. Some of these stakeholders are other federal agencies, or state agencies – or their staffs. They face restrictions on how “political” they can be. But where are the professional and scientific associations, representatives of the wood products industry, forest landowners, environmental NGOs and their funders, urban tree advocates Efforts by me, USDA, and others to better engage these groups have had disappointing results.

As I have documented, groups of USFS scientists have made several attempts to document the extent of invasive species threats and impacts and to set priorities. So far, they have not gained much traction. Another USFS attempt, Poland et al. in press, will appear at the end of the year. Will this be more successful?

I detect growing attention to educating citizen scientists for early detection; but if there is an inadequate – or no – official response to their efforts won’t people become discouraged?

SOURCES

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, SL. Ladeau, and T. Weldy. 2016. NIS forest insects and pathogens in the US: Impacts and policy options. Ecological Applications, 26(5), 2016, pp. 1437–1455

National Environmental Coalition on Invasive Species “Tackling the Challenge.”

Poland, T.M., Patel-Weynand, T., Finch, D., Miniat, C. F., and Lopez, V. (Eds) (2019), Invasive Species in Forests and Grasslands of the United States: A Comprehensive Science Synthesis for the United States Forest Sector. Springer Verlag. (in press).

Roy, B.A., H.M Alexander, J. Davidson, F.T Campbell, J.J Burdon, R. Sniezko, and C. Brasier. 2014. Increasing forest loss worldwide from P&Ps requires new trade regulations. Front Ecol Environ 2014; 12(8): 457–465

Thirty Years of Tree Pest Analysis, Continued – Risks of New Introductions

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.

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 14^th 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.

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.

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