New “Plant Pest” Boss Soon to Take Office

Gregory Ibach


Gregory Ibach has been appointed USDA Under Secretary of Agriculture for Marketing and Regulatory Programs. He will supervise APHIS.

Mr. Ibach has strong ties to mainstream agriculture. A fourth-generation farmer (cow-calf and rowcrops), he has served as Nebraska’s Commissioner – or Deputy – of Agriculture under three governors – since 1999. His academic background is animal science and agricultural economics.

Mr. Ibach’s nomination was supported by 60 organizations, including the Farm Bureau, National Cattlemen’s Beef Association, and National Corn Growers.

The Senate Committee on Agriculture, Nutrition & Forestry held a very friendly hearing on Mr. Ibach’s appointment on October 5, 2017 2017 (video posted at the Committee website)  During the hearing – which was shortened by the need to attend to other Senate business – Senators’ attention focused on the farm conservation programs managed by the other nominee at the hearing (William Northey, nominee for Undersecretary for Farm and Foreign Agricultural Services). In response to several questions about marketing programs, Mr. Ibach said he needed to learn more about an issue.

In his formal testimony, Mr. Ibach noted the breadth of responsibilities under the jurisdiction of the Under Secretary for Marketing and Regulatory Programs and promised to find a balance between the two duties: representing and promoting the interests of farmers and ranchers; and overseeing some of the entities that regulate them. (Written testimony posted on Committee website — link above.)

“If confirmed, I will help the Secretary achieve his goals through ensuring sensible and effective regulations, responding to our customers in a timely and straight forward manner, focusing on plant and animal health program effectiveness, and fostering safe innovation that is farmer, consumer and environmentally sound.”

I summarize key points of the hearing below.

Committee Chairman Pat Roberts (R-KS) noted that foreign animal disease threats – such as avian influenza – have threatened agricultural production and asked what Mr. Ibach’s priorities would be for safeguarding animal health. Mr. Ibach said he takes very seriously APHIS’ responsibilities to keep diseases and pests out of the country and to control those that enter. He promised to learn about every program.

Ranking Democrat Debbie Stabenow (D-MI) asked Mr. Ibach about budgetary pressures. He responded by saying he would commit to doing the best job possible with available funds and to pursue efficiencies.

Amy Klobuchar (D-MN) was also concerned about disease threats to Minnesota’s large-scale turkey and hog producers.

John Hoeven (R-ND) pressed Mr. Ibach to find a solution to blackbirds as a threat to agriculture. Mr. Ibach said they are a problem in Nebraska, too. He promised to seek a “balanced” approach that preserved wildlife “when appropriate” while protecting farmers from destruction and disease threats.

Senator Leahy (D-VT) submitted questions pertinent to our concerns about tree-killing pests. Noting that Mr. Ibach had spoken about the pest threat to farmers, ranchers, and producers but had made no mention of the forest pests, Senator Leahy asked:

  • What familiarity do you have with APHIS’ work to keep out invasive forests pests that threaten our nation’s forests and the rural jobs and economy those forests support?

Mr. Ibach replied: I am familiar with the work that APHIS does in partnership with states to keep out and eradicate forest pests. In fact, in Nebraska, we have been working closely with APHIS prior to and since Emerald Ash Borer was found in the state for the first-time last year. These pests can absolutely devastate our forests, and if confirmed, I would work to make sure that APHIS’ pest programs, including those to protect the green mountains of Vermont, are effective.

  • Can you tell me how many wood and tree pests APHIS inspectors find every year, which theoretically should not have made it to our shores if importers were using the best available processes and phytosanitary practices to keep American agriculture and natural resources safe? And do you commit to looking into this issue and finding ways to safeguard both American agriculture and our natural resources?

Mr. Ibach replied: I do not have that data, but commit to learning more and working every day to protect American agriculture and natural resources if confirmed.

Senator Roberts said that the Committee would act soon to approve the nominations of Gregory Ibach and William Northey.


The Under Secretary for Marketing and Regulatory Programs sets the tone for APHIS’ efforts.  This person can prompt aggressive protection efforts … or block such efforts by opposition or indifference.  Let’s hope that Mr. Ibach plays the former role!


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.


Penalties for Importers Who Violate Wood Packaging Rules!

CBP inspection of wood packaging; CBP photo

On September 25, the DHS Bureau of Customs and Border Protection (CBP) announced that beginning on November 1, the agency would no longer eschew penalizing importers of non-compliant wood packaging until that importer had accumulated five such interceptions in the course of a year.

Beginning November 1, “responsible parties with a documented WPM violation may be issued a penalty under Title 19 United States Code (USC) § 1595a(b) or under 19 USC § 1592.”

As readers of this blog might remember, I have frequently fulminated against the “five strikes” policy.  The United States began full implementation of the international standard governing treatment of wood packaging (ISPM#15) 11 and ½ years ago. The U.S. and Canada began requiring China to treat its wood packaging nearly 18 years ago. Nevertheless, numerous shipments containing wood packaging that does not comply with the regulations continue to arrive at our borders – and to bring pests. As of February, only about 30 import shipments (out of nearly 21,000 shipments found to be in violation of ISPM#15 requirements) have received a financial penalty.

shipments of stone or tile are frequently supported by non-compliant wood packaging; photo (c) the Queen by right of Canada (CFIA)

In a blog I posted in February I described the continuing detections of pests in wood packaging. In summary, during Fiscal Years 2010 through 2016, CBP detected nearly 5,000 shipments of wood packaging that harbored a pest in a regulated taxonomic group. The APHIS interception database for the period FYs 2011 – 2016 contained 2,547 records for insect detections on wood packaging. The insects belonged to more than 20 families. A quarter were in the Cerambycid family; 11% were Buprestids. In a study of insect larvae removed from incoming wood packaging from the period April 2012 through August 2016, APHIS scientists evaluated 1,068 insects from 786 separate interceptions of non-compliant wood packaging. The wood packaging in all three datasets came from dozens of countries.


(Remember, the U.S. and Canada do not apply ISPM#15 to wood packaging moving between the two countries. Neither country inspects wood packaging from the other country at even the low rate of inspection applied to wood packaging coming from other countries – so we don’t know how many quarantine pests are moving in this high-volume trade.)


The Bureau of Customs’ action has partially fulfilled one of two recommendations that I made in the February blog. I applaud CBP’s action. However, neither CBP or APHIS has yet prohibited importers with records of repeat violations from using wood packaging – my second recommendation.


Note that the CBP decision applies Customs regulations; USDA has apparently not changed its policy of allowing importers to accumulate five (detected) violations in a calendar year before applying the civil penalties provided by the Plant Protection Act.  Why?


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

Posted by Faith Campbell

Worldwide Study Confirms ISPM#15 is not Protecting Forests – What Do We Do Now About Pests in Wood Packaging?


You know that the continuing pest risk associated with imports of wood packaging is among my biggest concerns. See, for example, fact sheets here and blogs here and here.

A new book about the family Cerambycidae (edited by Wang 2017; reference at end of blog) confirms that longhorned beetles continue to be introduced to many countries via this pathway, more than a decade after widespread implementation of the international standard governing wood packaging (ISPM#15). Furthermore, data from several countries confirm that China continues to fall short … but that problems are more widespread.

The Wang book finds that 16 outbreaks of the Asian longhorned beetle (ALB) were detected between 2012 and 2015.

Unless otherwise noted, the information provided here comes largely from the book’s chapter on biosecurity coauthored by Dominic Eyre and Robert A. Haack (see link below). Opinions stated are mine, unless specified otherwise.

In some cases – which I will note – further details are from my earlier posts.

While I think the risk of introduction of highly damaging pests via the wood packaging pathway is well documented in Wang (2017) and other publications, no one can truly quantify this risk because of shortcomings in countries’ data. Available data come primarily from countries’ records of pest “interceptions” – usually at points of entry.  However, interception data are inadequate to conclusively establish the lack of a threat for a particular trade or to provide a fair comparison of the relative threat of particular trades. Most interception databases have the following shortcomings (Eyre and Haack are summarizing points made by a third scientist – Lee Humble – in an earlier article):

(1) interception databases are not based on random sampling, which is necessary to measure the “approach” or “infestation” rate;

(2) inspections which find no pests are not recorded, so we cannot know what proportion of incoming shipments are infested;

(3) once inspectors have discovered a quarantine pest in a shipment, the consignments may be destroyed without further inspection, and thus other exotic organisms can be missed;

(4) only a small percentage of individual shipments are inspected; and

(5) organisms often are not identified to species due to difficulty of identifying larvae.


(1) trade volumes and sources can change rapidly;

(2) the number of consignments inspected varies from year to year in response to national and regional plant health and wider government priorities;

(3) the method and intensity of quarantine inspections can vary within and among countries and as well as over time; and

(4) different proportions of consignments from different trades can be inspected, reflecting the perceived quarantine risks of each trade.

Still, scientists try to analyze the available data because propagule pressure may be the most important factor in determining whether an exotic pest becomes established.

What have they found?

Data from both the United States and Europe document that problems of non-compliance continue in recent years – more than a decade after adoption of ISPM#15.

United States:

  • Since APHIS interception records began being computerized in 1985, Cerambycidae have been among the most frequently intercepted insect families associated with wood products and packaging. The top five countries for infested shipments during the period 1984 – 2008 were China, Italy, Mexico, Turkey and Spain. A country’s rank is linked in part to import volumes – which are very high for China, Canada, and Mexico. Because the  U.S. inspects very limited quantities of wood packaging from Canada, its absence from the top five may be misleading [discussed in my blog from February, here.

Another factor explaining these countries’ rankings is the continued – in fact increasing! – presence of pests in wood packaging accompanying imports of tile and quarry products (e.g., marble, slate). Many of these imports are from Italy, Spain, and Mexico. Interceptions on these imports increased significantly from the mid-1990s to 2008. The increase in these interceptions is most alarming because it shows USDA leaders have not yet taken effective action to curtail this risk, despite its being evident since record-keeping began.


  • Over the period Fiscal Years 2010 through 2016, the U.S. Bureau of Customs and Border Protection has detected nearly 5,000 consignments in which cases the wood packaging harbored a pest in a regulated taxonomic group. APHIS experts identified 2,500 insects taken from wood packaging during this period; a quarter were Cerambycids. A second APHIS analysis of a subset of the wood packaging-associated insects found examples from 39 countries, including 212 shipments from Europe; 130 shipments from Asia; and 341 shipments from the Americas – almost exclusively Mexico. [These detections are discussed in my blog from February, here.


Europe has had a similar experience.

  • Interception records included in EUROPHYT show 306 Cerambycidae interceptions on wood packaging over the period 1998 – 2013. The number of interceptions recorded in 2012 and 2013 are double those of all previous years. Each year, the majority are on wood packaging from China.
  • Most interceptions of ALB (distinct from detections of establishments) have occurred after the shipment cleared border inspection procedures, e.g., in warehouses.
  • As with the U.S., while the majority of non-compliant shipments are from China, the problem is worldwide: Europe has also found various species of longhorned beetles in wood packaging from various European countries (inside and outside the European Union), other Asian countries, Africa, Australasia, and the Americas.
  • Austria inspected 451 consignments of stone imports received April 1, 2013 – April 14, 2014. Forty-four consignments (9.8%) were found to be out of compliance with ISPM#15. Live Cerambycidae were found in 38 consignments (8%), including ALB. This finding confirms the widespread awareness that stone imports rank high for non-compliant wood packaging.


Regulatory Authorities’ Response (or lack thereof)


  • Since March 31, 2013, the European Union has required inspection of 90% of consignments of slate, marble, and granite and 15% of consignments of two other categories of stone imports.

CBP agriculture specialists in Laredo, Texas, examine a wooden pallet for signs of insect infestation. [Note presence of an apparent ISPM stamp on the side of the pallet] Photo by Rick Pauza
United States

  • As noted by Haack et al. (2014) (reference below), as of 2009, approximately 13,000 containers harboring pests probably enter the U.S. each year. That is 35 potential pest arrivals each day. [This issue is also discussed in the fact sheet and blogs here and here.
  • The United States has not specified an obligatory inspection rate for such high-risk imports as stone and tile. Instead, it relies on Customs and Border Protection to target import shipments suspected of being out of compliance based on past performance of importers, suppliers, and types of imports.
  • Several relevant issues are discussed in the blog in February 2017 (second blog linked to above). First, I noted that the U.S. Department of Homeland Security Bureau of Customs and Border Protection – over the seven-year period Fiscal Years 2010 through 2016 – has detected nearly 5,000 cases of wood packaging harboring a pest in a regulated taxonomic group. Comparing the estimate by Haack et al. 2014 with the CBP data indicates that Customs is detecting about 6% of all pest-infested shipments.
  • Furthermore, about 26% of infested wood pieces detected by CBP were found in wood that was marked as having been treated according to ISPM#15 requirements. What does this mean? Fraud? Accidental misapplication of the treatments? Or are the treatments less effective than hoped? What are USDA and other responsible agencies doing to clarify the causes?
  • CBP staff reported that only about 30 import shipments (out of nearly 21,000 shipments found to be in violation of ISPM#15 requirements) have received a financial penalty. How can USDA and Customs officials justify this failure to enforce the regulations?



What Can Be Done to Close Down the Wood Packaging Pathway


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

  • Prohibit imports in packaging made from solid wood (boards, 4 x 4s, etc.) from foreign suppliers which have a record of repeated violations over the 11 years ISPM#15 has been in effect (17 years for exporters from Hong Kong & mainland China). Officials should allow continued imports from those same suppliers as long as they are contained in other types of packaging materials, including plastic, metals, or fiberboards.
  • Fine an importer for each new shipment found to be out of compliance with ISPM#15 in cases when the foreign supplier of that shipment has a record of repeated violations.


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


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


What You Can Do

  • Tell your member of Congress and Senators that you are worried that our trees are still being put at risk by insects arriving in wood packaging. Ask them to urge the USDA Secretary Sonny Perdue to take the actions outlined above in order to curtail introductions of additional tree-killing pests.
  • Talk to your friends and neighbors about the threat to our trees. Ask them to join you in communicating these concerns to their Congressional representatives and Senators.
  • Write letters to the editors of your local newspaper or TV news station.


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


Other Introduction Pathways for Cerambycids

tree removals in Tukwilla, WA to eradicate citrus longhorned beetle; photo by Washington State Department of Agriculture

Plants for planting

Other studies have confirmed that importation of living plants (called by regulators “plants for planting”) is a high-risk pathway for introducing tree-killing pests. See the Eyre and Haack chapter for a summary.

This is as true for highly damaging Cerambycids as for other types of plant pests. One of the most damaging is the citrus longhorned beetle (CLB) (Anoplophora chinensis). CLB [] poses an even greater threat to North American forests than ALB – it has a wider host range and climate-matching models show that it could establish across most of the United States. CLB were detected in a nursery in Tukwilla, Washington, in 2001; the pest was eradicated. Nine CLB outbreaks have been detected in Europe; three are considered eradicated (Eyre & Haack 2017).

Eyre and Haack (2017) report that in Europe of the 455 Cerambycidae intercepted over the period 1998 – 2013, 54 were on imported in living plants. These included probably 49 citrus longhorned beetle (CLB). Most were detected primarily on maple nursery stock that originated China (32), with smaller numbers from other countries, including Netherlands (8), and Italy (where CLB has been established).

New Zealand has intercepted 74 CLB on plants for planting over the 28 year period 1980 – 2008.  One third of this total was intercepted in 2008.


Authorities’ Responses (or lack thereof)


  • Since 2012, the European Union has required that 10% of CLB host plants imported into the European Union should be destructively sampled (that is, dissected to see whether insects are present internally).
  • This requirement supplements a broader requirement that plants for planting be treated as a high risk commodity. Member states are required to inspect all incoming P4P consignments. This requirement is, however, undermined by much more lenient requirements regarding movement of plants among EU member states – some genera are not regulated … others are controlled by Plant Passports – an industry-led scheme.  [For more on this issue, see my blog from October 2016 here.


United States

  • APHIS issued a Federal order tightly restricting imports of CLB hosts from Europe in 2013 – four years after a CLB outbreak was detected in a part of the Netherlands which is a center for the production of hardy ornamental nursery stock for European and probably American markets.
  • APHIS proposed to revise its overall plant importation regulations (the “Q-37 regulations) to rely more on integrated management by the exporting nurseries in contrast to port inspections. This rulemaking has stalled. [See my blog about this here.]


Finished Wood Products

While no country is keeping comprehensive records, finished wood products have transported longhorned beetles.  Eyre and Haack (2017) concluded that upholstered furniture presents one of the highest risk among the finished wood products – partly because imports are rising rapidly, partly because insect-damaged wood can be hidden under the upholstery. New Zealand found that some Asian manufacturers place good quality wood on visible surfaces and poor quality timber (insect damaged and bark covered) in internal sections. Officials inspected 49 couches and found that 30 had wood with bark, 19 had insect contaminants, and 32 had visible insect damage. Fungal samples were isolated from 11 of the couches. They found 4 longhorned beetles.



Wang, Q. (Ed.). 2017. Cerambycidae of the world: biology and pest management.  Boca Raton, FL: CRC Press

The chapter on biosecurity is available here:

A chapter on Cerambycid impacts in urban and rural forests is available here:


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.


Posted by Faith Campbell

Invasive “hot spot” study confirms vulnerable places, causes of introductions

removing Miconia from Hawaiian forest; courtesy of the Nature Conservancy of Hawai`i

A recent article by Wayne Dawson and 24 coauthors (see reference at the end of this blog) provides the first-ever global analysis of established alien species. They studied the diversity of established alien species belonging go eight taxonomic groups – amphibians, ants, birds, freshwater fish, mammals, reptiles, spiders and vascular plants – across 609 regions (186 islands or archipelagos, and 423 mainland regions).

The analysis found that the highest numbers of established alien species in these taxonomic groups were in the Hawaiian Islands, New Zealand’s North Island and the Lesser Sunda Islands of Indonesia. The Hawaiian Islands have high numbers of invasive species in all of the eight groups studied. In New Zealand, the highest numbers were invasive plants and introduced mammals that prey on the native birds.

Florida is the top hotspot among mainland regions. Florida is followed by the California coast and northern Australia.

Burmese python in the Florida Everglades; photo by U.S. Fish & Wildlife Service


 Invasive species hotspots were found mainly on islands and in coastal regions of mainland areas. The lead author, Dr. Wayne Dawson, a researcher at Durham University’s Department of Biosciences, suggested that the greater invasive species richness in coastal regions probably results from higher rates of species introductions to port areas compared to interior regions.

Island regions have, on average, higher cross-taxon invasive species richness. This cross-taxon richness on islands tends to be higher for those islands further from continental landmasses. The authors suggest that such oceanic islands might be more likely to import large quantities of goods from foreign sources than islands close to continents, thus experiencing higher propagule pressure.



Regions with greater wealth (measured as per capita GNP), human population density, and area have higher established alien richness. These effects were strongest on islands. The authors suggest that wealth and human population density might correlate with higher numbers of species being brought to the region through trade and transport.

On mainlands, cooler regions have higher richness. I think this might reflect history – centuries of colonial powers importing plants and animals. However, colonial powers also introduced species to tropical regions.  In contrast, on islands warmer and wetter regions have higher richness of invasive species.



The authors conclude that cumulative numbers of invasive species at a particular location are driven to a greater extent by differences in area and propagule pressure than by climate. The model that best explains cross-taxon invasive species richness combines per capita GDP, population density and sampling effort. Other important factors are area of the region, mean annual precipitation, and whether a region is on a mainland or island(s).

The study results show that, per unit increase in area, per capita GDP, and population density, invasive species richness increases at a faster rate on islands than on mainlands. This might be confirmation of the longstanding belief that islands are more readily invaded than mainlands, although the authors caution that a rigorous test of this explanation would require data on failed introductions.

The authors call for additional research to understand whether these effects arise because more species are introduced to hotspot regions, or because human disturbance in these regions makes it easier for the newcomers to find vacant spaces and opportunities to thrive.


I think it would be helpful to compare the findings on invasive species richness in specific regions to data on historic patterns of trade and colonization to strengthen our understanding of the importance of propagule pressure in determining invasion patterns.


Increasing Confirmation of Significance and Breadth of Invasive Species Threat

The Dawson et al. study is the latest in a series of analyses of global or regional patterns in invasive species. I have blogged previously about several of these:

  • Bradshaw et al. 2016 concluded that invasive insects alone cause at least $77 billion in damage every year, a figure they described as a “gross underestimate”.
  • A study by Hanno Seebens and 44 coauthors showed that the rate of new introductions of alien species has risen rapidly since about 1800 – and shows no sign of slowing down. Adoption of national and international biosecurity measures have been only partially effective, failing to slow deliberate introductions of vascular plant species, birds, and reptiles, and accidentally introduced invertebrates and pathogens. Like Dawson et al, Seebens et al. found a strong correlation between the spread of bioinvaders introduced primarily accidentally as stowaways on transport vectors or contaminants of commodities (e.g., algae, insects, crustaceans, molluscs and other invertebrates) and the market value of goods imported into the region of interest.
  • Liebhold et al. 2016(see reference below) studied insect assemblages in 20 regions around the world. They found that an insect taxon’s ability to take advantage of particular invasion pathways better explained the insect’s invasion history than the insects’ life-history traits. (The latter affect the insect’s ability to establish in a new ecosystem.)
  • Maartje J. Klapwijk and several colleagues note that growing trade in living plants and wood products has brought a rise in non-native tree pests becoming established in Europe. The number of alien invertebrate species has increased two-fold since 1950; the number of fungal species has increased four-fold since 1900.
  • Jung et al. (2015) studied the presence of Phytophthora pathogens in nurseries in Europe. They found 59 putatively alien Phytophthora taxa in the nurseries. Two-thirds were unknown to science before 1990. None had been intercepted at European ports of entry when they were introduced. Nor have strict quarantine regulations halted spread of the quarantine organism ramorum.
  • A report by The World Conservation Union (IUCN) on World Heritage sites globally found that invasive species were second to poaching as a threat to the sites’ natural values. Of 229 natural World Heritage sites examined, 104 were affected by invasive species. Island sites – especially in the tropics – were most heavily impacted.
  • Another report by IUCN found that invasive species were the second most common cause of species extinctions – especially for vertebrates.


These studies demonstrate that

  • Invasive species have become a significant threat to biological diversity and ecosystem services around the world – one that continues to grow.
  • The recent spate of studies originating in Europe probably reflects recent recognition of the continent’s vulnerability – as seen, inter alia, in the proliferation of tree-killing Phytophthoras.
  • Human movement of species – propagule pressure – whether deliberately or due to inadequate efforts to manage trade-related pathways – explain the bulk of “successful” introductions.
  • Economic activity drives introductions, so areas at highest immediate risk are urban areas and other centers receiving high volumes of imports and visitors. Among troubling trends in the future is rapid global urbanization – along with rising economic interdependency.
  • Efforts to curb these movements – at the national, regional, and international levels – have failed so far to counter the threat posed by invasive species of nearly all taxonomic groups.

In my view, the requirements that phytosanitary measures “balance” pest prevention against trade facilitation results in half measures being applied – and half measures achieve halfway results. For example, the U.S. does not require that packaging be made from materials that cannot transport tree-killing pests. The USDA has moved far too slowly to limit imports of plant taxa that pose a risk of either being invasive themselves or of transporting pests known to be damaging.


Conservationists should focus on building political pressure to strengthen regulations and other programs intended to curtail this movement. No other approach will succeed.



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

Dawson, W., D. Moser, M. van Kleunen, H. Kreft, J. Perg, P. Pyšek, P. Weigelt, M. Winter, B. Lenzner, T.M. Blackburn, E.E. Dyer, P. Cassey, S.L. Scrivens, E.P. Economo, B. Guénard, C. Capinha, H. Seebens, P. García-Díaz, W. Nentwig, E. García-Berthou, C. Casal, N.E. Mandrak, P. Fuller, C. Meyer and F. Ess. 2017. Global hotspots and correlates of IAS richness across taxon groups. Nature Ecology and Evolution Vol. 1, Article 0186. DOI: 10.1038/s41559-017-0186 |


Jung,T., L. Orlikowski, B. Henricot, P. Abad-Campos, A.G. Aday, O. Aguin Casa, J. Bakonyi, S.O. Cacciola, T. Cech, D. Chavarriaga, T. Corcobado, A. Cravador, T. Decourcelle, G. Denton, S. Diamandis, H.T. Doggmus-Lehtijarvi, A. Franceschini, B. Ginetti, M. Glavendekic, J. Hantula, G. Hartmann, M. Herrero, D. Ivic, M. Horta Jung, A. Lilja, N. Keca, V. Kramarets, A. Lyubenova, H. Machado, G. Magnano di San Lio, P.J. Mansilla Vazquez, B. Marais, I. Matsiakh, I. Milenkovic, S. Moricca, Z.A. Nagy, J. Nechwatal, C. Olsson, T. Oszako, A. Pane, E.J. Paplomatas, C. Pintos Varela, S. Prospero, C. Rial Martinez, D. Rigling, C. Robin, A. Rytkonen, M.E. Sanchez, B. Scanu, A. Schlenzig, J. Schumacher, S. Slavov, A. Solla, E. Sousa, J. Stenlid, V. Talgø, Z. Tomic, P. Tsopelas, A. Vannini, A.M. Vettraino, M. Wenneker, S. Woodward and A. Perez-Sierra. 2015. Widespread Phytophthora infestations in European nurseries put forest, semi-natural and horticultural ecosystems at high risk of Phytophthora disease. Forest Pathology.


Klapwijk, M.J., A.J.M. Hopkins, L. Eriksson, M. Pettersson, M. Schroeder, A. Lindelo¨w, J. Ro¨nnberg, E.C.H. Keskitalo, M. Kenis. 2016. Reducing the risk of invasive forest pests and pathogens: Combining legislation, targeted management and public awareness. Ambio 2016, 45(Suppl. 2):S223–S234  DOI 10.1007/s13280-015-0748-3  [ ]


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


Seebens, H. et al., 2017. No saturation in the accumulation of alien species worldwide. Nature Communications. January 2017. [ ]



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.


Posted by Faith Campbell



Insects & Pathogens Introduced Via Plant Imports – Let’s Collaborate to Understand Risk


map showing locations in Hawaii Volcanoes National Park of ʻōhiʻa infested by rapid ʻōhiʻa death; NPS map available here

The U.S. Department of Agriculture’s adoption of a new list of plant species barred from importation pending pest risk assessment after a four-year wait (NAPPRA) [see my previous blog from June 21, here] prompts me to review what I know about pests associated with plant imports – and to appeal for collaboration among non-USDA scientists to improve our understanding of current  risks. Therefore I’m sharing some pest import and establishment data. I welcome the opportunity to work with experts to evaluate the level of risk and other matters that might be extracted from these data. Contact me to explore how we might work together.

As was pointed out by Eschen et al. 2015 (see list of sources at the end of this blog), most countries’ data on the “plants for planting” pathway are inadequate to allow an assessment of phytosanitary measures’ efficacy in preventing pest introductions. The authors stressed the need for data on:

  1. plant imports at the level of genus, including plant type and origin;
  2. pest arrival rates on each of these categories of plant imports; and
  3. pest establishments.

In the apparent absence of agencies’ efforts to close these data gaps, I propose that we work together, using available information, to improve our understanding of the current level of risk. Perhaps we can agree on which pest species are real red flags; decide which pathways most need new policy approaches; and reach conclusions about the implications of holes in the data.

  1. What Do We Know About Plant Imports?

The U.S. imports approximately 2.5 billion plants each year. The plants most likely to transport insects or pathogens that would attack North American trees and shrubs are woody plants. According to Rebecca Epanchin-Niell, during the period FY2010-FY2012, Americans imported each year more than 300 million woody plant units, belonging to about 175 genera.

Marcel Colunga-Garcia and colleagues analyzed plant import data for the period 2010-2012. They studied maritime (ship-borne) containerized plant imports, which represented 64.4 percent of the total value of all “plants for planting” imported into the U.S. in 2010, excluding imports from Mexico and Canada. The types of plants shipped in this way include rooted plants in pots; bare root plants; bulbs and tubers; root fragments, root cuttings, rootlets or rhizomes; rooted cuttings; unrooted cuttings; and budwood/graftwood.

Measuring by the plants’ import values, Colunga and colleagues determined that New York and Los Angeles metropolitan areas together import 60 percent of these plants; not all plant imports are routed through Miami – as is often assumed.

Second, these data show which states are the ultimate destination for relatively large volumes of certain types of plants. Thus, the top five states for receipt of rhododendrons and azaleas were Michigan, Oregon, California, New York, and New Jersey. Michigan received almost twice as many plants (measured by value) as New Jersey. The top three states for receipt of “fruit and nut trees and shrubs” were Florida, Louisiana, and Washington – all at nearly $1 billion or higher. California and North Carolina ranked fourth and fifth, but at values of only $200,000. It is clear from these data that contaminated plants could deliver pests virtually anywhere in the country.

Because my focus is on insects or pathogens that threaten native trees, I wish to separate those from pests that attack primarily herbaceous plants. (Of course, herbaceous plants are important components of ecosystems, as well as premier agricultural and horticultural crops! I do not mean to imply that pest threats to herbaceous plants are not important.)

About nine million of the 300 million woody plants imported to the U.S. each year belong to genera which also contain species of trees native to North America. A larger number of plants – 224 million – were in the same family as a North American native tree (Epanchin-Niell 2017). In other words, about 75% of the woody plants imported each year were in the same family as at least one species of tree native to North America.

Since plants in the same genus are more likely to transport damaging pests that would attack North American trees and shrubs, some have suggested that all such imports should be prohibited temporarily, using the NAPPRA process.

  1. What Do We Know About Pest Arrivals? (Including Detection Difficulties)

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 — a pathway that has received far more international and U.S. regulatory attention for years. This finding is similar to that of a study in New Zealand, which found that 14 percent of consignments of plants were infested – primarily with pathogens (Epanchin-Niell 2017). Worse, though, Liebhold et al. found that a high percentage of pests associated with a plant shipment is not detected by the inspectors, although APHIS has disputed this finding.


At my request, APHIS analysts compiled a list of imported woody plant genera on which pests were detected during fiscal years 2011-2016. Of the 360 quarantine pests listed, only 34 were designated as “disease” (nine percent of the total). I suspect this is significantly below the actual number entering the country.


Table 1. Overall number of pest detections recorded*

Fiscal Year # of records # of countries of origin for shipments found to be infested
2011 133 16
2012 110 14
2013 42 12
2014 27 9
2015 45 12
2016 14 5


* My totals do not include shipments from Puerto Rico; there were six pest detections on plants from the Commonwealth.

I cannot explain why the total number of detections shown in Table 1 nor – especially – the number of countries from which these infested shipments arrived fell so dramatically in FY2016. If APHIS was focused on inspecting the highest-risk shipments in FY15 and FY16, shouldn’t the number of interceptions have risen?


Pathogens are probably undercounted in Table 2 because inspectors experience great difficulty in detecting pathogens during port-of-entry inspections. For example, the genus Phytophthora does not appear in the database of port interceptions, yet we know that Phytophthora are being introduced. Also, the database does not contain the genus Rhododendron. It seems unlikely that no quarantine pests were detected on a shipment of Rhododendron over that six-year period.


Table 2. Types of Pests Intercepted

Disease                        34

Insect                           290

Mite                             20

Mollusk                       23

Nematode                    2



APHIS’s interception records are not designed as a statistically valid sample for determining the total number of pests on shipments because, for example, inspection priorities and resultant inspection criteria  change over time. Since 2015 APHIS has focused more on higher-risk shipments. Before, a specified percentage of all imports was inspected. For these reasons, interception records cannot be used to evaluate the overall risk of pests being imported along with “plants for planting” in any given year. Nor can APHIS’ interception records be compared over time.

Obviously, the numbers of pests detected on a specific type of import will reflect several factors, especially the volume of imports and the intensity of inspection. This bias in the data is reflected in the high number of pest interceptions from Central American countries – from which the U.S. imports very large volumes of plants. Two hundred twenty of the 385 pest detections recorded over the six-year period (57 percent) were on plants shipped from Costa Rica or Guatemala. Canada ranked third, with 35 pest detections (nine percent of the total).

That said, each record reflects a detection of a taxon of animal or pathogen that APHIS considers to be a “plant pest”. Each time a particular species is detected in a shipment, it is recorded. If more than one species is detected in a shipment, each species is reported separately. Therefore,

  • the number of detection records does not equal the number of shipments found to be infested;
  • the records do not reveal the number of specimens of each named taxon – either in an individual shipment or in total; and
  • the number of times a taxon appears in the database does indicate how many shipments were found to be infested by that taxon.



  1. Principal Threats to North America’s Native Trees and Shrubs

APHIS and I agree that our focus should be on those pests likely to have significant consequences if they are introduced. This risk of impact depends on climate, presence of probable hosts in the U.S., and other factors. Among the highest risk sources of imports for most the U.S. will be temperate countries, like those below. APHIS assigns a lower rating of risk to pests that are likely to be established in the U.S. already or to establish naturally – e.g., pests native to northern Mexico near the U.S. border.


Table 3. Main Temperate Countries of Origin for Infested Shipments by Year

FY2011:  Germany, Japan, Turkey, Netherlands, France, Pakistan, Canada, New Zealand

FY2012:  Israel, Canada, South Korea, China, Chile, Netherlands

FY2013:  France, Canada, Belgium, China

FY2014:  China, Canada, South Africa, Portugal

FY2015:  China, Germany, Netherlands, Canada, France, Australia

FY2016:  Canada



We can also look at the host plants on which pests are being intercepted to think about threats. Table 4 shows these. Presumably, the volume of trade in these genera, from the countries concerned, is sufficient to preclude any listing of these hosts under the NAPPRA regulatory process (see blog from June 21).


Table 4. Host Genera on which Pests Were Intercepted, Including only Genera Native

to North America or U.S. Islands or Important in Ornamental Plantings

 Plant genus                 # records — countries of origin — types of pests

Acer                             7 — primarily Canada; also Netherlands & Korea – 2 disease, 4 insect, 1 mite

Buxus                           3 – all Canada – 2 insect, 1 mollusk

Camellia                      2 – France – 1 disease, 1 mite

Chamaecyparis                        1 – Canada; mite

Cycas revoluta             8 – Honduras, Costa Rica, Dom. Rep. – insects

Fagus                          6 – Netherlands, Belgium; insects (aphids primarily)

Hibiscus                       4 – France, Tahiti, Canada – 1 disease, 1 insect, 1 mite, 1 mollusk

Ilex                              3 – Canada & NL – 2 insects, 1 disease

Liriodendron               2 – Canada – insects

Magnolia grandifolia  1 – South Africa – insect

Opuntia                       6 – Mexico – insects

Picea                           7 – Canada – insects (primarily aphids)

Thuja                           6 – Canada – insects

Tilia                             2 – Canada – mollusk


  1. What Else Do We Know?

If we look at pests introduced via all pathways, unlike those above, U.S. pest-establishment data show that plant pests continue to be introduced, but at a slower pace in recent years. In its Implementation Plan for Section 10201 of the Food, Conservation and Energy Act of 2008, USDA APHIS said that between 2001 and summer 2008, 212 pests were reported as new to the United States – an average of 30 new pest introductions each year. An APHIS database of plant pests “newly detected” during fiscal years 2009 – 2013 listed approximately 90 new taxa of plant pests as detected during this period – approximately 22 each year. In its annual report for 2016, the agency reported detecting 16 species of plant pests not previously detected in the U.S.

I think that approximately 37 of the 90 “new” pests detected over the 2009-2013 period were probably introduced via imports of plants, cuttings, or cut foliage or flowers. These include all the viruses, fungi, aphids and scales, whiteflies, and mites. I have asked APHIS to give me a database of newly detected plant pests for fiscal years 2014-2015, but the agency has not done so.

Among tree-killing pests introduced over the past 160 years, approximately 69% were introduced via the live plant trade. Liebhold et al. 2012 found that 95% of sap feeders, 89% of foliage-feeding insects, and 47% of pathogens were introduced via this pathway.

Pathogens are probably undercounted here, too, since those that do not cause massive damage are probably overlooked. Of the approximately 90 pests newly detected  2009-2013, ten were fungi, four were viruses, and two were rusts (18 percent of the total).

The genus Phytophthora does not appear in the database of “newly detected” pests. Yet we know that Phytophthora are being introduced. We know that, in 2012 a Phytophthora new to the United States — Phytophthora tentaculata — was detected on nursery-raised herbaceous plants in California. Follow-up studies have detected several additional Phytophthora taxa that might be new to the United States. One, P. quercina, had previously been reported only in Europe and Western Asia. The other putatively new taxa are still being evaluated as to whether they are previously unknown species or hybrids, and whether they are native to California or elsewhere in the United States, or are of alien origin.


The presence of the EU1 strain of Phytophthora ramorum in several nurseries in Washington, California, and most recently Oregon is also evidence that introductions of this species have continued since it was designated as a regulated pest in 2003.


Another pathogen that has apparently not been included in the official data is the fungus which causes rapid ʻōhiʻa death – a strain of Ceratocystis fimbriata. Scientists do not yet know whether this strain was introduced directly to Hawai`i on a recently-imported, asymptomatic plant; or whether the strain evolved from one or more different strains introduced to Hawaiʻi recently or longer ago.


Can you help evaluate the level of risk associated with various plant taxa, types, and origins? and other matters that might be extracted from these data. Perhaps we can agree on which pest species cause greatest concern; decide which pathways most need new policy approaches; and reach conclusions based on holes in the data. Can we use the data on pest taxa that underlie this summary – data which I have – to strengthen the case for USDA to promptly finalize revision of its “plants for planting”  (“Q-37”) regulations (see my blog from June 21 and Chapter 4 of the Fading Forests report?


Contact me to explore how we might work together.


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.




Colunga-Garcia M, Haack RA, Magarey RD, Borchert DM (2013) Understanding trade pathways to target biosecurity surveillance. In: Kriticos DJ, Venette RC (Eds) Advancing risk assessment models to address climate change, economics and uncertainty. NeoBiota 18: 103–118. doi: 10.3897/neobiota.18.4019


Epanchin-Niel, R.S. 2017. Presentation to 28th USDA Interagency Research Forum on Invasive Species. January 2017.


Eschen, R., K. Britton, E. Brockerhoff, T. Burgess, V. Dalley, R.S. Epanchin-Niell, K. Gupta, G. Hardy, Y. Huang, M. Kenis, E. Kimani, H.-M. Li, S. Olsen, R. Ormrod, W. Otieno, C. Sadof, E. Tadeau, M. Theyse. 2015. International variation in phytosanitary legislation and regulations governing importation of plants for planting. Environmental Science and Policy 51 (2015) 228-237

Liebhold, A.M., E.G. Brockerhoff, L.J. Garrett, J.L. Parke, and K.O. Britton. 2012. Live Plant Imports: the Major Pathway for Forest Insect and Pathogen Invasions of the US.



Surprise! USDA Through APHIS moves on NAPPRA regulations


USDA headquarters; F.T. Campbell

To my complete surprise, USDA APHIS has finalized a four-year-old proposal to temporarily prohibit importation of 56 taxa of plants: 22 that are likely to be invasive and 34 that are hosts of eight insects, pathogens, or other types of plant pests.

On June 19, APHIS published a notice in the Federal Register announcing that APHIS had finally acted on a proposal initially published on May 6, 2013. To view the datasheets APHIS prepared and the comments APHIS received, go here.

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 is not widely distributed and is being officially controlled.

Section 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. As regards plant taxa that have been determined to be probable invasive species, such importation is restricted from all countries and regions. For taxa that have been determined to be hosts of a plant pest, the list includes (1) names of the taxa, (2) the foreign places from which the taxa’s importation is not authorized, and (3) the quarantine pests of concern.

The plant taxa now regulated because they host various types of plant pests are listed in two parts.

1) Species designated during the first round of action were proposed in 2011 and finalized in 2013 =

2)  Species proposed in 2013 and finally designated on June 19, 2017 =


In summary, the second round of NAPPRA seeks to prevent introduction of the following specific pests by prohibiting imports of their associated plants from most countries. Imports from Canada are often excepted and those from the Netherlands less often.

  • Asian longhorned beetle (ALB, Anoplophora glabripennis) – Celtis, Cercidiphyllum (katsura), Koelreuteria, Tilia
  • Great spruce bark beetle (Dendroctonus micans) – Pseudotsuga
  • Japanese pine sawyer (Monochamus alternatus) – Cedrus
  • Phytophthora kernoviae 17 genera, including Camellia, Fagus, Hedera, Ilex, Leucothoe, Liriodendron, Magnolia, Pieris, Quercus, Rhododendron, Sequoia, Vaccinium
  • Boxwood blight (Puccinia buxi) – Buxus (boxwood)


There are other restrictions on plant imports related to pests, which predate the most recent NAPPRA listing. These include =

  • Acer is already listed on the previous NAPPRA list for all countries except Canada, Netherlands, and New Zealand.
  • Longstanding regulations prohibit the importation of Abies species from all countries except Canada. The genera Larix, Picea, and Pinus were added to the NAPPRA list in the April 2013 NAPPRA notice.
  • Camellia was also listed in 2013 from all countries, except Canada, to prevent introduction of the citrus longhorned beetle (CLB, Anoplophora chinensis); the genus is also regulated for Phytophthora ramorum. The most recent action now adds restrictions because Camellia is also a host of Phytopththora kernoviae. Plants from Canada are exempt because of longstanding “significant trade” volumes.
  • While plants in the genus Cercidiphyllum (katsura) may be imported from the Netherlands – despite the presence in the country of both ALB and CLB – a 2013 Federal Order (DA–2013–18) specifies mitigation actions which exporting countries must take to prevent transport of these insects via trade in this or other genera.
  • Hedera was added to the NAPPRA list via the first round of proposals in April 2013 as a host of CLB. Under the 2013 proposal, the genus is also listed as host of Phytophthora kernoviae.
  • Vaccinium are consistently exported only from Canada and Australia. The genus is listed because it is a host of Phytophthora kernoviae.

As APHIS notes in its explanation in the Federal Register, P. kernoviae has been reported in England, Ireland, and New Zealand; APHIS considers this to be evidence of spread of the pathogen through the global movement of plants. APHIS notes further that the pathogen has a large number of confirmed hosts and there is currently no effective control measure. APHIS does not note that the native range of P. kernoviae is unknown.

APHIS received considerable pushback on its proposal to restrict importation of Callistephus, Chrysanthemum, and Eustoma spp. to prevent introduction of several pathogens, including chrysanthemum stem necrosis virus (CSNV) and chrysanthemum white rust.  In response, APHIS has withdrawn these three genera from the new NAPPRA listing while it conducts a commodity import evaluation document (CIED) for Chrysanthemum.


I have not discussed here NAPPRA as it applies to invasive plants. In April I blogged about the need for APHIS to act. Plants listed because of their invasive potential are posted here =

1) 2013 listing:

2) 2017 listing:

Again, I welcome USDA’s finalization of this second round of regulations and look forward to new proposals.


History of NAPPRA

In December 2004 APHIS published in the Federal Register an Advance Notice of Proposed Rulemaking, or ANPR which outlined a strategy for reducing pest introductions via the “plants for planting” pathway. The strategy had two major steps.

First, the agency would create a temporary holding category for plants suspected of transporting insects or diseases. This would allow APHIS to suspend imports of particular plants, from certain countries, until a full risk assessment was completed.

Second, APHIS would issue regulations establishing a general framework to minimize the presence of pests. Using this, the agency would negotiate country-specific requirements for imported plants, working toward an approach that would rely on “integrated measures” (also called “integrated pest management”).

APHIS formally proposed to create the temporary holding category – the NAPPRA program – in 2009. The regulations were finalized in May 2011 – six and one half years after the intention to take this action was announced in the ANPR. In adopting the NAPPRA rule, APHIS reiterated the need to encourage, but not require, the plant import trade either to rely on low-risk plant materials or to adopt pest-reduction methods.

In July 2011, APHIS published the initial list of species proposed for inclusion in the NAPPRA category.  This list was finalized in April 2013. A second list of species proposed for NAPPRA listing was published in May 2013.

This history – with citations – can be found in chapter 4, “Invasion Pathways”, in my report Fading Forests III, available here.


Meanwhile, here are a few related FAQs about NAPPRA as it is being implemented.


Why does APHIS regulate by genus?

APHIS regulates pests’ hosts at the genus level because when a new species is identified as a host, additional scientific studies often identify other host species within that genus. Therefore, regulating all species within the genus is the preferred course of action until a formal Pest Risk Analysis (PRA) is conducted. Uncertainties are worked out then.


How do these new rules fit into international standards?

APHIS notes in the Federal Register notice that  the “plants for planting” pathway is recognized as posing a high risk  for the introduction of pests. For this reason, the International Plant Protection Convention recommends that countries require a pest risk analysis before allowing importation of a plant taxon from a new country or region.


How long is importation of plants prohibited?

NAPPRA listing does not prohibit the importation of taxa indefinitely. Imports are held up until a pest risk analysis can be conducted to identify appropriate mitigation measures. Furthermore, an importer may apply for a controlled import permit to import small quantities of a prohibited or restricted taxon for developmental purposes.


What is the meaning of “significant trade”?


If a taxon that is a host of a quarantine pest has been imported in ‘‘significant’’ quantities from a specific exporting country, it is not eligible for the NAPPRA prohibition. Currently APHIS defines “significant trade” as the importation of 10 or more plants of a taxon in each of the previous three fiscal years. At the urging of one commenter, APHIS is considering whether to alter that definition by looking at import volumes over three out of five years – although the agency said if it took that action, it would most likely also consider raising the base number of plants from 10 to a higher level.


In the case of “significant trade” in a taxon that is a host of a quarantine pest, APHIS specifies other measures to address the pest risk.


What other protections does APHIS use?

A “Federal order” is used to rapidly take action to prevent the introduction of a quarantine pest, and is generally followed by notice and an opportunity for public comment. This is a separate action from the NAPPRA process.




The Overhaul of Regulations for “Plants for Planting (P4P) (the “Quarantine-37” or “Q-37” regulations) – Will It Also Be Finalized?


Another important APHIS action aimed at improving control over introductions of pests on imported plants has also been unresolved for four years. This is the revision to the agency’s overall plant import regulations, which was also proposed in May 2013. The revision would restructure the current regulations by moving specific restrictions on the importation of taxa from regulations to the Plants for Planting Manual. That transfer would allow specific restrictions to be changed without going through the full public notice and comment process required for amending formal federal regulations. The proposed revision would also add a framework for requiring foreign plant suppliers to implement integrated pest management measures to reduce pest risk. Experts believe that depending on integrated measures will better prevent pest introductions than the current reliance on a visual inspection at the time plants are shipped.


Again, for a history of and rationale for the proposed regulatory change, read chapter 4, “Invasion Pathways”, in my report Fading Forests III, available here.


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.


Plan to Join the Continental Dialogue in Savannah, Georgia, in November 2017!

Spread of laurel wilt since 2003; source: USFS

Redbay mortality, Claxton, GA 2009

photo by Scott Cameron

The southeastern states have been invaded by a smaller number of non-native, tree-killing insects and pathogens than some other regions (see map below). But among these are highly damaging pests that show just how vulnerable this area’s native species and forests are, e.g., chestnut blight, laurel wilt, hemlock woolly adelgid, balsam woolly adelgid, and now emerald ash borer (all described here).

Join the Continental Dialogue on Non-Native Forest Insects and Diseases at its annual meeting in Savannah, GA, November 9 & 10, 2017 to learn about the issues outlined below and to build relationships to sustain action. The meeting will be in conjunction with the Annual Gypsy Moth Review, so we will also discuss the most recent developments pertaining to European and Asian gypsy moths. Visit to see the agenda and registration information (both to be posted soon).

The Southeast is at high risk for greater damage because:

  • The Port of Savannah is already the largest container port on the East Coast. Now, it moves 20,000 shipping containers per day and it is adding infrastructure to increase this volume.

Most of these containers – and their accompanying wood packaging material (for more on the risk from wood packaging, see my blog from the end of January; and fact sheets here) quickly move to distribution centers or their ultimate destinations – throughout the Southeast but as far away as Chicago. However, the port has storage for millions of containers on paved container yards that total 1,200 acres.  The storage yards are close to mixed forests.

Trees across road from stored containers at Port of Savannah;  photo by F.T. Campbell

More of these ships and containers will come directly from Asia – the major source of our most damaging invaders — now that the Panama Canal has been widened. When I visited the port in mid-May, the largest container ship ever to visit the U.S. East Coast was being unloaded – and re-loaded simultaneously!  The “Cosco Development” carries 13,200 TEUs (twenty-foot equivalent containers).

Unloading “Cosco Development” at Port of Savannah; photo F.T. Campbell

  • The sudden oak death pathogen (Phytophthora ramorum) has been found in streams and ponds in several southeastern states – Alabama, Florida, Georgia, Mississippi, North Carolina, South Carolina, and Texas. Positive samples were drawn from three streams in Alabama and one stream in Mississippi in 2016. Most of these water bodies are near nurseries that had received infested plants from West Coast suppliers. In addition, infested plants have been detected recently in nurseries or landscape plantings in Louisiana, Texas, and Virginia, as well as in other states farther north [link to 2015 blog]. These infested plants have been removed. What is the current scientific thinking about the implications of these detections? Last I heard, scientists thought the pathogen cannot survive in water; it needs some plant material. Yet scientists have not found on-going infestations on plants along the streams and ponds. For more information on SOD, visit


  • Over recent decades, a half dozen non-native insects that attack pine trees have become established in the continental United States. These include the Sirex woodwasp, common pine shoot beetle, golden (or red) haired pine bark beetle (Hylurgus ligniperda), Mediterranean pine shoot beetle (Orthotomicus erosus) — all described here. The mountain pine beetle (Dendroctonus ponderosae) has spread east of the Rocky Mountains and might eventually reach pine forests of the Midwest and East.


While none of these (other than the mountain pine beetle) has yet caused very much damage where they are established, should we continue to assume that they will not cause damage once they reach the “pine basket” of the Southeast? Even if plantations can be managed to minimize risk, what are the implications for natural pine forests so important to the ecosystems and protected areas of the region?


It is unclear whether the fact that the Secretary of Agriculture, Sonny Perdue, is a former governor of Georgia with a record of support for forestry will raise attention to some of these issues.  As you might remember (see my blog from March 28th), apparently no senators raised invasive pest issues during Secretary Perdue’s confirmation.

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.


USDA needs to utilize the NAPPRA Process to Prevent New Introductions



America’s imports of plants to serve various purposes have been a major pathway for introduction of invasive species – both some of the plant species imported intentionally and insects and pathogens associated with those plant imports.

Examples of the former include numerous forage grasses, Callery pear (just past its peak bloom here in the MidAtlantic region), autumn and Russian olive, kudzu, shrub and vining euonymus, iceplant, … [see my blogs from January 2016  and March 2016 for more about invasive plants].

Pests introduced on imported plants range from chestnut blight and white pine blister rust at the beginning of the 20th Century to sudden oak death in the 1980s and probably the polyphagous and Kuroshio shot hole borers more recently. All these pests are described briefly here.

For lengthy discussions of the “plants for planting” pathway of introduction for insects and pathogens, read my report Fading Forests III available here; or the Liebhold et al. article referenced at the end of this blog.

A new article by Barry Yeoman describes the effects on wildlife species of these introductions. “Going Native: Exotic garden plants can wreak unexpected havoc with indigenous species and ecosystems” can be read here .

dogwood anthracnose; Robert L. Anderson. courtesy of

Yeoman notes that birds and other wildlife that feed on the fruits of native dogwood can’t utilize the fruits of the introduced kousa dogwood. Furthermore, native dogwoods have been decimated by dogwood anthracnose  – probably introduced on imports of kousa dogwood! Another pest example cited by Yeoman is the loss of eastern hemlock to hemlock woolly adelgid.

Yeoman goes on to report the impacts on wildlife species of such invasive plant species as Japanese knotweed, autumn olive, Chinese tallowtree, and Japanese barberry. The last is even linked to higher populations of the ticks that spread Lyme disease.

Yeoman writes that the United States has “a feeble system of regulating garden imports. Each new species is presumed harmless until proven otherwise—and by the time a verdict arrives, the harm is often beyond repair.”  He criticizes our government’s reliance on a modified blacklist system – a short list of “noxious weeds” .  This approach allows potential invaders to enter the country without scientific evaluation.


As Yeoman describes in the article, the noxious weed list is supplemented by a small “graylist” of plant species that could potentially cause harm and are temporarily barred until they can be evaluated. Yeoman does not describe the program under which this “graylist” has been created. In May 2011, USDA APHIS  created a temporary holding category, called “Not Authorized (for importation) Pending Pest Risk Analysis,” or NAPPRA. With this authority, APHIS may temporarily prohibit import of certain types of plants, from specific countries of origin, that it considers to pose a particular risk. The risk might be invasiveness of the plant species itself, or pests associated with the plants. The temporary prohibition on imports of those species gives APHIS time to complete a pest risk analysis and then enact appropriate safeguards to ensure that the imported plants will not be invasive or present as low a pest risk as possible.


For a more complete description of the graylist process, called NAPPRA, read Fading Forests III here .


The NAPPRA process holds the promise of providing substantial protection by curtailing imports of high-risk plants.  However, its implementation has stalled. APHIS last proposed additions to the list of plant species prohibited entry temporarily in May 2013 – almost four years ago!  APHIS should revive the NAPPRA process and utilize prompt listing of plants under this authority to minimize the risk that new pests will be introduced.



Liebhold, A.M., E.G. Brockerhoff, L.J. Garrett, J.L. Parke, and K.O. Britton. 2012. Live Plant Imports: the Major Pathway for Forest Insect and Pathogen Invasions of the US.


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.


Posted by Faith Campbell

Pest threat to West Coast confirmed – authorities should respond to this information by taking protective measures

 Numbers of non-native pests in counties of the 49 continental states; Map prepared by Andrew Liebhold, USFS in 2014. More recent introductions are not represented; nor are insects native to some part of North America

Currently, the Northeast and Midwest have the highest number of non-native, tree-killing insect and pathogen species (see map above). However, Pacific coast states have two-thirds the numbers of pest species of the Northeast – and are catching up. Two articles modeling the likelihood of new pest introductions point to the particular vulnerability of the Pacific Coast states – especially California – to pest introductions from Asia.


Koch et al. 2011 (see reference at the end of the blog) utilized various sources of information about volumes of imports likely to be associated with wood-boring pests — stone; raw wood and wood products (including crates & pallets); metals; non-metallic minerals; auto parts; etc. From this, the authors estimated both a nationwide establishment rate of wood-boring forest insect species and the likelihood that such insects might establish at more than 3,000 urban areas in the contiguous U.S. While their estimate was based on 2010 imports, they also projected rates for 2020.


See my blog from March 10  for various scientists’ estimates of  the overall, nationwide rate of introduction.  Koch et al. estimated the nation-wide introduction rate at between 0.6 and 1.89 forest insects and pathogen species per year for the period 2001–2010 and 0.36 and 1.7 species per year for 2011–2020.  In other words, we should expect a new alien forest insect species to become established somewhere in the United States every 2–3 years. If one-tenth of these new introductions turn out to cause significant damage, then we can expect a “significant” new forest pest every 5–6 years.


Pacific coast states – especially California – are at highest risk. 

Koch et al. evaluated the introduction risk for 3,126 urban areas across the country. The metropolitan area with the highest risk is Los Angeles–Long Beach–Santa Ana, California. For both 2010 and 2020, the predicted rates for a new pest establishing there is every 4–5 years.


Looking ahead to 2020, the situation worsens for three California metro areas – Los Angeles–Long Beach–Santa Ana; San Diego; and Riverside-San Bernardino. At San Francisco-Oakland, the predicted establishment rates remain steady. Most of the rest of the top 25 urban areas show decreases in establishment rate between 2010 and 2020.


This rising risk to California urban areas is driven by the growth of imports from Asia. For the four California urban areas, the establishment rate of Asian species is projected to increase 6–8% between 2010 and 2020. The Los Angeles–Long Beach–Santa Ana area could potentially expect the establishment of an alien forest insect species originating specifically from Asia alone (not the entire world) every 4–5 years.

[The polyphagous and Kuroshio shot hole borers are examples of recently introduced pests from Asia.  Both are described, inter alia, here; a distribution map for PSHB is available here.]

Koch et al. note that the Los Angeles metropolitan area has a dense human population with corresponding high demand for goods and materials, so a substantial proportion of imports clearing the port remains in the areas.  Furthermore, widespread planting of non-native plants provides a range of potential hosts that can support invaders that would not otherwise become successfully established.


A second source also indicates a heightened risk to Pacific Coast states. Yemshanof et al. used similar modeling techniques to evaluate the risk of tree pest introductions to Canada … and to the U.S. in the form of transshipped goods.  (See my earlier blog.)


The Yemshanof et al. model showed that 8% of all forest pests introduced to the U.S. on imported wood or wood packaging — as estimated by Koch et al. — would come through goods transshipped through Canada. The risk is highest to the Pacific Coast states since they are the most likely to receive Asian goods transiting through Canada.


Note that the phytosanitary agencies in both the U.S. and Canada proposed in 2010 that wood packaging originating in one of the countries and shipped to the other be required to meet the international regulations under ISPM#15. However, APHIS was unable to adopt this regulation under the Obama Administration, and such an action seems even less likely under the Trump Administration. Canada is unlikely to adopt the new rules without a coordinated U.S. action.


Southern California also imports lots of plants – another pathway for pest introductions.


Koch et al. suggest that authorities use these models to prioritize border control efforts (e.g., commodity inspections), post-border surveillance, and rapid-response measures.  I see some problems with these suggestions.  First, enhanced commodity inspections are not likely to measurably diminish the risk of introduction to the region. Second, rapid-response measures require both increased funds – which are expected to decrease; and political will. I have blogged several times about California’s decisions to not implement official, regulatory responses to recently detected pests.


Instead, people in the region should actively build alliances and press their regional political leaders – governors, mayors, senators, members of Congress – to demand that the U.S. Department of Agriculture and the Congress adopt policies that will strengthen protection for the region’s trees.


New pest detected in California!


California authorities have detected a new woodboring beetle – the olive wood borer (Phloeotribus scarabaeoides). It was detected in an olive tree in a grape vineyard in Riverside County. This is the first detection of the species in the Western Hemisphere. Known or suspected hosts include several trees in the olive family (Oleaceae), including olive trees, privet, ash, and common lilac; as well as oleander (Apocynaceae).


Since this new pest is native to the Mediterranean region, it does not appear to be an example of the risk to California from Asia …  The source (Diagnostic Network News; see below) does not speculate on the pathway by which the introduction occurred.



What Can We Do?


Ask your state’s Governor to

  • Communicate to the USDA Secretary the need to amend policies & regulations

(Coordinate this effort with governors of other states.)

  • Put forest pest issue on the agenda of National Governors’ Association
  • Ask your state’s Congressional delegation to pressure USDA Secretary to amend policies and regulations
  • Communicate concern about these pests to the media — and propose solutions.


Ask your state’s agricultural and forestry agency heads to

  • Ask their national associations to support proposals to USDA Secretary & Congress. These associations include
    • National Association of State Departments of Agriculture (NASDA)
    • National Association of State Foresters (NASF) or its Western regional group, the Council of Western State Foresters
  • Communicate to the media both the agency’s concern about tree pest threats and proposed solutions.


We can also act directly.

  • Ask mayors and officials of affected towns and counties to
  • Push proposals at regional or National Conference of Mayors or National Association of Counties
  • Instruct local forestry staff to seek support of local citizen tree care associations, regional and national associations of arborists, Arbor Day & “Tree City” organizations, Sustainable Urban Forest Coalition, etc.
  • Reach out to local media with a message that includes descriptions of policy actions intended to protect trees — not just damage caused by the pests
  • Ask stakeholder organizations of which you are a member to speak up on the issue and support proposed solutions; e.g.,
    • Professional/scientific associations
    • Wood products industry
    • Forest landowners
    • Environmental NGOs
    • Urban tree advocacy & support organizations


  • Encourage like-minded colleagues in other states to press the agenda with their state & federal political players, agencies, & media.
  • Communicate to the media both your concern about tree pest threats and proposed solutions.


What Specific Actions Should We Suggest be Taken?

I suggest a coordinated package.  However, you might feel more comfortable selecting a few to address each time you communicate with a policymaker. Choose those on which you have the most expertise; or that you think will have the greatest impact.

  • Make specific proposals, not vague ideas (see below for suggestions)
  • Always include information about how the pests arrive/spread (pathways such as imports of crates & pallets, or woody plants for ornamental horticulture) and what we can do to clean up those pathways  (Don’t just describe the “freak of the week”)
  • Always point out that the burden of pest-related losses and costs falls on ordinary people and their communities. (Aukema et al. 2011 provides backup for this at the national level; try to get information about your state or city.)
  • We need to restore a sense of crisis to prompt action – but not leave people feeling helpless! We need also to bolster understanding that we have been and can again be successful in combatting tree pests.


Specific actions that will reduce risk that pests pose to our trees:

  • Importers switch from packaging made from solid wood (e.g., boards and 4”x4”s) to packaging made from other materials, e.g., particle boards, plastic, metal …
  • Persuade APHIS to initiate a rulemaking to require importers to make the shift. This can be done – although international trade agreements require preparation of a risk assessment that justifies the action because it addresses an identified risk (see my earlier blogs about wood packaging).
  • Create voluntary certification programs and persuade major importers to join them. One option is to incorporate non-wood packaging into the Department of Homeland Security Bureau of Customs and Border Protection’s (CBP) existing Customs-Trade Partnership Against terrorism (C-TPAT) program.


  • Tighten enforcement by penalizing shipments in packaging that does not comply with the current regulations
  • Persuade CBP and/or USDA to end current policy under which no financial penalty is imposed until a specific importer has been caught five times in a single year with non-compliant wood packaging. APHIS has plenty of authority to penalize violators under the Plant Protection Act [U.S.C. §7734 (b) (1)].
  • Restrict imports of woody plants that are more likely to transport pests that threaten our trees
  • In 2011, APHIS adopted regulations giving it the power to temporarily prohibit importation of designated high-risk plants until the agency has carried out a risk assessment and implemented stronger phytosanitary measures to address those risks. Plants deserving such additional scrutiny can be declared “not authorized for importation pending pest risk assessment,” or “NAPPRA”. A list of plants posing a heightened risk was proposed nearly 4 years ago, but it has not been finalized – so imports continue. APHIS should revive the NAPPRA process and utilize prompt listing of plants under this authority to minimize the risk that new pests will be introduced.
  • APHIS should finalize amendments to the “Q-37” regulation (proposed nearly 4 years ago) that would establish APHIS’ authority to require foreign suppliers to implement integrated programs to minimize pest risk. Once this regulation is finalized, APHIS could begin negotiating agreements with individual countries to adopt systems intended to ensure pest-free status of those plant types, species, and origins currently considered to pose a medium to high risk.


  • Strengthen early detection/rapid response programs by
  • Providing adequate funds to federal & state detection and rapid response programs. The funds must be available for the length of the eradication program – often a decade or more.
  • Better coordinate APHIS, USFS, state, & tribal surveillance programs.
  • Engage tree professionals & citizen scientists more effectively in surveillance programs.





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


Western Plant Diagnostic Network First Detector News. Winter 2017. Volume 10, Number 1.


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


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

Posted by Faith Campbell

Likely Next Secretary of Agriculture Not Asked About Phytosanitary Issues on March 23, 2017

Secretary of Agriculture nominee Sonny Perdue

Former Governor of Georgia Sonny Perdue was President Trump’s last pick for his cabinet. His long-delayed confirmation hearing took place before the Senate Committee on Agriculture, Nutrition, and Forestry on March 23, with at least 18 of the 21 members present for at least some of the time. He’s likely to be confirmed easily, given support from 700 agricultural organizations and six former USDA secretaries. However, final approval could take several weeks, given the time needed to answer senators’ follow-up written questions and a looming congressional recess.

In his opening statement, the nominee named four goals: creating jobs, making customer service a priority, keeping food safe for consumers, and ensuring stewardship of American lands. (Mr. Perdue’s statement and video of the full hearing are on the Committee’s website.)


The hearing was friendly – except to the President’s proposed budget, which calls for a 21 percent cut in USDA’s discretionary spending. Ranking Minority Member Debbie Stabenow (D-MI) said the budget makes it clear that “rural America is an afterthought.” But Chair Pat Roberts (R-KS) and others noted that “the President proposes and Congress disposes,” with a nod down the table to Sen. John Hoeven (R-ND), who chairs the Senate Appropriations Committee’s agriculture subcommittee. Sens. Thad Cochran (R-MS), Mitch McConnell (R-KY), and Patrick Leahy (D-VT) — each with considerable seniority — serve on the same subcommittee.


Phytosanitary policy did not come up — although CISP and others provided lists of potential questions on the topic to several senators. Sen. Amy Klobuchar (D-MN) did ask how to stop the spread of avian influenza, detected in Tennessee, Wisconsin, and Alabama. Gov. Perdue seemed confident, saying U.S. poultry exports are critical and we’d learned to respond quickly. (Four days later the disease was detected in chickens in Georgia.)


Few USDA agencies were mentioned by name. The Animal and Plant Health Inspection Service (APHIS) was among those not mentioned. In response to questions, Gov. Perdue did voice support for “critical” research and extension done by the Natural Resource Conservation Service and said, in defense of the National Agricultural Statistical Service (NASS), that farmers need “independent, trusted sources” of information. Sen. John Thune (R-SD) asked about the potential of pathogen-laden meat imports from Brazil. Perdue noted that the Food Safety and Inspection Service “wants to go to” 100% inspection (a policy announced March 22) but a beef embargo would risk retaliation.


Mostly, specific programs were named only if they were targeted by the President for cuts (like NASS). Efforts to clean up agricultural runoff that pollutes the Chesapeake Bay and the Great Lakes; work to stem rural opioid addiction; and initiatives for rural clean water all fall into this group.


Only the U.S. Forest Service received more than passing attention. Its management of national forests was criticized. Several senators noted the crisis in funding fire-fighting. Forests, Gov. Perdue said, provide “opportunities clothed in challenges,” e.g., to implement best management practices and be better neighbors. Sen. Steve Daines (R-MT) urged him to restore active management of forests, as well as to limit litigation by “extremist groups.” Perdue sympathized.

Several themes came up repeatedly:


  • The importance of foreign trade. Chair Roberts wants agriculture at the top of priorities for the new White House National Trade Council. Gov. Perdue has already met with the U.S. Trade Representative and Secretary of Commerce and aims to “sell [the country’s] bounty” in expanding markets.


  • The need for the secretary to be an unapologetic advocate for agriculture within the Administration. Gov. Perdue promised to be a “tireless salesman.” Hope that Perdue would support ideas proposed for the 2018 Farm Bill. These include expanding crop insurance for growers of specialty crops and the dairy industry; ensuring immigration/visa policy that supports year-round access to labor for dairy farms; providing summer nutrition programs for students.


  • Changing regulations that were called, variously, costly, hard-to-understand, or very onerous. As secretary, Perdue would “incentivize producers” to conserve without “onerous prescriptive regulations” (like those on wetlands; he has met with the new EPA Administrator).


  • Members’ requests that he visit their states — in some cases for public meetings on the new Farm Bill.


Generally, Mr. Perdue was agreeable — e.g., toward a stronger renewable fuel standard and better rural broadband access — or at least found Members’ suggestions “intriguing”. He promised to provide resources to help with the new farm bill and to further implement the 2014 one, either more fully (as Sen. Klobuchar requested) or more flexibly (as Sen. Thune did). Gov. Perdue confessed “some concern” about proposed budget cuts, for example, to agricultural research, organic agriculture, telemedicine, and nutrition programs — a list supplied by Sen. Stabenow. He cited his experience working within tight budgets in Georgia, though, and expects to do the same at USDA. He said that he was a “facts-based, data-based decision-maker.”


Gov. Perdue grew up on a dairy farm, is a veterinarian, and runs several agribusinesses. The latter got him in trouble, as Georgia governor, with the state’s ethics commission. He has agreed to put his businesses in trust if confirmed. These concerns did not come up in the hearing. Nor did his controversial views on climate change, although Sen. Patrick Leahy (D-VT) noted the connection between fire and climate change and said climate change must be addressed. One person was ejected from the hearing after protesting animal agriculture.



Chair Roberts (R-KS); Cochran (R-MS); Boozman (R-AK); Hoeven (R-ND); Ernst (R-IA); Thune (R-SD); Daines (R-MT); Perdue (R-GA – the nominee’s cousin); Strange (R-AL).

Ranking Member Stabenow (D-MI); Leahy (D-VT); Klobuchar (D-MN); Brown (D-OH); Bennet (D-CO); Gillibrand (D-NY); Donnelly (D-IN); Heitkamp (D-ND); Van Hollen (D-MD).


Our comment:


We are disappointed that no one asked a single question about introduced pests or weeds. Nine of the senators present are from states already suffering severe tree mortality caused by the emerald ash borer; four more are from states that will soon see significant losses to that pest. All are from states in which invasive plants are often said to threaten agricultural production and/or natural resources.

Perhaps some questions will be put to Mr. Perdue in writing.


The combination of silence on phytosanitary issues and emphasis on the importance of trade seems to promise a continuation of imbalances that favor trade promotion at the expense of vigorous phytosanitary measures. If USDA leadership is focused on promoting export markets for U.S. agricultural producers, it will be difficult to persuade the agency to adopt and enforce effective tools to prevent pest introductions.



For more information:

DelReal, J.A. 2017. “Senators press Perdue on USDA budget. The Washington Post , March 24, p. A10.

Sheinin, A.G., “Bird flu found in Georgia chicken flock.” Atlanta Journal Constitution. March 27, 2017.–regional-govt–politics/bird-flu-found-georgia-chicken-flock/DGgBp1sUhctO6JLDLLyIFJ/

Sullivan, B.D., Sonny Perdue gets friendly reception during Agriculture secretary hearing, USA TODAY March 23, 2017.

U.S. Department of Agriculture, “USDA on tainted Brazilian meat: none has entered U.S., 100 percent re-inspection instituted.” Press release, March 22, 2017.



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.


Posted by Phyllis Windle and Faith Campbell