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


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

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

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

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

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

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

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

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

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

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


What Should We Do?

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

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

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

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

Expect to hear from me often in the coming year!



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

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

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


Posted by Faith Campbell

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.


Invasive insects cause tens of billions in damage


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

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

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

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

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

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

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

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



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

Posted by Faith Campbell

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.

What the new President & Congress Can Do re: Invasive Species

 White House


A new President and Congress take office in January.  And outgoing President Obama recently amended the Executive Order on invasive species.

What might the new leaders do to improve America’s invasive species programs?

Here are a group of actions that I think would improve programs significantly:

  • amend the Lacey Act to strengthen controls over introduction and spread of invasive animals and animal diseases;
  • raise the political profile of invasive species issues by holding more frequent oversight hearings;
  • increase funding for invasive species prevention, containment, and control programs;
  • support proposals to amend the 2019 Farm Bill to strengthen on-the-ground programs, policies, and research aimed at minimizing invasive species introduction, spread, and damage;
  • during the confirmation process, Senators should ask President Trump’s nominees to leadership positions in the Departments of Agriculture and Interior about how they will address invasive species challenges.

Do we need new legislation mandating that federal land-managing agencies do X or Y with regard to invasive species? This was the focus of a hearing in May at which I testified.

Federal land-managing agencies are already authorized and – in some cases required – to act to control invasive species on lands and waters under their jurisdiction.  Some of the existing statutes even authorize the agencies to apply fees paid by people who use the public lands for some purpose (e.g., livestock grazing, recreation) to management of invasive species.

Most of the statutes authorizing invasive species management incorporate that activity into the agency’s broader management goals for protection of wildlife, habitat, natural resources, historic or cultural sites, etc.  For example, the USFS Manual §2900 lists 21 laws and 6 regulations or policies that govern the USFS’ management of invasive species.  Some of these laws apply to all federal land-managing agencies, including:

  • Endangered Species Act (ESA) of 1973 (16 U.S.C. §§1531 et seq.)
  • Surface Mining Control and Reclamation Act of 1977 (30 U.S.C. 1201, 1201 (note), 1236, 1272, 1305). §515
  • North American Wetland Conservation Act 1989 (16 U.S.C. 4401 (note), 4401-4413, 16 U.S.C. 669b (note)). §9 [U.S.C. 4408]
  • Sikes Act (Fish and Wildlife Conservation) of September 15, 1960 (16 U.S.C. 670g-670l, 670o, P.L. 86-797), as amended. §201
  • National Historic Preservation Act of 1966 [16 U.S.C. §§470 et seq.]
  • Wilderness Act of 1964 (16 U.S.C. §§1131 et seq.

Other statutes apply only to resource management authorities of the USDA Forest Service; these include:

  • Organic Administration Act of 1897 (16 U.S.C. §§ 473 et seq.).
  • Fish and Wildlife Coordination Act (16 U.S.C. § 661 et seq.).
  • Knutson-Vandenberg Act of June 9, 1930 (16 U.S.C. 576, 576a-576b). §3 [16 U.S.C. 576b]
  • Bankhead-Jones Farm Tenant Act of 1937 (7 U.S.C. §§1010 et seq.)
  • Anderson-Mansfield Reforestation and Revegetation Act of October 11, 1949 (16 U.S.C. 581j (note), 581j, 581k)
  • Multiple-Use Sustained-Yield Act of 1960 (16 U.S.C. §§528 et seq.)
  • Forest and Rangeland Renewable Resources Planning Act (RPA) of 1974 as amended by the National Forest Management Act (NFMA) of 1976. §6
  • International Forestry Cooperation Act of 1990 (16 U.S.C. § 4501)
  • Healthy Forests Restoration Act of 2003 (H.R. 1904), [16 U.S.C. 6501-6502, 6511-18, 6541-42, 6571-78]
  • Wyden Amendment (P.L. 109-54, Section 434).
For brief descriptions of all these statutes, see the references and links at the end of this blog posting.

Advocates have tried before to legislate a specific requirement that federal agencies combat invasive species.  The Federal Noxious Weed Act of 1974 (7 U.S.C. § 2801 note; 7 U.S.C. § 2814) was amended in 1990 to add §15, “Management of Undesirable Plants on Federal Lands”.  This section requires each federal agency to

1) designate an office or person adequately trained to develop and coordinate an undesirable plants management program for control of undesirable plants on federal lands under the agency’s jurisdiction, and

2) establish and adequately fund an undesirable plants management program through the agency’s budgetary process,

3) complete and implement cooperative agreements with state agencies regarding the management of undesirable plant species on federal lands, and

4) establish integrated management systems to control or contain undesirable plant species targeted under cooperative agreements.

This approach hasn’t worked – no one is satisfied by the federal agencies’ “weed” management efforts.



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

I am not saying that the principal statutes governing invasive species management could not be improved.  As noted above, several proposals have been put forward to strengthen laws which are the foundation for preventing introduction of invasive species.  I will blog about specific proposals in the new year.



USFS Invasive Species Manual

ANSTF/NISC report “Federal Policy Options Addressing the Movement of Aquatic Invasive Species Onto and Off of Federal Lands and Waters. 2015.  Committee on the Movement of Aquatic Invasive Species both onto and off of Federal Lands and Waters.

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.

Statement of the Center for Invasive Species Prevention on withdrawing its proposal to the U.S. Fish and Wildlife Service to add the red swamp crayfish to the Lacey Act for further analysis


On September 26, 2016, the Center for Invasive Species Prevention (CISP) petitioned the U.S. Fish and Wildlife Service (USFWS) to add 43 species to those regulated under the Lacey Act. Among these species was the red swamp crayfish (Procambarus clarkia). We now plan to withdraw and reconsider that species after we do more analysis.

We recognize that this crayfish species has major economic value. It is an important part of peoples’ livelihoods in Louisiana in particular. By no means do we want anyone in that business to feel threatened by the Petition.

Right now, the CISP Petition has no official status within the Federal government. It has not been published in the Federal Register nor has the USFWS indicated any intent to make it an official agency proposal. Even if it did, such a listing would not affect collecting, harvesting, rearing or selling crawfish directly within Louisiana or within other range States.

We would like to clear up some other confusion. It is true that the Lacey Act is used to prevent first-time imports of non-native “injurious wildlife” into the United States. The law has other provisions, though, that help prevent additional introductions of damaging species already in the country, that help stop harmful species’ interstate spread, and that apply to native species invading outside of their native ranges. These latter aspects can provide nationwide protection at a time when individual State’s laws are uneven. Populations of the red swamp crayfish are turning up in the wild. One can see how quickly it has become a nationwide problem in the wild on the animated map at the U.S. Geological Survey’s website. Approximately a dozen states have responded with their own prohibitions or other regulations.

We do think it is important to set a precedent that USFWS acts, in some way, on all species it determines to be of highest risk of invasiveness. Our Petition aimed to get this ball rolling. Much further analysis and public comment would go into any eventual decisions that USFWS makes on individual species. It could leave regulation of species in widespread trade to individual States.  On the red swamp crayfish, CISP will withdraw that species from our Petition and reconsider what the best options are. Then we will consider whether a new Petition tailored to that species is warranted.


posted by Peter Jenkins

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 uncivil or inflammatory.

Support Effort to Declare UN “International Year of Plant Health”


Officials who carry out plant health programs around the world are trying to build public understanding and support for such programs by organizing an “International Year of Plant Health”. Such “international years” are designated by the United Nations General Assembly – so – as you can imagine – years of planning go into the effort.

So far, the proposal has been approved by the Council of Agricultural Ministers and will be considered by the Conference of the UN Food and Agriculture Organization in June 2017. If approved by the FAO, the proposal will then be put to the full United Nations by sponsoring nations’ diplomats.  The General Assembly meeting in 2018 would consider the proposal – assuming FAO does forward it.

The goal of the proposed Year is to persuade decision-makers and the public that protecting plants by preventing and containing pests is an essential foundation for countries’ efforts to achieve food security, economic development, and environmental protection. Organizers also want people to know that plant protection is also a necessary component of policies to facilitate trade.

The events associated with the “International Year of Plant Health” will recognize plant health disciplines and the many people and organizations who contribute at the global, regional and national levels. It is not intended to celebrate specifically the International Plant Protection Convention, or the standards and other measures it has adopted.

Plant health professionals are concerned that funds and other resources dedicated to plant protection services are shrinking despite the growing threat to agricultural and natural resources from the spread of pests. Without more attention, they fear that resources will fall even farther behind the need as agencies confront demands from other global challenges. They intend to make the case that healthy plants help solve — rather than compete with – such other big problems as climate change, changing migration patterns, biosecurity concerns, and economic development.

The proponents specific objectives are to:

  1. Raise awareness among political decision makers at global, regional, and national levels.
  2. Build up plant health efforts and resources at all levels to better match growing needs linked to increasing trade and the new pest risks caused by climate change.
  3. Educate the broader public so it better understands the importance of protecting plant health.
  4. Enhance dialogue and stakeholder involvement in plant health.
  5. Increase information about the state of plant protection in the world.
  6. Promote partnerships on national, regional, and global levels.

It is hoped that success in raising awareness and understanding will result in sustainable funding of national plant health systems that will, in turn, enable

  • Improved capacity to take on more plant health related projects and programs
  • More effective collaboration and solutions at the global level
  • Better plant health situation in all countries.

I assume that readers of this blog are stakeholders in the global plant protection network. Most of you are professionally engaged in forest or nature conservation (perhaps through research), or are active conservation advocates. Some of you might be affiliated with trade and grower associations. Please consider how you can help educate political decision makers about the importance of protecting plants from non-native organisms that potentially threaten native ecosystems or agricultural and horticultural production. The first task is to ensure that the incoming Secretary of Agriculture actively supports the proposal both among his colleagues (e.g., with the Department of State) and at the FAO Conference in June. Please use your contacts in the government – including the Congress – and with other stakeholders to promote the idea.

Assuming that the International Year of Plant Health is approved, there will be many opportunities to lead or collaborate in the planned outreach efforts. Our engagement might help shape the message. For example, we need to ensure attention to the many challenges currently hindering plant health protection,  as discussed in my blogs and in numerous peer-reviewed articles and reports. Also, we need to make certain that the environmental and biodiversity aspects of plant protection are prominent among considerations.

And if the Year is not approved?  In my mind, that action would prove even more that we need to educate those who do not yet see why healthy trees and other plants matter!

Let me know what you think we might do – by sending me an email using the “contact us” button. Together, we can use this proposal to join coalitions with the goal of promoting stronger, more effective protection for our forests and other natural resources!


Posed 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 uncivil or inflammatory.