funding – Page 2 – Center for Invasive Species Prevention

Support House & Senate bills to Enhance Response to Forest Pests

white ash: a species that might be restored under the programs envisioned in the proposed bills

Bills have been introduced into both the House and Senate to enhance USDA APHIS and Forest Service programs intended to curtail introduction and spread of non-native forest pests and disease and – especially – programs aimed at restoring pest-decimated trees to the forest.

The House bill is H.R. 3174; it was introduced by Reps. Becca Balint (VT).

The Senate bill is S. 1238; it was introduced by Senators Peter Welch (VT), Mike Braun (IN), and Maggie Hassen (NH). [Both senators Welch and Braun are on the Agriculture Committee – which will write the bill.]

CISP hopes that the contents of these two bills will be incorporated in the Farm Bill that Congress is expected to adopt this year or next. The proposals have the support of the Forests in the Farm Bill coalition. [Unfortunately, neither the “Consolidated Recommendations” nor “Summarized Recommendations appears to be posted on the internet at present.]

In the last Congress, a nearly identical bill introduced by then-Representative Peter Welch was endorsed by the organizations listed below. We hope they will endorse the new bills now! If you are a member of one of these organizations, please ask them to do so.

Organizations that endorsed the previous bill: Vermont Woodlands Association, American Forest Foundation, Center for Invasive Species Prevention, Reduce Risk from Invasive Species Coalition, National Woodland Owners Association (NWOA), National Association of State Foresters (NASF), The Society of American Foresters (SAF), the North American Invasive Species Management Association (NAISMA), the Ecological Society of America, Entomological Society of America, a broad group of university professors and scientists, The Nature Conservancy (TNC) Vermont, Audubon Vermont, the Massachusetts Forest Alliance, the New Hampshire Timberland Owners Association, the Maine Woodland Owners Association, and the Pennsylvania Forestry Association.

I seek your help in generating support for incorporating these proposals into the 2023 Farm Bill. Please urge your representative and senators to co-sponsor the bills or otherwise support that action.

beech in a breeding experiment at The Holden Arboretum; photo by Jennifer Koch

Key points of the two bills:

They strengthen APHIS’ access to emergency funds. APHIS has had the authority to access emergency funds from the Commodity Credit Corporation since 2000. However, the Office of Management and Budget has often blocked its requests. See § 2, of the bills, EMERGENCY AUTHORITY WITH RESPECT TO INVASIVE SPECIES.
It creates two separate but related grant programs.
- The first grant program – in § 3. FOREST RECLAMATION GRANTS – funds research addressing specific questions impeding the recovery of tree species that are native to the US and have suffered severe levels of mortality caused by non-native plant pests or noxious weeds.
- The second grant program – in § 4. FOREST RESTORATION IMPLEMENTATION GRANTS – funds implementation of projects to restore these pest-decimated tree species to the forest. These projects must be part of a forest restoration strategy that incorporates a majority of the following components:

(1) Collection and conservation of native tree genetic material.

(2) Production of propagules of the target tree species in numbers sufficient for landscape-scale restoration.

(3) Preparation of planting sites in the target tree species’ former habitats.

(4) Planting of native tree seedlings.

(5) Post-planting maintenance of native trees.

§ 5 states that the absence of a national policy on addressing nonnative forest pests has resulted in their receiving a low priority within all Federal agencies. It then mandates a study to analyze agencies’ available resources, raise the issue’s priority, and improve coordination among agencies. This study is to be carried out by an independent institution, for example the National Academy of Sciences. The authors are to consult with specialists in entomology, genetics, forest pathology, tree breeding, forest and urban ecology, and invasive species management.
Funding for all three action components – the emergency response and both grant programs – would come from the Commodity Credit Corporation, so it would not be subject to the vagaries of annual appropriations bills.

Forest Restoration Alliance volunteers potting hemlock seedlings; photo provided by Fred Hains

Entities which could apply for the research grants (§ 3 of the bills) include Federal agencies; State cooperative institutions; academic institutions offering degrees in the study of food, forestry, and agricultural sciences; and non-profit organizations exempt from taxes under §501(c)(3) of the tax code. Types of research funded could include:

‘‘(A) biocontrol of nonnative pests & diseases or noxious weeds severely damaging native tree species [the bill does not specify, but Project CAPTURE identifies many qualifying species; see also my earlier blog];

‘‘(B) exploration of genetic manipulation of the plant pests or noxious weeds;

‘‘(C) enhancement of pest-resistance mechanisms of hosts; and

‘‘(D) development of other strategies for restoring individual tree species.

The maximum amount of such grants is $400,000 per year.

Entities which could apply for the implementation grants (§ 4 of the bills) include a cooperating forestry school; a land-grant college or university; a State agricultural experimental station; a 501(c)(3) organization. Funding would begin at $3 million for FY 2023 and rise to $10 million for FY 2026.

The Secretary of Agriculture would be guided in implementing these programs by two committees. One – the committee of experts – would constitute representatives of the USFS, APHIS, ARS & State forestry agencies. The second – the advisory committee – would be composed of representatives of land-grant colleges and universities and affiliated State agriculture experiment stations, forest products industry, recreationists, and professional forester, conservation, and conservation scientist organizations.

Port-Orford cedar seedlings at USFS Dorena Center – a model for success! Photo provided by Richard Sniezko

Please contact your Member of Congress (Representative) and senators to urge them to support inclusion of these provisions in the Farm Bill. [Remember: they work for us!] Telling them of your support for these bills is especially important if your Representative or Senator is on the Agriculture Committee. I list those legislators here:

State	HOUSE AGRIC COMM	SENATE AGRIC COMM
AL	Barry Moore	Tommy Tuberville
AR	Rick Crawford	John Boozman
CA	Doug Lamalfa John Duarte Jim Costa Salud Carbajal
CO	Yadira Caraveo	Michael Bennet
CT	Jahana Hayes
FL	Kat Cammack Darren Soto
GA	Austin Scott David Scott Sanford Bishop	Raphael Warnock
HI	Jill Tokuda
IA	Randy Feenstra Zach Nunn	Joni Ernst Charles Grassley
IL	Mike Bost Mary Miller Nikki Budzinski Eric Sorensen Jonathan Jackson	Richard Durbin
IN	Jim Baird	Mike Braun
KS	Tracey Mann Sharice Davids	Roger Marshall
KY		Mitch McConnell
MA	Jim McGovern
ME	Chellie Pingree
MI	Elissa Slotkin	Debbie Stabenow
MN	Angie Craig	Amy Klobuchar Tina Smith
MO	Mark Alford
MS	Trent Kelly	Cindy Hyde-Smith
NC	David Rouzer Alma Adams
ND		John Hoeven
NE	Don Bacon	Deb Fischer
NJ		Cory Booker
NM	Gabe Vasquez	Ben Ray Lujan
NY	Marc Molinaro Nick Langworthy	Kirsten Gillibrand
OH	Max Miller Shontel Brown	Sherrod Brown
OK	Frank Lucas
OR	Lori Chavez-Deremer Andrea Salinas
PA	Glenn Thompson	John Fetterman

SD	Dusty Johnson	John Thune
TN	Scott Desjarlais Brad Finstad
TX	Ronny Jackson Monica de la Cruz Jasmine Crockett
VA	Abigail Spanberger
VT	Peter Welch
WA	Marie Gluesenkamp Perez
WI	Derrick van Orden

Posted by Faith Campbell

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

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

www.fadingforests.org

Global Overview of Bioinvasion in Forests

black locust – one of the most widespread invasive tree species on Earth; photo via Flickr

In recent years there has been an encouraging effort to examine bioinvasions writ large see earlier blogs re: costs of invasive species – here and here. One of these products is the Routledge Handbook of Biosecurity and Invasive Species (full citation at end of this blog). I have seen only the chapter on bioinvasion in forest ecosystems written by Sitzia et al. While they describe this situation around the globe, their examples are mostly from Europe.

Similar to other overviews, this article re-states the widely-accepted attribution of rising numbers of species introductions to globalization, especially trade. In so doing, Sitzia et al. assert that the solution is not to curtail trade and movement of people, but to improve scientific knowledge with the goal of strengthening biosecurity and control programs. As readers of this blog know, I have long advocated more aggressive application of stronger restrictions on the most high-risk pathways. Still, I applaud efforts to apply science to risk assessment.

Sitzia et al. attempt to provide a global perspective. They remind readers that all major forest ecosystems of Earth are undergoing significant change as a result of conversion to different land-uses; invasion by a wide range of non-native introduced species—including plants, insects, and mammals; and climate change. These change agents act individually and synergistically. Sitzia et al. give greater emphasis than other writers to managing the tree component of forests. They explain this focus by asserting that forest management could be either the major disturbance favoring spread of non-native species or, conversely, the only way to prevent further invasions. They explore these relationships with the goal of improving conservation of forest habitats.

Japanese stiltgrass invasion; photo by mightyjoepye via Flickr

Sitzia et al. focus first on plant invasions. They contend that – contrary to some expectations – plants can invade even dense forests despite competition for resources. They cite a recent assessment by Rejmánek & Richardson that identified 434 tree species that are invasive around Earth. Many of these species are from Asia, South America, Europe, and Australia. These non-native trees can drive not only changes in composition but also in conservation trajectories in natural forests. However, the example they cite, Japanese stilt grass (Microstegium vimineum) in the United States, is not a tree! Sitzia et al. note that in other cases it is difficult to separate the impacts of management decisions, native competitive species, and non-native species.

Sitzia et al. note that plant invasions might have a wide array of ecological impacts on forests. They attempt to distinguish between

“drivers” of environmental change – including those with such powerful effects that they call them “transformers”;
“passengers” whose invasions are facilitated by other changes in ecosystem properties; and
“backseat drivers” that benefit from changes to ecosystem processes or properties and cause additional changes to native plant communities.

An example of the last is black locust (Robinia pseudoacacia). This North American tree has naturalized on all continents. It is a good example of the management complexities raised by conflicting views of an invasive species’ value, since it is used for timber, firewood, and honey production.

Sitzia et al. then consider invasions by plant pathogens. They say that these invasions are one of the main causes of decline or extirpations in tree populations. I applaud their explicit recognition that even when a host is not driven to extinction, the strong and sudden reduction in tree numbers produces significant changes in the impacted ecosystems.

American chestnut – not extinct but ecological role gone; photo by F.T. Campbell

Sitzia et al. contend that social and economic factors determine the likelihood of a species’ transportation and introduction. Specifically, global trade in plants for planting is widely recognized as being responsible for the majority of introductions. Introductions via this pathway are difficult to regulate because of the economic importance (and political clout) of the ornamental plants industry, large volumes of plants traded, rapid changes in varieties available, and multiple origins of trade. As noted above, the authors seek to resolve these challenges by improving the scientific knowledge guiding biosecurity and control programs. In the case of plant pathogens, they suggest adopting innovative molecular techniques to improve interception efficiency, esp. in the case of latent fungi in asymptomatic plants.

The likelihood that a pathogen transported to a new region will establish is determined by biogeographic and ecological factors. Like other recent studies, Sitzia et al. attempt to identify important factors. They name a large and confusing combination of pathogen- and host-specific traits and ecosystem conditions. These include the fungus’ virulence, host specificity, and modes of action, reproduction, and dispersal, as well as the host’s abundance, demography, and phytosociology. A key attribute is the non-native fungus’ ability to exploit micro-organism-insect interactions in the introduced range. (A separate study by Raffa et al. listed Dutch elm disease as an example of this phenomenon.) I find it interesting that they also say that pathogens that attack both ornamental and forest trees spread faster. They do not discuss why this might be so. I suggest a possible explanation: the ornamental hosts are probably shipped over wide areas by the plant trade.

surviving elms in an urban environment; photo by F.T. Campbell

Sitzia et al. devote considerable attention to bioinvasions that involve symbiotic relationships between bark and ambrosia beetles and their associated fungi. These beetles are highly invasive and present high ecological risk in forest ecosystems. Since ambrosia beetle larvae feed on symbiotic fungi carried on and farmed by the adults inside the host trees, they are often polyphagous. Bark beetles feed on the tree host’s tissues directly, so they tend to develop in a more restricted number of hosts. Both can be transported in almost all kinds of wood products, where they are protected from environmental extremes and detection by inspectors. Sitzia et al. specify the usual suspects: wood packaging and plants for planting, as ideal pathways. These invasions threaten indigenous species by shifting the distribution and abundance of certain plants, altering habitats, and changing food supplies. The resulting damage to native forests induces severe alterations of the landscape and causes economic losses in tree plantations and managed forests. The latter losses are primarily in the high costs of eradication efforts – and their frequent failure.

Eucalyptus plantation in Kwa-Zulu-Natal, South Africa; photo by Kwa-Zulu-Natal Department of Transportation

Perhaps their greatest contribution is their warning about probable damage caused by invasive forest pests in tropical forests. (See an earlier blog about invasive pests in Africa.) Sitzia et al. believe that bark and ambrosia beetles introduced to tropical forests threaten to cause damage of the same magnitude as climate change and clear cutting, but there is little information about such introductions. Tropical forests are exposed to invading beetles in several ways:

1) A long history of plant movement has occurred between tropical regions. Sitzia et al. contend that the same traits sought for commercial production contribute to risk of invasion.

2) Logging and conversion of tropical forests into plantation forestry and agriculture entails movement of potentially invasive plants to new areas. Canopies, understory plant communities, and soils are all disturbed. Seeds, insects, and pathogens can be introduced via contaminated equipment.

3) Less developed nations are often at a disadvantage in managing potential invasion. Resources may be fewer, competing priorities more compelling, or potential threats less obvious.

Sitzia et al. call for development of invasive species management strategies that are relevant to and realistic for less developed countries. These strategies must account for interactions between non-native species and other aspects of global environmental change. Professional foresters have a role here. One clear need is to set out practices for dealing with conflicts between actors driven by contrasting forestry and conservation interests. These approaches should incorporate the goals of shielding protected areas, habitat types and species from bioinvasion risk. Sitzia et al. also discuss how to address the fact that many widely used forestry trees are invasive. (See my earlier blog about pines planted in New Zealand.)

planted forest in Sardinia, Italy; photo by Torvlag via Flickr

In Europe, bark beetle invasions have damaged an estimated ~124 M m²between 1958 and 2001. Sitzia et al. report that the introduction rate of non-native scolytins has increased sharply. As in the US, many are from Asia. They expect this trend to increase in the future, following rising global trade and climate change. Southern – Mediterranean – Europe is especially vulnerable. The region has great habitat diversity; a large number of potential host trees; and the climate is dry and warm with mild winters. The region has a legacy of widespread planting of non-native trees which are now important components of the region’s economy, history and culture. These include a significant number of tree species that are controversial because they are – or appear to be – invasive. Thus, new problems related to invasive plants are likely to emerge.

Noting that different species and invasion stages require different action, Sitzia et al. point to forest planning as an important tool. Again the discussion centers on Europe. Individual states set forest policies. Two complications are the facts that nearly half of European forests are privately owned; and stakeholders differ in their understanding of the concept of “sustainability”. Does it mean ‘sustainable yield’ of timber? Or providing multiple goods and services? Or sustaining evolution of forest ecosystems with restrictions on the use of non-native species? Resolving these issues requires engagement of all the stakeholders.

Sitzia et al. say there has recently been progress. The Council of Europe issued a voluntary Code of Conduct on Invasive Alien Trees in 2017 that provides guidelines on key pathways. A workshop in 2019 elaborated global guidelines for the sustainable use of non-native tree species, based on the Bern Convention Code of Conduct on Invasive Alien Trees. The workshop issued eight recommendations:

Use native trees, or non-invasive non-native trees;
Comply with international, national, and regional regulations concerning non-native trees;
Be aware of the risk of bioinvasion and consider global change trends;
Design and adopt tailored practices for plantation site selection and silvicultural management;
Promote and implement early detection and rapid response programs;
Design and adopt practices for invasive non-native tree control, habitat restoration, and for dealing with highly modified ecosystems;
Engage with stakeholders on the risks posed by invasive NIS trees, the impacts caused, and the options for management; and
Develop and support global networks, collaborative research, and information sharing on native and non-native trees.

SOURCE

Sitzia, T., T. Campagnaro, G. Brundu, M. Faccoli, A. Santini and B.L. Webber. 2021 Forest Ecosystems. in Barker, K. and R.A. Francis. Routledge Handbook of Biosecurity and Invasive Species. ISBN 9780367763213

Posted by Faith Campbell

www.fadingforests.org

Help Fight for $$ to Protect Forests

Help Fight for Money to Protect Forests

This blog asks YOU!!! to support funding for some of the key USDA programs. This blog focuses on USDA’s Animal and Plant Health Inspection Service (APHIS). APHIS is responsible for preventing introduction of pests that harm agriculture, including forests; and for immediate efforts to eradicate or contain those pests that do enter. While most port inspections are carried out by the Department of Homeland Security Bureau of Customs and Border Protection, APHIS sets the policy guidance. APHIS also inspects imports of living plants.

Please help by contacting your members of the House and Senate Appropriations Committees. I provide a list of members – by state – at the end of this blog. APHIS is funded by the House and Senate Appropriations Subcommittees on Agriculture and Related Agencies. These Subcommittees have scheduled hearings on the topic and I’ve drafted written testimony for them. I expect CISP will be joined by additional members of the Sustainable Urban Forest Coalition in signing the testimony. You can add the crucial voice of constituent’s support.

I will blog soon about funding for USDA’s Forest Service (USFS) – I don’t yet have necessary information to suggest specific funding levels.

Your letter or email need be no more than a couple paragraphs. To make the case for greater funding, feel free to pick-and-choose from the information that follows. Your greatest impact comes from speaking specifically about what you know and where you live.

These are the specific dollar amounts we’d like you to ask for. The rationale for each is below.

Appropriations for APHIS programs (in $ millions)

Program	FY 2022 (millions)	FY 2023	FY 2024 Pres.’ request	Our ask
Tree & Wood Pest	$61	$63	$64	$65 M
Specialty Crops	$210	$216	$222	$222 M
Pest Detection	$28	$29	$30	$30 M
Methods Development	$21	$23	$23	$25 M

The Costs of Introduced Pests

Introduced pests threaten many forest products and services benefitting all Americans, including wood products, wildlife habitat, carbon sequestration, clean water and air, storm water management, lower energy costs, improved health, aesthetic enjoyment, and related jobs. Already, the 15 most damaging non-native pests threaten at least 41% of forest biomass in the “lower 48” states. In total, these 15 species have caused an additional annual conversion of live biomass to dead wood at a rate similar in magnitude to that attributed to fire (5.53 TgC per year for pests versus 5.4 to 14.2 TgC per year for fire) [Fei et al.; full citation at end of blog; see also earlier].

tanoaks killed by SOD; Oregon Department of Forestry photo

These pests also impose significant costs that are borne principally by municipal governments and homeowners. As more pests have been accidentally introduced over time, these costs have risen. A study published last year [Hudgins et al.] projected that by 2050 1.4 million street trees in urban areas and communities will be killed by introduced insect pests. Municipalities on the forefront include Milwaukee and Madison Wisconsin; the Chicago area; Cleveland; and Baltimore, Towson, and Salisbury, Maryland. Removing and replacing these trees is projected to cost cities $30 million per year. Additional urban trees – in parks, on homeowners’ properties, and in urban woodlands – are also expected to die and require removal and replacement.

Pathways of Introduction

Tree-killing pests are linked to the international supply chain. Many pests—especially the highly damaging wood-borers like emerald ash borer, Asian longhorned beetle, polyphagous and Kuroshio shot hole borers, and redbay ambrosia beetle—arrive in inadequately treated crates, pallets, and other forms of packaging made of wood. Other pests—especially plant diseases like sudden oak death and sap sucking insects like hemlock woolly adelgid—come on imported plants. Some pests take shelter, or lay their eggs, in or on virtually any exposed hard surface, such as steel, decorative stone, or shipping containers.

infested wood from a crate; Oregon Department of Agriculture photo

Wood Packaging

Imports from Asia have historically transported the most damaging pests, e.g., Asian longhorned beetle, emerald ash borer, redbay ambrosia beetle, and the invasive shot hole borers. For decades goods from Asia have dominated imports. As of February 2022, U.S. imports from Asia were running at a rate of 20 million shipping containers per year. A recent analysis [Haack et al.; see also here] indicates that at least 33,000 of these shipping containers, perhaps twice that number, are carrying a tree-killing pest. These facts have led scientists to project [Leung et al.] that by 2050, the number of non-native wood-boring insects established in the US could triple. Hudgins et al. say the greatest damage would occur if an Asian wood-boring insect that attacks maples or oaks were introduced. Such a pest could kill 6.1 million trees and cost American cities $4.9 billion over 30 years. The risk would be highest if this pest were introduced to the South – and U.S. southern ports are receiving more direct shipments from Asia after the expansion of the Panama Canal in 2016. https://www.nivemnic.us/?m=202207

After introduction of the ALB, APHIS acted to curtail further introductions in wood packaging from China. First – in 1998 – APHIS required China to treat its wood packaging. Second, it worked with foreign governments to develop the International Standard for Phytosanitary Measures (ISPM) #15. The U.S. and Canada began phasing in ISPM#15 in 2005 with full implementation in 2006. Under ISPM#15, all countries shipping goods to North America must treat their wood packaging according to specified protocols with the goal of “significantly reducing” the risk that pests will be present.

However, as I have often blogged [see blogs under “wood packaging” category on this site] ISPM#15 has fallen short. Haack et al. found that as recently as 2020, 0.22% [1/5^th of 1 percent] of the shipping containers entering the U.S. were infested by a tree-killing insect. This equates to tens of thousands of containers harboring tree-killing insects.

Worse, the data indicate that our trade partners’ compliance with the rules has deteriorated; the “approach rate” of pest-infested wood packaging fell in 2005-2006, but has since gone back up.

The most troubling offender is China. Although required since 1998 to treat its wood packaging, China consistently has one of the highest pest approach rates: it was 0.73% [or ¾ of 1%] during the 2010- 2020 period. This is three times the global average for the period. Since China supplied 40.7% of U.S. imports in 2022 [Szakonyi], or 5,655,000 containers. Thus China alone might be sending to the U.S. 30,000 containers infested with tree-killing insects. These pests threaten our urban, rural, and wildland forests and reduce forest productivity, carbon sequestration, the rural job base, water supplies and quality, and many other ecosystem services.

ISPM#15 falls short at the global level. The fact that a pallet or crate bears the mark indicating that it complies with ISPM#15 has not proved to be reliable.

You might ask your Member of Congress or Senators to ask APHIS what steps it will take to correct the problem of Chinese non-compliance. (Remind him or her that that the Asian longhorned beetle, emerald ash borer, and many other insects of so-far lesser impact were introduced in wood packaging from China.

Asian longhorned beetle

Remind them also that the Department of Homeland Security’s Bureau of Customs and Border Protection has twice enhanced its enforcement of wood packaging rules. In 2017 it began penalizing importers of non-compliant wood packaging under Title 19 United States Code (USC) §1595a(b) or under 19 USC §1592. In 2021, it incorporated the wood packaging requirements into its voluntary C-TPAC program.)

You might also urge them to ask APHIS what steps it is taking at the global level to improve the efficacy of ISPM#15 – or to replace it if necessary to ensure that pests are not being introduced.

Imported Plants (“Plants for Planting”)

Some pest types—especially plant diseases like sudden oak death and sap-sucking insects like hemlock woolly adelgid—come on imported plants. The U.S. imported about 5 billion plants in 2021 [MacLachlan]. Recent introductions probably via this pathway include several pathogens — Phytophthoras, rapid ʻōhiʻa death in Hawai`i, beech leaf disease (established from Ohio to Maine), and boxwood blight. Insects have also been introduced on imported plants recently; one example is the elm zigzag sawfly (present in North Carolina, Virginia, and New York and Ontario). https://www.nivemnic.us/?p=4115

An analysis of data from 2009 [Liebhold et al.] found that approximately 12% of plant shipments were infested by a pest. This pest approach rate is more than 50 times higher than the 0.22% approach rate for wood packaging. APHIS has adopted several changes to its phytosanitary system for imported plants in the decade since 2009. A few studies have been published, but they have focussed on insects and excluded pathogens. We have noted that pathogens continue to be introduced via the plant trade. Therefore, please ask your Member or Senators to ask APHIS to facilitate an independent analysis of the efficacy of the agency’s current phytosanitary programs to prevent introductions of pests on important plants, with an emphasis on introductions of plant pathogens.

APHIS is responsible for preventing spread of the SOD pathogen, Phytophthora ramorum, through trade in nursery plants. In recent years California has had few detections in nurseries and little expansion in forests – but the situation suggests that this good news is probably more the result of the drought than of program efficacy. In cooler, wetter conditions in Oregon and Washington, detections in nurseries and alarming detections in the forest or plantings continue.

In 2022, the APHIS SOD Program supported detection and regulatory activities in 25 states. P. ramorum was detected at 18 establishment, 12 of which were first-time detections. The California nursery regulatory program – which is funded by APHIS – saw reduced funding in 2022. We think these cuts are unwise since this year’s very wet winter will probably lead to a new disease outbreaks. Programs in Oregon and Washington continue to detect infestations in additional retailers brought in by plants bought from other nurseries. Washington responded to four separate “trace forward” incidents, one involving more than 160 residential sites. Clearly, the federal-state program is not succeeding in eradicating P. ramorum from nurseries. Please suggest that your Congressperson and Senators ask APHIS what steps it is taking to improve the efficacy of the SOD program.

SOD-infected rhodoendron on plants in Indiana; photo by Indiana Department of Natural Resources

In the East, P. ramorum was found in three of 65 streams sampled in 10 states in 2022 (reaching across the Southeast from Mississippi through North Carolina, plus Texas, Maryland, Pennsylvania, and Illinois). One stream is troubling: a first-time detection in South Carolina, with no obvious nursery source. Since stream sampling began, P. ramorum has been detected from eight streams in four states, Alabama, Mississippi, North Carolina, and now South Carolina. The pathogen has been present in some of these streams for more than 10 years.

Oregon faces particularly high risks. Three of the four known strains of P. ramorum are established in Oregon forests. One of them, the EU1 lineage, is more aggressive than the NA1 clonal lineage already present in forests. In addition, the EU1 strain might facilitate sexual reproduction of the pathogen, thus exacerbating Oregon’s struggle to contain the disease.

As we know, introduced pests do not stay in the cities where they first arrived — they spread! Often that spread is facilitated by our movement of firewood, plants, or outdoor household goods such as patio furniture.

The beech trees so important to wildlife conservation in the Northeast are under attack by two pathogens and at risk to an insect. Most alarming is the spread – in a dozen years! — of beech leaf disease DMF from Ohio to Maine. A leaf-feeding weevil is spreading south in eastern Canada. Please suggest that your Member or Senators to ask APHIS what steps it is taking to prevent the weevil’s introduction to the U.S.

‘Ōhi‘a trees make up 80% of the biomass of forests in both wet and dry areas of the Hawaiian archipelago. It is under attack by two diseases caused by introduced pathogens first detected in 2010. ‘Ōhi‘a forests support more threatened and endangered species than any other forest system in the U.S. They also play a uniquely important role in providing other ecosystem services, including water supplies.

Asking for the Money Pest Problems Deserve

To respond effectively to these pests and to the others that will be introduced in coming years, the key APHIS programs identified above must have adequate funds. The funding levels I request – and hope you will support – are lower than I would wish, but everyone expects the Congress to refuse significant increases in funding (see table at beginning of this blog).

The Tree and Wood Pests account supports eradication and control efforts targeting principally the ALB and spongy (= gypsy) moth. Eradicating the ALB normally receives about two-thirds of the funds. The programs in Massachusetts, New York, Ohio, and South Carolina must continue until eradication succeeds.

Oregon detected the EAB in 2022. Although the state and Portland have been preparing for a decade for this eventuality, there will still be significant impacts. Four percent of Portland’s street trees are ash – more than 9,000 trees. Young ash constitute three percent of young trees in parks. Loss of Oregon’s ash will also have severe ecosystem impacts. In Willamette Valley wetlands, ash constitutes up to 100% of the forest trees. Washington and California are also concerned. Indeed, the Hudgins study identified Seattle and Takoma as likely to lose thousands of ash trees. The numerous ash in riparian forests, windbreaks, and towns of North Dakota are also at risk since the EAB is established in South Dakota, Minnesota, and Manitoba.

APHIS manages damaging pests introduced on imported plants or other items through its Specialty Crops program. The principal example is its efforts to prevent spread of the SOD pathogen through the interstate trade in nursery plants. We noted above that this program is not as successful as it should be. We support the Administration’s request for $222 million; however, you might suggest that your Member or Senator urge APHIS to allot adequate funding under this budget line to management of SOD, rapid ʻōhiʻa death pathogens in Hawai`i, and beech leaf disease and elm zig-zag sawfly in the East.

The Pest Detection program is key to the prompt detection of newly introduced pests that is critical to successful pest eradication or containment. The “Methods Development” program enables APHIS to improve development of essential detection and eradication tools.

The Administration’s request include a $1 million emergency fund. This is far below the level needed to respond when a new pest is discovered. Funding constraints have hampered APHIS’ response to past pest incursions.

Please note that many of the members of the Agriculture Appropriations Subcommittee are from states where non-native pests are probably not top of mind. It is important that everyone that knows about these threats communicate with your Member/Senators!!

Members of House or Senate Subcommittees that Fund APHIS

(Names of Senators are italicized)

STATE	MEMBER	APHIS APPROP	HOUSE	SENATE
AK	Lisa Murkowski			X
AL	Jerry Carl Katie Britt	X	X	X
Calif	Barbara Lee David Valadao Josh Harder Diane Feinstein	X X X	X X X	X
FL	Debbie Wasserman Scultz Scott Franklin	X X	X X
GA	Sanford Bishop	X	X
ID	Mike Simpson		X
IL	Lauren Underwood	X	X
KS	Jerry Moran	X		X
KY	Mitch McConnell	X		X
LA	Julia Letlow Ashley Hinson	X X	X X
MD	Andy Harris Chris Van Hollen	X	X	X
ME	Chellie Pingree Susan Collins	X X	X	X
MI	John Moolenaar Gary Peters	X X	x	X
MN	Betty McCollum	X	X
MS	Cindy Hyde-Smith	X		X
MT	Jon Tester Ryan Zinke	X	X	X
NB	Deb Fischer			X
ND	John Hoeven	X		X
NM	Martin Heinrich	X		X
NV	Mark Amodei		X
OH	Marcy Kaptur	X	X
OR	Jeff Merkley	X	X	X
PA	Guy Reschenthaler	X	X
RI	Jack Reed			X
TX	Michael Cloud Jake Ellzey	X	X X
UT	Chris Stewart		X
VA	Ben Cline	X	X
WA	Dan Newhouse Derek Kilmer	X	X X
WV	Shelly Moore Capito Joe Manchin	X		X X
WI	Mark Pocan Tammy Baldwin	X X	X	X

SOURCES

Fei, S., R.S. Morin, C.M. Oswalt, and A.M. 2019. Biomass losses resulting from insect and disease invasions in United States forests. PNAS August 27, 2019. Vol. 116 No. 35 17371–17376

Haack R.A., J.A. Hardin, B.P. Caton and T.R. Petrice .2022. Wood borer detection rates on wood packaging materials entering the United States during different phases of ISPM#15 implementation and regulatory changes. Front. For. Glob. Change 5:1069117. doi: 10.3389/ffgc.2022.1069117

Hudgins, E.J., F.H. Koch, M.J. Ambrose, and B. Leung. 2022. Hotspots of pest-induced US urban tree death, 2020–2050. Journal of Applied Ecology

Leung, B., M.R. Springborn, J.A. Turner, and E.G. Brockerhoff. 2014. Pathway-level risk analysis: the net present value of an invasive species policy in the US. Front Ecol Environ 2014; doi:10.1890/130311

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. Frontiers in Ecology.

MacLachlan, M.J., A. M. Liebhold, T. Yamanaka, M. R. Springborn. 2022. Hidden patterns of insect establishment risk revealed from two centuries of alien species discoveries. Sci. Adv. 7, eabj1012 (2021).

Szakonyi, M. 2023. Sourcing shift from China pulls US import share to more than a decade low.

One State’s Program Illustrates Importance of Federal Funding

Dead ash along Mattawoman Creek in 2019; Mattawoman Creek is a Maryland tributary of the Potomac River, hence of the Chesapeake Bay. Photo courtesy of Leslie A. Brice

In this blog I describe one state’s forest health efforts – Virginia. The pertinent lesson is the importance of external funding, especially that provided by USFS Forest Health Protection program, in supporting states’ efforts. Is your state’s forest health program as dependent upon federal funding as Virginia’s is? If so, there is a role for everyone: lobby your Congressional representative and senators to increase funding for this program!

I have based most of this blog on the Virginia Department of Forestry’s annual report for 2022.

Forests grow on more than 16 million acres in Virginia, or 62% of the Commonwealth’s land area. Eighty percent of these forests are hardwood or hardwood-pine. They break down as follows: 61% oak-hickory; 11% oak-pine; 5% bottomland hardwood; and 2% maple-beech-birch. A fifth of the forest is pine, composed of pine plantation (14%) and natural pine (7%). The long term trend is growth, especially among hardwoods.

The report devotes much of its attention to the agency’s programs to advise private landowners (individuals own 80% of the Commonwealth’s forestland); fire management (including prescribed burns); and state and federal conservation programs (e.g., easements). A major program shares reforestation costs on harvested pine lands. In 2022, this program assisted reforestation practices on 74,702 acres. Virginia has an impressive tree-raising program. VDOF grows more than 40 species, including longleaf and shortleaf pine, several spruce species, and dozens of hardwoods. The aim is to provide stock suited for the Commonwealth’s soils and climate. Many of the hardwood species are grown from acorns and seeds collected and donated by volunteers.

VDOF also helps to protect and improve the Commonwealth’s water quality through tree planting and sound forest management. VDOF has an unusual responsibility: enforcing the Virginia Silvicultural Water Quality Law.

The report also summarizes several urban and community forestry programs focused on education, community engagement, tree selection, and grants for tree planting to ensure canopy retention & management.

Forest Health – Importance of Federal Funding

Spongy Moth

Slightly over 1 million acres was mapped by aerial surveys in FY22. I believe the funding for these surveys came largely from the USFS. The surveys detected heavy to moderate defoliation by the spongy moth on 24,493 acres (almost twice the area detected in FY21). The spongy moth infestation is primarily in counties on the western side of the state, in the mountainous region, which has the highest densities of oaks and other hardwoods.

Spotted Lanternfly

The spotted lanternfly (SLF) was detected in Virginia early – in 2018 in Winchester at the northern end of the Shenandoah Valley. Winchester is connected to central Pennsylvania by Interstate 81, so rapid movement of SLF to Virginia from outbreaks slightly to the east of I-81 in Pennsylvania doesn’t surprise me. SLF has been spreading south along the mountains and over the Blue Ridge to Loudoun and Fairfax counties (in 2022). Fairfax County has announced a four-year, $200,000 effort to try to slow SLF spread by eradicating high densities of its preferred host, Ailanthus, from two county parks in the far south and north ends of the county. Ailanthus removal requires not just cutting the trees, but applying herbicide to prevent sprouting from the roots. This work is funded by the county, the local park authority and a $20,000 grant from the regional energy company, Dominion Energy Charitable Foundation.

Emerald Ash Borer

Virginia has six species of ash: white and green (both common), and smaller populations of black, blue, pumpkin and Carolina. EAB is now confirmed in 84 counties – most of the Commonwealth except the far southeast. The Department of Forestry treats 130 – 150 trees per year – half or more on state lands. At least in FY21, the funding came from federal sources. The report also notes outreach efforts at two minor league baseball games. Virginia recently adopted a priority of protecting the Chesapeake Bay watershed by promoting tree planting in riparian forest buffers. The EAB threatens this goal; see the photo (at top) of ash mortality along a Maryland tributary of the Bay. In 2021, EAB was detected in Gloucester County – a peninsula east of the York River that has Bay shoreline on the eastern side, tributary on the west (see photo).

Gloucester Point – Virginia Institute of Marine Sciences “living shoreline”; EAB was detected in Gloucester County in 2021, threatening riparian areas. Photo courtesy of the Chesapeake Bay Program

Threats to Beech

Beech bark disease is present in the western mountainous parts of the Commonwealth. One new county – Augusta – was detected in 2022. Three other counties are infested with the scale, but the fungal pathogen has not yet been detected. The alarming new threat, beech leaf disease, was detected in Prince William County in 2021. In 2022, it was confirmed in neighboring Fairfax County. The source of funding is not specified.

beech in a typical northern Virginia second-growth forest; photo by F.T. Campbell

Laurel Wilt Disease

I am pleased that the Commonwealth is paying attention to laurel wilt disease, which has been spreading north on sassafras. The closest outbreaks are in Tennessee, to the southwest of Virginia. The Commonwealth hosted a detection training program attend by 26 participants from six agencies from three states. The report does not specify the source of the funding.

Southern Pine Beetle

Virginia has also utilized funding from the USFS FHP program to manage the southern pine beetle. Since the program’s inception in 2004, Virginia has thinned pines on more than 70,000 acres, including 4,240 acres in FY22.

Invasive Plants

USFS FHP invasive species grants funded control treatments of invasive plants on somewhat less than 1,300 acres of state lands. Different figures on different pages of the report cause confusion. However, it is clear that nearly all the funds came from the USFS FHP program. Ailanthus was the main target; other species mentioned are privet, mimosa, autumn olive and Miscanthus.

State Funding of Conservation Initiatives; Will They Continue?

While the state’s government was controlled by Democrats, the governor and state legislature launched new programs with broader conservation goals. It is unclear whether they will continue now that Republicans have won the governorship and control of the House of Delegates.

Among the programs enjoying increased funding from the state budget during the current two-year cycle are

Efforts to restore depleted populations of two groups of tree taxa, shortleaf and longleaf pines. The emphasis has shifted to longleaf pine: the number of projects and acreages rose from 220 acres in FY21 to 1,212 acres in FY22. Restoration of shortleaf pine forests was limited to slightly over 600 acres in both years.
Programs to improve management of hardwood stands. These projects included crop tree release, control of “invasive species” (I think probably targetting invasive plants), prescribed burning and commercial thinning. There were also several demonstration projects on state-owned lands, a small land-owner planning assistance program, and training of state foresters and private consulting foresters in hardwood management. Apparently these aspects had been largely ignored in the past.
Creation of a dedicated Watershed program focused on increasing riparian forest buffers. This section of the report does not mention the threat posed by loss of ash to the emerald ash borer (EAB) [see EAB section above]
Urban forestry projects, many linked to protecting surface and ground water (including Chesapeake Bay watershed).

Posted by Faith Campbell

www.fadingforests.org

see also the article about beech leaf disease in the mid-Atlantic region written by Gabe Popkin; posted here

Protecting ash & hemlock – latest information

nearly dead ash in Shenandoah National Park; photo by F.T. Campbell

I participated in the annual USDA Interagency Invasive Species Research Forum in Annapolis in January 2023; as usual, I learned interesting developments. I focus here on updates re: efforts to protect ash and hemlock

Hopeful Developments re: countering EAB to protect ash

There are hopeful results in both the biocontrol and resistance breeding programs. The overall goal is to maintain ash as a viable part of the North American landscape.

Biocontrol

Juli Gould (APHIS) reminded us that the agency began a classical biocontrol program targetting emerald ash borer (EAB) in 2003 – only a year after EAB had been detected and much earlier than is the usual practice. [Thank you, former APHIS PPQ Deputy Administrator Ric Dunkle!] By 2007 scientists had identified, tested, and approved three agents; a fourth was approved in 2015.

Nicole Quinn (University of Florida) stressed that the egg prarasitoid, Oobius — if it is effective — could prevent EAB from damaging trees. However, it is so small that it is very difficult to sample. One small study demonstrated that Oobius will parasitize EAB eggs laid in white fringe trees (Chionanthus virginicus) as well as in ash. This is important because it means this secondary host is not likely to be a reservoir of EAB.

The numbers

According to Ben Slager (APHIS), more than 8 million parasitoids have been released at 950 sites since the program began in 2007. These releases have been in 418 counties in 31 states, DC, and four Canadian provinces. Still, these represent just 28% of infested counties. Parasitoids have been recovered in 21 states and two provinces.

Rafael de Andrade (University of Maryland) specified that these releases included more than 5 million Tetrastichus in 787 sites; ~2.5 million Oobius in 828 sites in 30 states; ~500,000 Spathius agrili – lately only north of the 40^th parallel. Releases of Spathius galinae began in 2015; so far ~ 470,000 in 395 sites.

Impact

Several presenters addressed questions of whether the agents are establishing, dispersing, and – most important – improving ash survival. Also, can classical biocontrol be integrated with other management techniques, especially use of the pesticide emamectin benzoate.

Dispersal

Several studies have shown that the four biocontrol agents disperse well (with the caveat that Oobius is very difficult to detect so its status is much less certain).

Implementation considerations

De Andrade found that the longer the delay between the date when EAB was detected and release of Oobius, the less likely Oobius will be recovered. Tetrastichus surprised because the higher the numbers released, the fewer were recovered. He could determine no association between recovery of S. agrili and variations in release regime [numbers released; delay in releasing biocontrol agents; or frequency of releases]. He said it is too early to assess Sp. galinae since releases began only in 2015, but he did see expected relationship to propagule pressure – the more wasps released, the higher the number that were recovered. Sp. galinae did surprise in one way: it seemed to perform better at lower latitudes. De Andrade noted he was working data from less than half of release sites. He asked collaborators to submit data!!!!

Initial signs of ash persistence and recovery

Claire Rutledge (Connecticut Agriculture Experiment Station) determined that

More large trees were surviving in plots where the biocontrol agents were released
EAB density was lower at long-invaded sites
Parasitism rates were similar across release age treatments and release/control plots

Gould focused on protecting saplings so they can grow into mature trees which could be sources of seeds to establish future generations. She noted that there are many “aftermath” forests across the northern United States – those dominated by ash saplings.

In Michigan, at a site of green ash, as of 2015 – 2021, EAB populations are still low, parasitism rate by Tetrastichus and S. galinae high. The percentage of saplings that remained healthy was greater than 80%. There were similar findings in white ash in New York: very low EAB larval density; and more than 70% of ash saplings had no fresh galleries. Gould reported that Tetrastrichus impcts could be detected within three years of release.

So, EAB are being killed by the biocontrol agents combined with woodpecker predation; but in their fourth instar, after considerable damage to the trees.

downy woodpecker in Central Park, NYC. photo by Steven Bellovin, Columbia University

Jian Duan reported on two long-term studies in green & white ash in Michigan and New England. His team used the most labor-intensive but best approach to determine EAB larval mortality and the cause – debarking trees – to determine whether the EAB larva were parasitized, were preyed on by woodpeckers, or were killed by undetermined cause, such as tree resistance, disease, or competition. In Michigan, he linked a crash of EAB population in 2010 was caused by Tetrastichus; EAB tried to recover, but crashed again, due to S. galinae. EAB larval densities had been reduced to 10 / m². Predation by abundant woodpeckers and the native parasitoid Atanycolus was also important.

In New England, EAB has also declined from 20-30 larvae /m² to ~ 10 m².

In Michigan, healthy ash with dbh of larger than 5 inches were much more plentiful in sites where parasitoids had been released. Their survival/healthy rate also was much higher in release sites but the difference declined as years passed. In New England there were growing numbers of healthy trees in 2021-22; (almost none in 2017). Duan conceded that he could not prove a direct link but the data points to recovery.

Tim Morris (SUNY-Syracuse) found that white ash saplings continued to die in large numbers, but the mortality rate was significantly below the rate in 2017. Canopy conditions varied; some trees that were declining in 2013 were recovering in 2017. Forty percent of “healthy” ash in 2013 continued recovering in 2021. Few living trees were declining; trees were either healthy or dead. He thinks probably a combination of genetics and presence of parasitoids explains which trees recover. Morris also reported some signs of regeneration.

beaver feeding on ash saplings, Fairfax County, Va;
photo by F.T. Campbell

At this point, I noted that in parts of northern Virginia, beavers have killed ash saplings. Morris reported finding the same in some sites in New York. Perhaps others have, also; my comment was greeted by laughter.

Theresa Murphy (APHIS) looked at integration of biocontrol and insecticide treatment in urban and natural sites. A study of black and green ash in Syracuse, NY Naperville, IL, and Boulder, CO found continued high parasitism by Tetrasticus and S. galinae and woodpecker attacks in trees treated with emamectin benzoate. Researchers could not detect Oobius. By 2020, most of the untreated trees had died but treated trees remained healthy.

Murphy has begun studying integration of biocontrol and pesticides in green and black ash forests. The goal is to protect large trees to ensure reproduction; the biocontrol agents do not yet protect the large trees. This is especially important for black ash because it declines very quickly after EAB invades. Sites have been established in New York, through collaboration with New York parks, Department of Environmental Conservation, and the Mohawk tribe. She is still looking for sites in Wisconsin – where EAB is spreading more slowly than expected.

1 of the infested ash in Oregon; photo by Wyatt Williams, ODF

Max Ragozzino of the Oregon Department of Agriculture reported on imminent release of biocontrol agents targetting the recently detected outbreak there. I am encouraged by the rapid response by both the state and APHIS.

EAB resistance in ash

Jennifer Koch (USFS) said the goal is not to produce populations where every seedling is fully EAB-resistant, but to develop populations of ash trees with enough resistance to allow continued improvement through natural selection while retaining sufficient genetic diversity to adapt to future stressors (changing climate, pests, diseases). The program has developed methods to quantify resistance in individuals.. Initial field selections of “lingering ash” were shown to be able to kill as many as 45 % of EAB larvae. Already green ash seedling families have been produced by breeding lingering ash parents. This first generation of progeny had higher levels of resistance, on average, than the parent trees. Each generation of breeding can increase the proportion of resistance. Although the bioassays to test for EAB-resistance are destructive (e.g., cutting and peeling to count numbers of surviving larvae), the potted ash seedling stumps can resprout. Once the new sprouts are big enough they are planted in field trials to correlate bioassay results with field performers. Poor performers are culled; those with higher levels of resistance remain and become sources of improved seed.

To ensure preservation of local adaptive traits, this process must be repeated with new genotypes to develop many seed orchards from across the species’ wide range. To support this work, concerned scientists are building multi-partner collaborative breeding networks. These organizations provide ways for citizens and a variety of partners to engage through monitoring and reporting lingering ash, making land available for test planting, and helping with the work of propagation.

See Great Lakes Basin Forest Health Collaborative » Holden Forests & Gardens (holdenfg.org), Monitoring and Managing Ash (MaMA) – A citizen-science-driven program for conservation and mitigation (monitoringash.org), and TreeSnap – Help Our Nation’s Trees! for more information.

Resistance levels in some of the first generation progeny were high enough for use in horticulture, where it is important that trees can remain healthy in challenging environments (street trees, city parks, landscaping, etc.). Koch hopes to develop about a dozen cultivars comprising the best-performing trees, appropriate for planting in parts of Ohio, Michigan, Indiana, and Pennsylvania. Local NGO partners are planting some of these promising genotypes in Detroit to see how they withstand EAB attack.

The threat to black ash is especially severe, and this species presents unique difficulties. While scientists found several seedlings from unselected seedlots had killed high levels of larvae, those deaths did not always result in better tree survival. Koch thinks the tree’s defense response becomes detrimental to tree by blocking transport of water and nutrients. She is working with experts in genomics and others, such as Kew Royal Botanic Gardens, to try to identify candidate trees for breeding programs. The genomics work has been supported by APHIS and the UK forest research agency, DEFRA. Michigan and Pennsylvania have supported the breeding work. USFS Forest Health Protection has supported work with black and Oregon ash (see below) (J. Koch, USFS, pers. comm.).

Koch has also begun working with Oregon ash, in collaboration with the USFS Dorena Genetic Resource Center (located in Cottage Grove, Oregon) and other partners.

dead hemlock in Massachusetts; photo by Ian Kinahan,
University of Rhode Island

Hemlock woolly adelgid

Scientists are still trying to find the right combination of biocontrol, chemical treatments, and silvicultural manipulation.

For several years, hope has focused on two has been on two predatory beetles, Laricobius nigrinus and L. osakiensis. Scott Salom (Virginia Tech) reports that release of these beetles over the past 20 years has had a significant impact on HWA density and tree photosynthetic rate and growth. However, Laricobius aredifficult to rear and they attack only the sistens generation of the adelgid. Ryan Crandall (University of Massachusetts) reports it has been difficult to establish these beetles in the Northeast. He links this difficulty is caused by temporary drops in HWA populations after cold snaps.

Scientists now agree that need to find predators that attack HWA during other parts of its lifecycle. Hope now focuses on silverflies — Leucotaraxis argenticollis and Le. piniperda. While both species are established in eastern North America, the clades in the east feed almost exclusively on pine bark adelgid, and have not begun attacking HWA. Biocontrol practitioners therefore collect flies in the Pacific Northwest for release in the east. Salom is increasing his lab’s capacity to rear silverflies and exploring release strategies.

Preliminary evidence indicates that the western clades of Leucotaraxis are establishing, although data are not yet definitive (Havill, USFS).

Detecting the presence of biocontrol agents presents several challenges. Tonya Bittner (Cornell) described efforts to use eDNA analysis for this. Some puzzles have persisted; e.g., at some sites, she detected eDNA but caught no silverflies. This raised the question of long eDNA associated with the original release might persist. Another problem is that the assay cannot separate the introduced western L. nigrinus from the native congener, L. rubus (which also does not feed on HWA). She continues efforts to improve this technique.

Others explored interactions of the biocontrol agents with insecticides. Salom is studying the impact of soil-applied insecticides on Laricobius populations, which aestivate in the soil. Preliminary results showed significant reduction in the beetle’s population under soil drench application but not under soil injection. He has not yet analyzed all the data.

Michigan is trying to prevent spread of HWA from five counties along the eastern shore of Lake Michigan (where HWA was introduced on nursery stock) to widespread hemlock forests in northern part of the state. Phil Lewis (APHIS) is studying persistence of systemic insecticides in hemlock tissues, particularly twigs and needles. The pesticides involved are imidacloprid, dinotefuran, and Olefin. He has found that pesticide levels are highest 18 – 22 months after treatment, then decline. They are significantly higher after trunk injection compared to bark spray or soil treatments. Imidacloprid had higher residues in twigs; dinotefuran in needles. This difference affects the likelihood of adelgids actually ingesting the toxin.

healthy hemlock in experimental gap; Jefferson National Forest, VA; photo by Bud Mayfield, USFS

Bud Mayfield (USFS) reported on his study of silvicultural strategies to support healthier hemlocks. While hemlocks normally thrive in shade, it has been determined that sunlight assists small trees reducing HWA sufficiently to counter the tree’s leaf-level stress. Small sapling hemlocks grown in sunlight fix more carbon and convert it to growth in shoots and trunk diameter.

Mayfield found promising immediate suppression of HWA in large gaps in Georgia and Tennessee. By the third year the saplings were still growing, although their faster growth had attracted more HWA. These findings were less clear farther north in central Virginia and western Maryland – Mayfield thinks because HWA pressure there is lower. However, managers must maintain the gaps by cutting rapidly-growing competing woody species. He plans to test this strategy farther north in Pennsylvania. He is still trying to determine the optimal size of the gap.

Posted by Faith Campbell

www.fadingforests.org

FY 23 Funding of Tree Pest Projects

*Phytophthora ramorum*-infected rhododendron plant; photo by Jennifer Parke, Oregon State University

APHIS has released the list of projects funded under §7721 of the Plant Protection Act in Fiscal Year 2023. Projects funded under the Plant Pest and Disease Management and Disaster Prevention Program (PPDMDPP) are intend to strengthen the nation’s infrastructure for pest detection and surveillance, identification, threat mitigation, and safeguard the nursery production system.

APHIS has allocated $62.975 M to fund 322 projects in 48 states, Guam, & Puerto Rico. ~ $13.5 M has been reserved for responding to pest and plant health emergencies throughout the year. USDA is funding ~70% of the more than 460 PPDMDPP proposals submitted.

Funding by Goal Area

1A – Enhance Plant Pest/Disease Analysis $2,057,174
1S – Enhance Plant Pest/Disease Survey $14,375,000
2 – Target Domestic Inspection Activities at Vulnerable Points $6,356,964
3 – Pest Identification and Detection Technology Enhancement $5,295,125
4 – Safeguard Nursery Production $2,079,119
5 – Outreach and Education $4,131,333
6 – Enhance Mitigation Capabilities $13,875,775

By my calculation (subject to error!), the total for projects on forest pests is ~$6.5 M – or a little over 10% of the total. The top recipient was survey and management of sudden oak death: ~$700,000 for research at NORS-DUC and NCSU plus detection efforts in nurseries of 14 states. Other well-funded efforts were surveys for bark beetles and forest pests (projects in 14 states); surveys for Asian defoliators (projects in 14 states); and outreach programs targetting the spotted lanternfly (10 states, plus surveys in California).

Three states (Iowa, Kentucky and Maryland) received funding for surveys targetting thousand cankers disease of walnut; two states (Kentucky and Maine) obtained funding for outreach about the risk associated with firewood. Funding for the Nature Conservancy’s “Don’t Move Firewood” campaign appears under the home state of its leader, Montana.

Massachusetts obtained funding for outreach re: Asian longhorned beetle. Ohio State received funding for developing a risk map for beech leaf disease.

Ten states received funding for no forest pest projects; I don’t know whether they sought funding for this purpose. These states are Arizona, Colorado, Florida, Hawai`i, Idaho, Minnesota, Nebraska, New Mexico, North Dakota, and Puerto Rico. The “National” funding category also contained no forest pest projects.

Looking at the overall funding level might give a somewhat skewed impression because several of the projects with total funding of ~ $500,000 are actually carried out by USDA agencies. These awards are listed under the state in which the USDA facility happens to be located. Nearly half this money ($213,000) goes to a project by an Agriculture Research Service unit in Delaware to study the efficacy of the biocontrol targetting emerald ash borer. Another $105,588 is allocated to detection of the SOD pathogen (Phytophthora ramorum) in irrigation water, undertaken – I think – at the ARS quarantine facility in Frederick, Maryland. A smaller project at a USFS research facility in Connecticut is studying egg diapause in the spotted lanternfly. The Delaware ARS unit is also pursuing biological control of the red-necked longhorn beetle (RNB) Aromia bungi, which attacks primarily stone fruits. Native to China and other countries in Asia, RNB has been intercepted in wood packaging by the U.S. and Europe; it has become established in Italy and Japan [Kim Alan Hoelmer, ARS, pers. comm.] The APHIS lab in Massachusetts is developing a light trap for detection of the Asian spongy moths Lymantria dispar.

I am intrigued that two states (Mississippi and Nevada) are conducting “palm commodity” surveys. Palms are important components of the environment in some states – although I am not certain these are the two most important!

As you might remember, I am also interested in some invaders other than forest pests. Washington has obtained $998,000 to support two projects integral to its efforts to find and eradicate the Asian (or Northern) Giant hornet. Oregon has obtained funding to carry out a survey for these hornets.

Cactus moth larvae feeding on prickly pear cactus; photo by Doug Beckers, via Flickr

I rejoice to see that the Florida Department of Agriculture continues efforts to deploy biocontrol agents targetting the cactus moth. The Agriculture Research Service is evaluating the establishment of biocontrol agents released to counter two highly invasive plants. Re: Brazilian peppertree, I don’t question the damage it has caused in southern Florida but I have grave concerns should the psyllid and thrips reach Hawai`i. I am most distressed to see that Hawaiian Division of Forestry and Wildlife and Department of Agriculture are actively pursuing deliberate introduction of the thrips. ARS is also searching for potential biocontrol agents targetting the invasive cogongrass (Imperata cylindrica). Penn State is working on registering a soil fungus native to North America, Verticillium nonalfalfae, as a biocontrol targetting the highly invasive tree of heaven (Ailanthus).

Phragmites invading Merkle Wildlife Sanctuary, Upper Marlboro, Maryland; photo by Alicia Pimental, (c) Chesapeake Bay Foundation

APHIS is pursuing biocontrol for “Roseau” cane scale. This situation presents a conflict of geographic regions because the plant to be controlled is Phragmites australis. Phragmites is highly invasive in the Mid-Atlantic, Northeast, and Great Lakes states . On the Mississippi delta it is considered important in maintaining wetlands crucial to protecting the Louisiana coast from rising seas.

Finally, USDA is pursuing management tools to contain the Box Tree Moth – a threat to the most widely planted ornamental shrub.

Posted by Faith Campbell

www.fadingforests.org

Climate Change + CO2 Levels – Can Scientists Include the Complexity in their Analyses?

Spruce budworm (*Choristoneura fumiferana*); photo by Jerald E. Dewey, USFS; via Bugwood; populations of several forest birds, including Cape May, Tennessee and Bay-Breasted warblers, become more numerous during budworm outbreaks

Now that Drs. Ziska and Aucott have educated us about the strong impact atmospheric CO₂ can have on both plants and phytopagous insects, I have asked the experts whether these interactions have been incorporated in the models scientists are using to forecast pest activity in American forests as the climate changes.

The answer is no.

bay-breasted warbler; photograph by Dave Inman at Presque Isle State Park, PA; via Flickr

Dr. Bethany A. Bradley, Co-Director, Northeast Climate Adaptation Science Center at the University of Massachusetts, says empirical models of species range shifts typically only use climate and sometimes other environmental factors (like soils or topography) as predictors of potential geography. Inclusion of demographic processes like how plant growth is affected by more or less water, CO₂, competition with other plants etc. would require a lot of data. It is currently impossible since there are tens of thousands of plant species interacting in the forests of eastern North America – and perhaps these factors have been analysed for only a hundred of them.

Mike Aucott points to the same difficulty: inclusion of CO₂ in models of the future populations of specific plants would be difficult since the impacts vary from species to species and are compounded by other factors such as soil nitrogen levels, moisture levels, temperature, presence of competing plants, etc.

Regarding insects, Dr. Aucott thinks it is clear that some orders, such as Lepidoptera, don’t fare as well when feeding on plants grown under elevated CO₂. He is not aware of efforts to model impacts of high CO₂ on specific insects or even orders or feeding guilds.

juniper geometer (inchworm); Dr. Tallamy says inchworms are hairless & good tasting – so sought by birds

Dr. Ziska concurs about the difficulties. Dr. Ziska asks why there is so little funding to study these issues, especially given their probable impact on human food supplies and health – as described in his blog and an opinion piece published in Scientific American two years ago.

I hope that scientists, decision-makers, readers of this blog … maybe even the media! – take into consideration these complexities, even if they cannot be defined.

Posted by Faith Campbell

For a detailed discussion of the policies and practices that have allowed these pests to enter and spread – and that do not promote effective restoration strategies – [but do not address climate or CO2 aspects] review the Fading Forests report at http://treeimprovement.utk.edu/FadingForests.htm

www.fadingforests.org

Australia Builds Capacity to Address Forest Pests

Australian Eucalypts; photo by John Turnbull via Flickr

I congratulate Australian scientists for bringing about substantial improvements of their country’s biosecurity program for forest pests. While it is too early to know how effective the changes will be in preventing new introductions, they are promising. What can we Americans learn from the Australian efforts? [I have previously praised South Africa’s efforts – there is much to learn there, too.]

Australia has a reputation of being very active in managing the invasive species threat. However, until recently biosecurity programs targetting forest pests were minimal and ad hoc. Scientists spent 30 years trying to close those gaps (Carnegie et al. 2022). Their efforts included publishing several reports or publications (listed at the end of the blog) and an international webinar on myrtle rust. Scientists are hopeful that the new early detection program (described below) will greatly enhance forest protection. However, thorough pest risk assessments are still not routinely conducted for forest pests. (Nahrung and Carnegie 2022).

The native flora of Australia is unique. That uniqueness has provided protection because fewer of the non-native insects and pathogens familiar to us in the Northern Hemisphere have found suitable hosts (Nahrung and Carnegie 2020). Also – I would argue – the uniqueness of this flora imposes a special responsibility to protect it from threats that do arise.

Only 17% of Australia’s landmass is covered by forests. Australia is large, however; consequently, these forests cover 134 million hectares (Nahrung and Carnegie 2020). This is the 7th largest forest estate in the world (Carnegie et al. 2022).

Australia’s forests are dominated by eucalypts (Eucalyptus, Corymbia and Angophora). These cover 101 million ha; or 75% of the forest). Acacia (11 million ha; 8%); and Melaleuca (6 million ha) are also significant. The forest also includes one million ha of plantations dominated by Pinus species native to North America (Carnegie et al. 2022). A wide range of native and exotic genera have been planted as amenity trees in urban and peri-urban areas, including pines, sycamores, poplars, oaks, and elms (Carnegie et al. 2022). These urban trees are highly valued for their ecosystem services as well as social, cultural, and property values (Nahrung and Carnegie 2020). Of course, these exotic trees can support establishment and spread of the forest pest species familiar to us in the Northern Hemisphere. On the positive side, they can also be used as sentinel plantings for early detection of non-native species (Carnegie et al. 2022 and Nahrung and Carnegie 2020).

Despite Australia’s geographic isolation, its unique native flora, and what is widely considered to be one of the world’s most robust biosecurity system, at least 260 non-native arthropods and pathogens of forests have established in Australia since 1885 (Nahrung and Carnegie 2020). [(This number is about half the number of non-native forest insects and pathogens that have established in the United States over a period just 25 years longer (Aukema et al. 2010).] As I noted, forest scientists have cited these introductions as a reason to strengthen Australia’s biosecurity system specifically as it applies to forest pests.

What steps have been taken to address this onslaught? For which pests? With what impacts? What gaps have been identified?

Which Pests?

Nahrung and Carnegie (2020) compiled the first comprehensive database of tree and forest pests established in Australia. The 260 species of non-native forest insect pests and pathogens comprise 143 arthropods, 117 pathogens. Nineteen of them (17 insects and 2 fungal species) had been detected before 1900. These species have accumulated at an overall rate of 1.9 species per year; the rate of accumulation after 1955 is slightly higher than during the earlier period, but it has not grown at the exponential rate of import volumes.

While over the entire period insects and pathogens were detected at an almost equal rate (insects at 1.1/year; pathogens at 0.9/year), this disguises an interesting disparity: half of the arthropods were detected before 1940; half of the pathogens after 1960 (Nahrung and Carnegie (2020). By 2022, Nahrung and Carnegie (2022) said that, on average, one new forest insect is introduced each year. Some of these recently detected organisms have probably been established for years. More robust surveillance has just detected them recently. I have blogged often about an apparent explosion of pathogens being transported globally in recent decades.

In a more recent article (Nahrung and Carnegie, 2022), gave 135 as the number of non-native forest insect pests. The authors don’t explain why this differs from the 143 arthropods listed before.

damage to pine plantations caused by *Sirex noctilio*; photo courtesy of Helen Nahrung

Eighty-seven percent of the established alien arthropods are associated with non-native hosts (e.g., Pinus, Platanus, Populus, Quercus, Ulmus) (Carnegie et al. 2022). Some of these have escaped eradication attempts and caused financial impact to commercial plantations (e.g., sirex wood wasp, Sirex noctilio) and amenity forests (e.g., elm leaf beetle, Xanthogaleruca luteola) (Carnegie and Nahrung 2019).

About 40% of the alien arthropods were largely cosmopolitan at the time of their introduction in Australia (Carnegie et al. 2022). Only six insects and six fungal species are not recorded as invasive elsewhere (Nahrung and Carnegie 2020). Of the species not yet established, 91% of interceptions from 2003 to- 2016 were known to be invasive elsewhere. There is strong evidence of the bridgehead effect: 95% of interceptions of three species were from their invaded range (Nahrung and Carnegie 2022). These included most of the insects detected in shipments from North America, Europe and New Zealand. These ubiquitous “superinvaders” have been circulating in trade for decades and continue to be intercepted at Australia’s borders. This situation suggests that higher interception rates of these species reflect their invasion success rather than predict it (Nahrung and Carnegie 2021).

I find it alarming that most species detected in shipments from Africa, South America, and New Zealand were of species not even recorded as established in those regions (Nahrung and Carnegie 2021; Nahrung and Carnegie 2022).

*Arhopalus ferus*, a Eurasian pine insect often detected in wood from New Zealand; photo by Jon Sullivan – in New Zealand; via Flickr

Half of the alien forest pests established in Australia are highly polyphagous. This includes 73% of Asian-origin pests but only 15% of those from Europe (Nahrung and Carnegie 2021). Nahrung and Carnegie (2022) confirm that polyphagous species are more likely to be detected during border inspections.

PATHWAYS

As in North America and Europe, introductions of Hemiptera are overwhelmingly (98%) associated with fresh plant material (e.g. nursery stock, fruit, foliage). Coleoptera introductions are predominantly (64%) associated with wood (e.g. packaging, timber, furniture, and artefacts). Both pathways are subject to strict regulations by Australia (Nahrung and Carnegie 2021).

Eradication of High-Priority Pests

Eight-five percent of all new detections were not considered high-priority risks. Of the four that were, two had not previously been recognized as threats (Carnegie and Nahrung 2019). One high-priority pest – expected to pose a severe threat to at least some of Australia’s endemic plant species – is myrtle rust, Austropuccinia psidii. Despite this designation, when the rust appeared in Australia in 2010, the response was confused and ended in an early decision that eradication was impossible. Myrtle rust has now spread along the continent’s east coast, with localized distribution in Victoria, Tasmania, the Northern Territory, and – in 2022, Western Australia. `

*Melaleuca quinquenervia* forest; photo by Doug Beckers via Wikimedia

There have been significant impacts to native plant communities. Several reviews of the emergency response criticized the haste with which the initial decision was made to end eradication (Carnegie and Nahrung 2019). (A review of these impacts is here; unfortunately, it is behind a paywall.)

A second newly introduced species has been recognized as a significant threat, but only after its introduction to offshore islands. This is Erythina gall wasp Quadrastichus erythrinae (Carnegie and Nahrung 2019). DMF Although Australia is home to at least one native species in the Erythrina genus, E. vespertilio,, the gall wasp is not included on the environmental pest watch list.

Four of the recently detected species were considered to be high impact. Therefore eradication was attempted. Unfortunately, these attempts failed in three cases. The single success involved a pinewood nematode, Bursaphelenchus hunanesis. See Nahrung and Carnegie (2021) for a discussion of the reasons. This means three species recognized as high-impact pests have established in Australia over 15 years (Nahrung and Carnegie (2021). In fact, Australia’s record of successful forest pest eradications is only half the global average (Carnegie and Nahrung (2019).

Carnegie and Nahrung (2019) conclude that improving early detection strategies is key to increasing the likelihood of eradication. They discuss the strengths and weaknesses of various strategies. Non-officials (citizen scientists) reported 59% of the 260 forest pests detected (Carnegie and Nahrung 2019). Few alien pests have been detected by official surveillance (Carnegie et al 2022). However, managing citizen scientists’ reports involves a significant workload. Futhermore, surveillance by industry, while appreciated, is likely to detect only established species (Carnegie and Nahrung 2019).

Interception Frequency Is Not an Indicator of Likelihood of Establishment

Nahrung & Carnegie (2021) document that taxonomic groups already established in Australia are rarely detected at the border. Furthermore, only two species were intercepted before they were discovered to be established in Australia.

Indeed, 76% of species established in Australia were either never or rarely intercepted at the border. While more Hemiptera species are established in Australia, significantly more species of Coleoptera are intercepted at the border. Among beetles, the most-intercepted family is Bostrichid borers (powderpost beetles). Over the period 2003 – 2016, Bostrichid beetles made up 82% of interceptions in wood packaging and 44% in wood products (Nahrung and Carnegie 2022). This beetle family is not considered a quarantine concern by either Australian or American phytosanitary officials. I believe USDA APHIS does not even bother recording detections of powderpost beetles. Nahrung and Carnegie (2021) think the high proportion of Bostrichids might be partially explained by intense inspection of baggage, mail, and personal effects. While Australia actively instructs travelers not to bring in fruits and vegetables because of the pest risk, there are fewer warnings about risks associated with wood products.

Nahrung & Carnegie (2021) concluded that interception frequencies did not provide a good overall indicator of likelihood of risk of contemporaneous establishment.

Do Programs Focus on the Right Species?

Although Hemiptera comprise about a third of recent detections and establishments, and four of eight established species are causing medium-to-high impact, no Hemiptera are currently listed as high priority forestry pests by Australian phytosanitary agencies (Nahrung & Carnegie (2021). On the other hand, Lepidoptera make up about a third of the high-priority species, yet only two have established in Australia over 130 years. Similarly, Cerambycidae are the most frequently intercepted forest pests and several are listed as high risk. But only three forest-related species have established (Nahrung and Carnegie 2020). (Note discussion of Bostrichidae above.).

Unlike the transcontinental exchanges under way in the Northern Hemisphere, none of the established beetles is from Asia; all are native to Europe. This is especially striking since interceptions from Asia-Pacific areas account for more than half of all interceptions Nahrung and Carnegie (2021).

Interestingly, 32 Australian Lepidopteran and eight Cerambycid species are considered pests in New Zealand. However, no forest pests native to New Zealand have established in Australia despite high levels of trade, geographic proximity, and the high number of shared exotic tree forest species (Nahrung and Carnegie 2020).

STRUCTURE OF PROGRAM

The structure of Australia’s plant biosecurity system is described in detail in Carnegie et al. (2022). These authors call the program “comprehensive” but to me it looks highly fragmented. The federal Department of Agriculture and Water Resources (DAWR,[recently renamed the Department of Agriculture, Fisheries, and Forestry, or DAFF) is responsible for pre-border (e.g., off-shore compliance) and border (e.g., import inspection) activities. The seven state governments, along with DAFF, are responsible for surveillance within the country, management of pest incursions, and regulation of pests. Once an alien pest has become established, its management becomes the responsibility of the land manager. In Australia, then, biosecurity is considered to be a responsibility shared between governments, industry and individuals.

Even this fragmented approach was developed more recently than one might expect given Australia’s reputation for having a stringent biosecurity system. Perhaps this reflects the earlier worldwide neglect of the Plant Kingdom? Carnegie and Nahrung (2019) describe recent improvements. Until the year 2000, Australia’s response to the detection of exotic plant pests was primarily case-by-case. In that year Plant Health Australia (PHA) was incorporated. Its purpose was to facilitate preparedness and response arrangements between governments and industry for plant pests. In 2005, the Emergency Plant Pest Response Deed (EPPRD) was created. It is a legally-binding agreement between the federal, state, and territorial governments and plant industry bodies. As of 2022, 38 were engaged. It sets up a process to implement management and funding of agreed responses to the detection of exotic plant pests – including cost-sharing and owner reimbursement. A national response plan (PLANTPLAN) provides management guidelines and outlines procedures, roles and responsibilities for all parties. A national committee (Consultative Committee on Emergency Plant Pests (CCEPP) works with surveys to determine invaded areas (delimitation surveys) and other data to determine whether eradicating the pest is technically feasible and has higher economic benefits than costs..

*Austropuccinia psidii* on *Melaleuca quinquenervia*; photo by John Tann via Flickr

Even after creation of EPPRD in 2005, studies revealed significant gaps in Australia’s post-border forest biosecurity systems regarding forest pests (Carnegie et al. 2022; Carnegie and Nahrung 2019). These studies – and the disappointing response to the arrival of myrtle rust – led to development of the National Forest Biosecurity Surveillance Strategy (NFBSS) – published in 2018; accompanied by an Implementation Plan. A National Forest Biosecurity Coordinator was appointed.

The forest sector is funding a significant proportion of the proposed activities for the next five years; extension is probable. Drs. Carnegie and Nahrung are pleased that the national surveillance program has been established. It includes specific surveillance at high-risk sites and training of stakeholders who can be additional eyes on the ground. The Australian Forest Products Association has appointed a biosecurity manager (pers. comm.)

This mechanism is expected to ensure that current and future needs of the plant biosecurity system can be mutually agreed on, issues identified, and solutions found. Plant Health Australia’s independence and impartiality allow the company to put the interests of the plant biosecurity system first. It also supports a longer-term perspective (Carnegie et al. (2022). Leading natural resource management organizations are also engaged (Carnegie, pers. comm.).

Presumably the forest surveillance strategy (NFBSS) structure is intended to address the following problems (Carnegie and Nahrung 2019):

Alien forest pests are monitored offshore and at the border, but post-border surveillance is less structured and poorly resourced. Australia still lacks a surveillance strategy for environmental pests.
Several plant industries have developed their own biosecurity programs, co-funded by the government. These include the National Forest Biosecurity Surveillance Strategy (NFBSS).

Some pilot projects targetting high risk sites were initiated in the early 2000s. By 2019, only one surveillance program remained — trapping for Asian spongy (gypsy) moth.

The states of Victoria and New South Wales have set up sentinel site programs. Victoria’s uses local council tree databases. It is apparently focused on urban trees and is primarily pest-specific – e.g., Dutch elm disease. The New South Wales program monitors more than 1,500 sentinel trees and traps insects near ports. This program is funded by a single forest grower through 2022.

Dr. Carnegie states: “With the start of the national forest biosecurity surveillance program in December 2022, the issues and gaps identified by Carnegie et al. 2022 are starting to be addressed. The program will conduct biosecurity surveillance specifically for forest pests and pathogens and be integrated with national and state biosecurity activities. While biosecurity in Australia is still agri-centric, a concerted and sustained effort from technical experts from the forest industry is changing this. And finally, the new Biosecurity Levy should ensure sustained funding for biosecurity surveillance.”

There is a separate National Environmental Biosecurity Response Agreement (NEBRA), adopted in 2012. It is intended to provide guidelines for responding, cost-sharing arrangements, etc. when the alien pest threatens predominantly the environment or public amenity assets (Carnegie et al. (2022). However, when the polyphagous shot hole borer was detected, the system didn’t work as might have been expected. While PSHB had previously been identified as an environmental priority pest, specifically to Acacia, the decision whether to engage was made under auspices of the the Emergency Plant Pest Response Deed (EPPRD) rather than the environmental agreement (NEBRA). As a result, stakeholders focused on environmental, amenity and indigenous concerns had no formal representation in decision-making processes; instead, industries that had assessed the species as a low priority (e.g., avocado and plantation forestry) did (Nahrung, pers.comm.).

Additional Issues Needing Attention

Some needs are not addressed by the National Forest Pest Strategic Plan (Carnegie et al. 2022) (Nahrung, pers. comm.):

1) The long-term strategic investment from the commercial forestry sector and government needed to maintain surveillance and diagnostic expertise;

2) Studies to assess social acceptance of response and eradication activities such as tree removal;

3) Studies to improve pest risk prioritization and assessment methods; and

4) Resolving the biosecurity responsibilities for pests of timber that has been cut and used in construction.

In 2019, Carnegie and Nahrung (2019) called for developing more effective methods of detection, especially of Hemiptera and pathogens. They also promoted national standardization of data collection. Finally, they advocated inclusion of technical experts from state governments, research organizations and industry in developing and implementing responses to pest incursions. They note that surveillance and management programs must be prepared to expect and respond to the unexpected since 85% of the pests detected over the last 20 years—and 75% of subsequently mid-to high-impact species established—were not on high-priority pest list. See Nahrung and Carnegie 2022 for a thorough discussion of the usefulness and weaknesses of predictive pest listing.

SOURCES

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

Carnegie A.J. and H.F. Nahrung. 2019. Post-Border Forest Biosecurity in AU: Response to Recent Exotic Detections, Current Surveillance and Ongoing Needs. Forests 2019, 10, 336; doi:10.3390/f10040336 www.mdpi.com/journal/forests

Carnegie A.J., F. Tovar, S. Collins, S.A. Lawson, and H.F. Nahrung. 2022. A Coordinated, Risk-Based, National Forest Biosecurity Surveillance Program for AU Forests. Front. For. Glob. Change 4:756885. doi: 10.3389/ffgc.2021.756885

Nahrung H.F. and A.J. Carnegie. 2020. NIS Forest Insects and Pathogens in Australia: Establishmebt, Spread, and Impact. Frontiers in Forests and Global Change 3:37. doi: 10.3389/ffgc.2020.00037 March 2020 | Volume 3 | Article 37

Nahrung, H.F. and A.J. Carnegie. 2021. Border interceps of forest insects estab in AU: intercepted invaders travel early and often. NeoBiota 64: 69–86. https://doi.org/10.3897/neobiota.64.60424

Nahrung, H.F. & A.J. Carnegie. 2022. Predicting Forest Pest Threats in Australia: Are Risk Lists Worth the Paper they’re Written on? Global Biosecurity, 2022; 4(1).

Posted by Faith Campbell

www.fadingforests.org

EAB: Why Quarantines Are Essential

area devastated by EAB; photo by Nathan Siegert, USFS

The emerald ash borer (EAB; Agrilus planipennis) is the most damaging forest insect ever introduced. In late June 2022 it was detected in Forest Grove, Oregon — 26 miles from Portland. This is the first confirmation of EAB on the West Coast – a jump of over 1,000 miles from outbreaks in the Plains states. The infested ash trees were immediately cut down and chipped (see Oregon Department of Agriculture website; full link at end of blog). See my earlier blog on EAB’s threat to ash-dominated riparian wetlands in Oregon.

ash-dominated swamp along the Willamette River in Oregon; photo by William Wyatt, ODF

Oregon has been preparing for the EAB:

The state finalized its response plan in March 2021; see reference at end of blog.
The state sought and received funds from USDA APHIS to initiate a biocontrol program. The funds were not from APHIS’ operational budget, but from the agency’s Plant Pest and Disease Management and Disaster Prevention Program (PPDMDPP) (Farm Bill money).
State and federal agencies have begun collecting seeds for resistance screening and a possible breeding program.

EAB: Why Quarantines Are Essential

As you might remember, in January 2021 APHIS dropped its federal regulations aimed at curtailing EAB’s spread via movement of wood and nursery plants. This shifted the responsibility for quarantines to state authorities. Instead, APHIS reallocated its funding to biological control. I raised objections at the time, saying the latter was no substitute for the former.

A new academic study shows that APHIS’ action was a costly mistake.

Hudgins et al. (2022; full citation at end of this blog) estimate EAB damage to street trees alone – not counting other urban trees – in the United States will be roughly $900 million over the next 30 years. These costs cannot be avoided. Cities cannot allow trees killed by EAB to remain standing, threatening to cause injury or damage when they fall.

ash fallen onto house in Ann Arbor, Michigan; photo courtesy of former mayor John Hieftje

The authors evaluated various control options for minimizing the number of ash street trees exposed to EAB. They assessed the trees’ exposure in the next 40 years, based on management actions taken in the next 30 years.

In their evaluation of management options, Hudgins et al. tried to account for the fact that the effect of management at any specific site depends on the effects of previous management. Additional complexity comes from the facts that the EAB is spread over long distances largely by human actions (i.e., movement of infested wood); and that biocontrol organisms also disperse.

They conclude that efforts to control spread at the invasion’s leading edge alone – as APHIS’ program did – are less useful than accounting for urban centers’ role in long-distance pest dispersal via human movement. Cities with infested trees are hubs for pest transport along roads. Hudgins et al. say that quarantine programs need to incorporate this factor.

Hudgins et al. concluded that the best management strategy always relied on site-specific quarantines aimed at slowing the EAB spread rate. This optimized strategy, compared to conventional approaches, could potentially save $585 million and protect an additional 1 million street trees over the next 40 years. They also found that budgets should be allocated as follows: 74-89% of funds going to quarantine, the remaining 11% to 26% to biocontrol.

In other words, a coherent harmonized quarantine program – either through reinstatement of the federal quarantine or coordination of state quarantines — could save American cities up to $1 billion and protect 1 million trees over several decades. Since street trees make up only a small fraction of all urban trees, up to 100 million urban ash trees could be protected, leading to even greater cost savings.

Unfortunately, such a coordinated approach seems unlikely. States continue to have very different attitudes about the risk. For example, Washington has no plans to adopt EAB regulations, despite it being detected in Oregon. To the north, Canada already has EAB quarantines and Hudgins et al. advise that they be maintained.

The authors recognize that quarantines’ efficacy is a matter of debate. Quarantines require high degrees of compliance from all economic agents in the quarantine area. Also they need significant enforcement effort. Some argue that meeting either requirement, let alone both, is unrealistic. However, under Hudgins et al.’s model, use of quarantines was always part of the optimal management method across a variety of quarantine efficiency scenarios. Again, these models point to allocating about 75% of the total budget to quarantine implementation. In all scenarios, reliance solely on biocontrol led to huge losses of trees compared to a combined strategy.

Hudgins et al. asked their model for optimal application of both quarantines and biocontrol agents. For example, quarantine enforcement could focus on limiting entry of EAB at sites that: 1) have many ash street trees, 2) currently have low EAB propagule pressure, but 3) are vulnerable to receiving high propagule influx from many sites. Seattle is a prime example of such a vulnerable city with many transportation links to distant cities with significant ash populations.

On the other hand, quarantine enforcement could strive to limit outward spread (emigration) of EAB from which high numbers of pests could be transported to multiple other locales, each with many street trees and low propagule pressure. These sites would be along the leading edge of the invasion and where the probability of long-distance pest dispersal is high.

Authorities should be prepared to adjust quarantine actions in response to changing rates and patterns of invasion spread.

Biocontrol agents should be deployed to sites with sufficient EAB density to support the parasitoids, especially sites predicted to be hubs of spread.

Hudgins et al. concede that they did not explicitly account for:

1) The impact of uncertainty regarding EAB spread on the model;

2) Alternative objectives that might point to other approaches, e.g., minimizing extent of invaded range, or reducing the number of urban and forest trees exposed to EAB;

3) Impacts of predators, such as woodpeckers, on EAB populations;

4) Synergistic impacts from climate change, which by exacerbating stress on ash trees will probably increase tree mortality from EAB infestations; and

5) Variation in management efficiency depending on communities’ capacities.

In the future, Hudgins et al. hope to test their model on other species to determine whether there is a predictable spatial pattern for all wood boring pests, that is, should quarantines always be focused on centers of high pest densities as probable sources of spread. Determining any patterns would greatly assist risk assessment and proactive planning.

dead ash near major road in northern Virginia; photo by F.T. Campbell

In an earlier study, Dr. Hudgins and other colleagues projected that by 2050, 1.4 million street trees in urban areas and communities of the United States will be killed by introduced insect pests – primarily EAB. This represents 2.1- 2.5% of all urban street trees. Nearly all of this mortality will occur in a quarter of the 30,000 communities evaluated. They predict that 6,747 communities not yet affected by the EAB will suffer the highest losses between now and 2060. However, they evaluated risks more broadly: the potential pest threat to 48 tree genera. Their model indicated that if a new woodboring insect pest is introduced, and that pest attacks maples or oaks, it could kill 6.1 million trees and cost American cities $4.9 billion over 30 years. The risk would be highest if this pest were introduced via a port in the South. I have blogged often about the rising rate of shipments coming directly from Asia to the American South

SOURCES

Hudgins, E.J., J.O. Hanson, C.J.K. MacQuarrie, D. Yemshanov, C.M. Baker, I. Chadès, M. Holden, E. McDonald-Madden, J.R. Bennett. 2022. Optimal emerald ash borer (Agrilus planipennis) control across the U.S. preprint available here: https://doi.org/10.21203/rs.3.rs-1998687/v2

Hudgins, E.J., F.H. Koch, M.J. Ambrose, B. Leung. 2022. Hotspots of pest-induced US urban tree death, 2020–2050. Journal of Applied Ecology

Members of this team published an article earlier that evaluated the threat from introduced woodborers as a group to U.S. urban areas; see E.J. Hudgins, F.H. Koch, M.J. Ambrose, B. Leung. 2022. Hotspots of pest-induced US urban tree death, 2020–2050. Journal of Applied Ecology

Oregon Department of Agriculture: https://www.oregon.gov/oda/programs/IPPM/SurveyTreatment/Pages/EmeraldAshBorer.aspx

Posted by Faith Campbell

www.fadingforests.org

West Coast Steps Up Efforts to Protect Ash

Oregon-ash dominated swamp in the Ankeny National Wildlife Refuge, Willamette Valley, Oregon; photo by Wyatt Williams, Oregon Department of Forestry

In April 2022 I blogged about efforts on the West Coast to prepare for arrival of the emerald ash borer (EAB).

That blog focused on Oregon ash (Fraxinus latifolia), which is an important component of riparian forests. I alerted you to the availability of ODA/ODF EAB 2018 Response Plan.

I also mentioned Oregon’s active participation in “don’t move firewood” campaigns.

California has long inspected incoming firewood. In 2021 it establishment of a state quarantine in response to APHIS ending the federal quarantine. Washington State operates a statewide trapping program for invasive insects but does not regulate firewood.

Contributions from the Tualatin Soil and Water Conservation District enabled the USDA Forest Service Dorena Genetic Resource Center to begin testing Oregon ash for resistance to EAB and related genetics work. Other funding came from the USFS Forest Health Protection program.

EAB has now been detected in Oregon — in the Willamette Valley! (See photo above, by Wyatt Williams) Concerned stakeholders have established a new newsletter to keep people informed and promote cooperative efforts.

The newsletter is “Ash across the West”.

The first issue of the newsletter provides the following information:

there are eight ash species in the West; all are vulnerable to the emerald ash borer (EAB)

Single-leaf ash (Fraxinus anomala) CA, NV, AZ, UT, NM, CO, WY

Fragrant ash (Fraxinus cuspidata) NV, AZ, NM, UT

Calif ash (Fraxinus dipetala) CA, NV, AZ, UT

Fresnillo (Fraxinus gooddingii) AZ

Gregg’s ash (Fraxinus greggii) AZ

OR ash (Fraxinus latifolia) WA, OR, CA

Chihuahuan ash (Fraxinus papillosa) AZ, NM, TX

Velvet ash (Fraxinus velutina) CA, NV, AZ, UT, NM, TX

EAB Risk Map for OR: based upon known occurrences of ash & corresponding human activities associated with known pathways of EAB introduction and establishment.
2022 status of the two field trials
- the Dorena Genetic Resource Center (DGRC): planted 600 seedlings from 27 families; 85% survival in 2022; controlling competing vegetation
- Washington State University Puyallup Research Center: planted seedlings from 26 of these families; 95% survival rate. Possible complication from a foliar disease.
Seedlings from 17 Oregon ash families (including 14 of those in the DGRC field trial) sent to Dr. Jennifer Koch (USFS) in Ohio) for EAB resistance/susceptibility testing.
Seed collections began in 2019; interrupted by COVID-19 in 2020 but resumed in 2021 and continue in 2022. Several consortia are involved in Oregon and Washington. In California and the other states, The Huntington Botanical Gardens will lead the collecting effort. Funding is from USFS Forest Health Protection. Seeds are stored for gene conservation; some are used for the field trials in Oregon and Washington and the initial EAB-resistance studies going on in Ohio.
Penn State Ash Genomic Project: Dr. Jill Hamilton is trying to create a ‘genomic passport’ for Oregon ash populations for use in establishing genotype-environment associations to inform seed transfer guidelines. If you would like to help Dr. Hamilton collect leaves for sampling, contact: Dr. Jill Hamilton at jvh6349@psu.edu

To help with seed collection, ash monitoring, documenting the importance of ash to various communities, and other activities; or to get on the mailing list for the newsletter, contact Richard Sniezko at Richard.sniezko@usda.gov

A video explaining the campaign to save Oregon ash is at https://youtu.be/uZmfLrxEA7g

Posted by Faith Campbell