forest pathogens – Page 19 – Center for Invasive Species Prevention

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

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

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

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

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

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

What Do We Know About Plant Imports?

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

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

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

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

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

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

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

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

Liebhold et al. 2012, relying on 2009 data, found that about 12 percent of incoming plant shipments had symptoms of pests – a rate more than 100 times greater than that for wood packaging — a pathway that has received far more international and U.S. regulatory attention for years. This finding is similar to that of a study in New Zealand, which found that 14 percent of consignments of plants were infested – primarily with pathogens (Epanchin-Niell 2017). Worse, though, Liebhold et al. found that a high percentage of pests associated with a plant shipment is not detected by the inspectors, although APHIS has disputed this finding.

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

Table 1. Overall number of pest detections recorded*

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

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

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

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

Table 2. Types of Pests Intercepted

Disease 34

Insect 290

Mite 20

Mollusk 23

Nematode 2

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

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

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

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

Principal Threats to North America’s Native Trees and Shrubs

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

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

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

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

FY2013: France, Canada, Belgium, China

FY2014: China, Canada, South Africa, Portugal

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

FY2016: Canada

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

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

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

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

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

Buxus 3 – all Canada – 2 insect, 1 mollusk

Camellia 2 – France – 1 disease, 1 mite

Chamaecyparis 1 – Canada; mite

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

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

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

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

Liriodendron 2 – Canada – insects

Magnolia grandifolia 1 – South Africa – insect

Opuntia 6 – Mexico – insects

Picea 7 – Canada – insects (primarily aphids)

Thuja 6 – Canada – insects

Tilia 2 – Canada – mollusk

What Else Do We Know?

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

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

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

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

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

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

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

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

Contact me to explore how we might work together.

Posted by Faith Campbell

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

SOURCES

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

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

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

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

Status of Phytopthoras in the United States & Europe: an update

tanoak killed by sudden oak death; Marin County, Calif. photo F.T. Campbell

Here is some interesting information from recent issues of the the California Oak Mortality Task Force’s bimonthly newsletter. I am updating my earlier blogs on the status of Phytophthoras and sudden oak death (SOD) in the United States and Europe.

The SOD pathogen (Phytophthora ramorum) persists in streams in the Southeast:

More than 600 samples were taken from streams or ponds in nine states (Alabama, Florida, Georgia, Mississippi, North Carolina, Pennsylvania, South Carolina, Tennessee, and Texas) during 2016. Ten of the samples were positive: seven from three streams in Alabama and three from one stream in Mississippi. Each of these had tested positive before; none was a new positive location. [March newsletter]

The disease continues to spread in Oregon and California:

During 2016 and early 2017, sudden oak death and tanoak mortality continued to intensify within the officially designated quarantine zone in southwest Oregon. So far, no new outbreaks have been detected outside the quarantine zone.

In Oregon, there is growing concern about the disease and the paucity of funds to address it. As a result, Oregon state Representative David Brock Smith and U.S. Senator Jeff Merkley have formed an Oregon Sudden Oak Death Task Force. The Task Force is developing a collaborative action plan to secure enough funding to contain the infestations of the NA1 genetic strain (the one widespread in Oregon and California) and to eradicate the EU1 lineage (this is the only known site where this strain is established in the forest in North America; see my blog from August 2015, which explains the significance of these strains.) [March newsletter]

In California, scientists have been surprised by the intensity of the disease in several parks on the eastern side of San Francisco Bay – an area that is drier than most forests that are infested. The severe drought of recent years has not prevented spread of the disease. Even more surprising, one park has very little California bay laurel – which is considered to be the primary source of infection. [March newsletter]

Native plant nurseries may be spreading various Phytophthoras (see my blog from last year here) or the presentations on “Phytophthora Detections in Native Plant Nurseries and Restoration Sites” posted here)

The National Ornamentals Research Site at Dominican University (NORS-DUC) sampled several types of native plant nurseries in fall 2016 to determine the extent of movement of Phytophthora species on plants they sell. Unfortunately, the report in the newsletter did not include results of the sampling. [January 2017]

CFDA photo of herbaceous plants with Phytophthora infection

Oregon and Washington authorities acted in response to the initial reports from the San Francisco area, and sampled nurseries in their states. They found a similarly high infestation rate in native plant nurseries in their states. Washington State University and Oregon State University have held several 2 ½-day workshops on “Preventing Phytophthora Contamination in Native Plant Nurseries and Restoration Sites”. [May newsletter]

For more information about Phytophthoras in native herbaceous plants in California, visit http://ucanr.edu/sites/sod6/Proceedings/Presentations_and_Posters/ and www.calphytos.org

Disease costs in England and Wales could top 1 billion dollars

Drake and Jones have estimated that damage by Phytophthora ramorum and P. kernoviae [link to Gallery] to non-extractive public use and non-use values at risk from uncontrolled spread of these diseases in England and Wales is £1.446 billion per year (approximately $US 1.82 billion). The greatest public value at risk (slightly more than one-third) is from an uncontrolled spread of these diseases to heritage gardens; lower risks are to the diseases’ spread to woodlands and heathlands. [March newsletter]

5) Ireland resembles Europe in numbers of Phytophthora species:

O’Hanlan and colleagues tested more than 11,000 samples from both “trade” environments (presumably, nurseries) and “non-trade” environments (presumably plantings or natural environments). They detected 19 species and 3 informally designated taxa of Phytophthora, including 8 new records for Ireland. Thus, Ireland’s situation is similar to that in Europe more broadly – a study last year by Junker and colleagues report the detection of 15 Phytophthora species in two commercial woody ornamental nurseries [link to blog about Phythophs in Europe] In Ireloand, P. ramorum was found on 30 hosts; P. syringae on 6 hosts; P. kernoviae on 3 hosts. Phytophthora species were most frequently detected on rhododendrons – (12 Phytophthora species). [January newsletter]

SOURCES

Drake, B. and Jones, G. 2017. Public Value at Risk from Phytophthora ramorum and Phytophthora kernoviae Spread in England and Wales. Journal of Environmental Management. 191: 136–144.

Junker, C., Goff, P., Wagner, S., and Werres, S. 2016. Occurrence of Phytophthora in commercial nursery production. Plant Health Progress. 17:64-75.

O’Hanlon, R.; Choiseul, J.; Corrigan, M.; Catarame, T.; and Destefanis, M. 2016. Diversity and Detections of Phytophthora Species from Trade and Non-Trade Environments in Ireland. EPPO Bull. 46: 594–602. DOI: 10.1111/epp.12331.

Posted by Faith Campbell

Lobby House and Senate Agriculture Appropriations Subcommittees in support of increasing funding for two crucial APHIS programs

On May 19 I posted a blog asking you to lobby Congress in support of maintaining current funding levels for two programs aimed to eradicating or containing tree-killing pests. These are the “tree and wood pest” and “specialty crop” programs operated by the USDA Animal and Plant Health Inspection Service (APHIS).

At the time, I had not seen the President’s budget proposal. Now I have seen the President’s budget – and, as anticipated, it calls for steep cuts in the “tree and wood pest” program. The President calls for cutting this program by 44% — from $54 million to $30 million. Specifically, the Asian longhorned beetle (ALB) eradication program would be cut by approximately 50% — $20.770. The emerald ash borer (EAB) containment program would also be cut by half — $3.127 million.

The President’s budget justifies these severe cuts by saying that states, localities, and industries benefit from eradication or containment of the ALB and EAB, so they should help pay for the containment program. The Office of Management and Budget states that other beneficiaries should pay 50% of program costs.

For whatever reason, the budget does not propose to cut APHIS’ efforts to prevent spread of the European gypsy moth.

In reality, states, localities, and industries are very unlikely to make up the difference in funding. We should remind the Congress that already, local governments across the country are spending more than $3 billion each year to remove trees on city property killed by non-native pests. Homeowners are spending $1 billion to remove and replace trees on their properties and are absorbing an additional $1.5 billion in reduced property values and reducing the quality of their neighborhoods. (See Aukema et al. article listed below.)

ash tree killed by EAB; Ann Arbor, MI; courtesy of Major Hefje

Cuts of the size proposed by the President’s budget will undermine the programs completely. Such a result is particularly alarming given the record of success in eradicating ALB populations – when resources are sufficient; and the urgent need to complete eradication programs in Massachusetts, New York, and Ohio. As I said in May, the ALB program has succeeded in eradicating 85% of the infestation in New York. (APHIS has just announced that a section of the borough of Queens is free of ALB.) However, the infestation in Massachusetts has been only 34% eradicated; that in Ohio has been only 15% eradicated. Crippling the program now will expose urban and rural forests throughout the Northeast to severe damage by this insect, which attacks a wide range of species.

The importance of continuing the EAB containment program has been re-emphasized by scientists’ recent determination that EAB can attack commercial olive trees as well as all species of ash.

The budget also does not recognize the need for APHIS to expand its program to address other tree-killing pests, including the spotted lanternfly, and polyphagous and Kuroshio shot hole borers.The shot hole borers attack hundreds of tree species, including California sycamore, cottonwoods, and several oaks. Many known hosts are either found across the Southeast, or belong to genera that are found across the Southeast – so the threat is national. The spotted lanternfly – now established in Pennsylvania — threatens agriculture – especially grapes, apples, plums, cherries, peaches, nectarines, apricots, and almonds; as well as oak, walnut, poplar, and pine trees.

More than 30 tree-attacking pests have been introduced in recent years. Additional species from these introductions might also require APHIS-led programs; one example is the velvet longhorned beetle.

velvet longhorned beetle; bugwood.org

The budget calls also for a 6% cut on the “specialty crops” program – from $158 million to $148 million. It is not clear how such a reduction would affect APHIS’ program to prevent spread of the sudden oak death (SOD) via movement of nursery stock [link to earlier blogs & Gallery]. The SOD program has been funded at approximately $5 million in recent years.

Finally, additional challenges lie ahead because it is likely that new tree-killing pests will be introduced with rising import volumes. Each year, border inspectors detect more than 800 import shipments with pests infesting the crates and pallets. These represent a small proportion of the actual risk; one analysis estimated that 13,000 shipments with infested packaging enter the country each year. APHIS must have sufficient resources to respond when the inevitable newly introduced pests are detected.

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

SOURCE

Aukema, J.E., B. Leung, K. Kovacs, C. Chivers, K. O. Britton, J. Englin, S.J. Frankel, R. G. Haight, T. P. Holmes, A. Liebhold, D.G. McCullough, B. Von Holle.^. 2011. Economic Impacts of Non-Native Forest Insects in the Continental United States PLoS One September 2011 (Volume 6 Issue 9)

Posted by Faith Campbell

Support Adequate Funding for APHIS Tree-Pest Programs

Congress is now considering funding for various agencies and programs for Fiscal Year 2018 – which begins on October 1. Please contact your Representative and Senators and urge them to support adequate funding for key programs managed by the USDA Animal and Plant Health Inspection Service (APHIS). These are essential for keeping the nation’s forests healthy by preventing introduction and spread of invasive pests. While I would much prefer to increase funding for these programs, that is impossible at this time. So I suggest that you support maintaining last year’s funding levels for two budget“lines” under the USDA APHIS Plant Health program: $54 million for the “Tree and Wood Pests” line and $156 million for the “Specialty Crops” line.

I have blogged often about the impacts of non-native insects and pathogens inthe United States — which are enormous. (See Lovett et al. 2016 for a summery.) As new pests are introduced and established pests spread, these costs will only continue to rise.

Moreover, since 1975, U.S. imports (excluding petroleum products) have risen almost six times faster than APHIS and Customs and Border Protection’s staff capability to inspect them. As a result of this and other prevention failures, such as insufficiently protective regulations, more than a dozen new plant pests are detected in the United States each year. Since the beginning of the 21^st Century, at least 20 wood–boring beetles have been detected here, including:

Redbay ambrosia beetle / laurel wilt disease;
Sirex woodwasp;
Goldspotted oak borer;
Walnut twig beetle and thousand cankers disease ;
Soapberry borer;
Polyphagous & Kuroshio shot hole borers; and
Velvet longhorned beetle.

Another dozen tree-killing pests that are not wood borers have also been detected, including Spotted lanternfly.

APHIS Programs Target only a Few of the Damaging Pests in the Country

At least in part because of inadequate funding, APHIS currently funds comprehensive programs targeting only four of the dozens of already- or potentially-serious tree-killing pests already in the country: gyspy moth (both European and Asian); Asian longhorned beetle; emerald ash borer; and sudden oak death.

APHIS also provides limited assistance to programs on other pests through grants under the Section 10007 of the 2014 Farm Bill. One example is research to determine host ranges and possible control method for the polyphagous and Kuroshio shot hole borers. However, these funds have not been sufficient to support comprehensive suppression or eradication programs despite the threat posed by these two shot-hole borers. They threaten to kill 26 million trees – more than a third of the trees growing in urban areas in California’s Inland Empire, Coastal Southern California, and Southwest Desert. Absent an active APHIS program to develop effective control measures, the municipalities and homeowners of these regions will be forced to absorb an estimated $36.2 billion (the costs of removing and replacing dead and dying trees) if they want to maintain valuable urban forest canopy.

willow killed by Kuroshio shot hole borer

in Tijuana River estuary, California

photo by John Boland

The shot-hole borers might also threaten trees across the American South. Box elder, sweetgum, and tree of heaven are reproductive hosts for the polyphagous shot hole borer; all are widespread in southern forests. California species of sycamore, oak, and willow are also reproductive hosts; other trees in these genera, which grow widely across the U.S., might also be vulnerable to the shot hole borers.

APHIS also has devoted Section 10007 funds to the spotted lanternfly, which is found in southeastern Pennsylvania. This insect feeds on several crop trees as well as oak, walnut, poplar, and pine trees. Pennsylvania authorities cannot complete eradication of this pest without additional federal funding – which so far is uncertain.

APHIS has helped with trace-forwards to find furniture infested by the velvet longhorned beetle, but has not adopted a program targetting this species in the several states where it appears to be established.

As these examples illustrate, even maintaining current funding levels means that several damaging non-native insects and pathogens continue to spread without a meaningful federal response. Any cuts would only exacerbate the failure of APHIS’ program to protect our forests from non-native insects and pathogens.

Remember, too, that additional introductions are likely in coming years. According to one study, perhaps 35 shipping containers entering the country each day carry damaging pests.

Unloading largest container ship to visit a U.S. East Coast port – “Cosco Development”; Savannah, GA May 12, 2017; F.T. Campbell

At the same time, we cannot afford for APHIS to reduce its ongoing programs in order to address the other invaders. The Asian longhorned beetle eradication program, at a cost of $35 – $40 million per year, has succeeded in eradicating 85% of the infestation in New York. (APHIS has just announced that a section of the borough of Queens is free of ALB.) However, the infestations in Massachusetts and Ohio still threaten to spread further into the forests. The $5 – $6 million per year allocated to the gypsy moth appears to be adequate, but APHIS must be prepared to eradicate any newly detected outbreaks, especially of the Asian gypsy moth on the west coast.

APHIS’ emerald ash borer program has received $7 million per year. To reduce future costs, the agency has cut back its regulatory program, so that it enforces regulations only at the infestation’s leading edge. In affected states, APHIS will continue surveys in unregulated areas, outreach, and coordination. These changes, taken together, undermine efforts to prevent the beetle’s spread to the vulnerable rural and urban forests in North Dakota, Oregon, and other states. APHIS is emphasizing production and dispersal of biocontrol agentsrather than regulatory measures

The sudden oak death program – targeting the pathogen Phytophthora ramorum — is under the “Specialty Crops” funding line. This must also be maintained at current levels because SOD threatens such important eastern forest tree species as northern red, chestnut, white, and pin oaks; sugar maple; and black walnut. APHIS regulates movement of nursery stock which could transport this pathogen from the West coast to vulnerable areas in the East. It was learned recently that APHIS needs to add the genus Magnolia to the “filthy five” group which is subject to the most careful regulation.

Whom to Contact

Please ask your Senators and Representative to support maintaining – or even increasing – funding for these APHIS programs. Your contact is especially important if you are represented by one of the members of the House or Senate Appropriations Committee’s Subcommittees on

Agriculture:

House:

* Robert Aderholt, Alabama, Chairman

* Kevin Yoder, Kansas

* Tom Rooney, Florida

* David Valadao, California

* Andy Harris, Maryland

* David Young, Iowa

* Steven Palazzo, Mississippi

* Sanford Bishop, Georgia, Ranking Member

* Rosa DeLauro, Connecticut

* Chellie Pingree, Maine

* Mark Pocan, Wisconsin

Senate:

John Hoeven, North Dakota

Thad Cochran, Mississippi

Mitch McConnell, Kentucky

Susan Collins, Maine

Roy Blunt, Missouri

Jerry Moran, Kansas,

Marco Rubio, Florida

Jeff Merkley, Oregon

Diane Feinstein, California

Jon Tester, Montana

Tom Udall, New Mexico

Patrick Leahy, Vermont

Tammy Baldwin, Illinois

Sources

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

http://onlinelibrary.wiley.com/doi/10.1890/15-1176/full

Additional recent sources of information on tree-killing pests not being addressed by APHIS:

Article about the damage caused by the goldspotted oak borer:

http://westernipm.org/index.cfm/ipm-in-the-west/natural-areas/gold-spotted-oak-borer-threatens-oak-woodlands-and-ecosystems-across-southern-california/?keywords=GSOB

Videos:

GSOB at Irvine Regional Park in OC

https://www.youtube.com/watch?v=eCRVmP5KmW0&feature=youtu.be

Goldspotted Oak Borer video

https://www.youtube.com/watch?v=In2e5atd3ZY&feature=youtu.be#t=13.3989831

The Los Angeles Times has published two recent articles about the shot hole borers at

http://www.latimes.com/local/california/la-me-dying-urban-trees-20170403-story.html

and

http://www.latimes.com/local/california/la-me-trees-change-20170427-story.html

Posted by Faith Campbell

USDA needs to utilize the NAPPRA Process to Prevent New Introductions

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

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

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

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

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

dogwood anthracnose; Robert L. Anderson. courtesy of bugwood.org

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

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

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

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

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

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

Sources

Posted by Faith Campbell

Using politics to protect our trees from non-native insects & pathogens

As we know, North America’s trees are under severe threat from a growing number of non-native insects, pathogens, nematodes, etc. (For lengthy descriptions of the threat, substantiated by source citations, read the Fading Forests reports here; or check out a recent policy brief here; or short descriptions; or from my earlier blogs.)

I hope we all agree on broad goals in our efforts to counter this threat. I suggest those goals – broadly speaking, can be summarized as

Preventing additional introductions to the greatest extent possible
Detecting new introductions quickly, initiating rapid & effective eradication or containment actions
Minimizing the risk of pest spreading from one state to others
Implementing programs aimed at restoring pest-depleted tree species to forests

America decides what issues government agencies will address through politics – the squeaky wheel gets the grease. We care about the pest threat to trees … so it is up to us to persuade political players to support programs structured to achieve these goals.

There are several approaches to engaging politicians. These should be pursued simultaneously and in a coordinated way. And we must persevere — asking politely but persistently for specific actions. Success is not achieved by one-time actions, but by continuing effort.

What Can We Do?

We can ask our state’s Governor to

Immediate actions

Communicate to the USDA Secretary the need to amend policies & regulations
Communicate with governors of other states with severe tree pest issues to ask them to support approaches to USDA & Congress
Put forest pest issue on the agenda of National Governors’ Association
Communicate with our state’s Congressional delegation and ask them to pressure USDA Secretary to amend policies and regulations
Communicate to the media both his/her concern about tree pest threats and proposed solutions.

Longer-term actions

Ask our state’s Congressional delegation to support proposed amendments to the 2019 Farm bill (see below)

We can ask our state’s agricultural and forestry agency heads to

Ask their national associations to support proposals to USDA Secretary & Congress. These associations include
- National Association of State Departments of Agriculture (NASDA)
- National Association of State Foresters (NASF) or its 3 regional groups – Northeastern Area Association of State Foresters, Southern Group of State Foresters, Council of Western State Foresters
Communicate to the media both the agency’s concern about tree pest threats and proposed solutions.

learning about forest pests (laurel wilt)

We can also act directly.

Ask mayors and officials of affected towns and counties to

Push proposals at regional or National Conference of Mayors or National Association of Counties
Instruct local forestry staff to seek support of local citizen tree care associations, regional and national associations of arborists, Arbor Day & “Tree City” organizations, Sustainable Urban Forest Coalition, etc.
Reach out to local media with a message that includes descriptions of policy actions intended to protect trees — not just damage caused by the pests
Ask stakeholder organizations of which we are a member or with whom we have contacts to speak up on the issue and support proposed solutions:
- USDA Forest Service
- State forestry divisions
- Professional/scientific associations
- Wood products industry
- State departments of agriculture
- State phytosanitary officials
- Forest landowners
- Environmental NGOs
- Urban tree advocacy & support organizations

Encourage like-minded colleagues in other states to press the agenda with their state & federal political players, agencies, & media.

Communicate to the media both your concern about tree pest threats and proposed solutions.

Our goal is to create a “parade” – the impression of a groundswell demanding action that politicians will want to join. (Usually, they like to appear to “lead” the parade!). Note what was said by a real “Washington insider”, Arthur Brooks, President of the American Enterprise Institute. “If you want to influence leaders, sometimes you have to start a parade.” Quoted in the Washington Post 2/10/17

What Should We Tell All These People, Specifically?

What should be the content of our message to these potential allies? I suggest a coordinated package. However, you might feel more comfortable selecting a few to address each time you communicate with a policymaker. Just choose those you think are most urgent, those you feel most passionate about, or those on which you have the most expertise. There is something for everyone below!

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

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

Importers switch from packaging made from solid wood (e.g., boards and 4”x4”s) to packaging made from other materials, e.g., particle boards, plastic, metal …
This can be done by

— Persuading APHIS to initiate a rulemaking to require importers to make the shift. This can be done – although international trade agreements require preparation of a risk assessment that justifies the action because it addresses an identified risk (see my earlier blogs about wood packaging).

— Creating voluntary certification programs and persuade major importers to join them. One option is to incorporate non-wood packaging into the Department of Homeland Security Bureau of Customs and Border Protection’s (CBP) existing Customs-Trade Partnership Against terrorism (C-TPAT) program.

Tighten enforcement by penalizing shipments in packaging that does not comply with the current regulations

— Persuade CBP and/or USDA to end current policy under which no financial penalty is imposed until a specific importer has been caught five times in a single year with non-compliant wood packaging. APHIS has plenty of authority to penalize violators.

The Plant Protection Act [U.S.C. §7734 (b) (1)] provides for fines ranging from $50,000 for an individual up to $1 million for multiple, willful violations. These penalties can be imposed by the Secretary of Agriculture after a hearing – but without going through a trial. So far, the Secretary has not used this power to deter violations.

Restrict imports of woody plants that are more likely to transport pests that threaten our trees

— In 2011, APHIS adopted regulations giving it the power to temporarily prohibit importation of designated high-risk plants until the agency has carried out a risk assessment and implemented stronger phytosanitary measures to address those risks. Plants deserving such additional scrutiny can be declared “not authorized for importation pending pest risk assessment,” or “NAPPRA”. APHIS has proposed two lists of plant species under this authority. The second list was proposed nearly 4 years ago, but it has not been finalized so imports continue. APHIS should revive the NAPPRA process and utilize prompt listing of plants under this authority to minimize the risk that new pests will be introduced.

— APHIS should finalize amendments to the “Q-37” regulation (proposed nearly 4 years ago) that would establish APHIS’ authority to require foreign suppliers to implement integrated programs to minimize pest risk. Once this regulation is finalized, APHIS could begin negotiating agreements with individual countries to adopt systems intended to ensure pest-free status of those plant types, species, and origins currently considered to pose a medium to high risk.

— APHIS & USDA Foreign Agricultural Service should strengthen surveillance in foreign source countries for pests likely to attack North American trees, using such strategies as “sentinel trees” planted in botanical gardens.

Strengthen early detection/rapid response programs by

— Providing adequate funds to federal & state detection and rapid response programs. The funds must be available for the length of the eradication program – which often requires a decade or more. The current “emergency” funds available as transfers from the Commodity Credit Corporation usually are cut off after only 1 – 2 years.

— Better coordinate APHIS, USFS, state, & tribal surveillance programs.

— Engage tree professionals & citizen scientists more effectively in surveillance programs.

Enact Amendments to the 2019 Farm Bill to strengthen programs aimed at protecting North American trees from non-native insects and pathogens

— Stakeholders meeting under the auspices of several coalitions are considering what amendments to the Farm Bill could be advocated for the purpose of protecting our trees from non-native pests. Proposals under consideration would address such issues as

>> Strengthening APHIS’ pest-prevention mandate (which currently is conflated with a competing mandate to facilitate trade)

>> Providing increased and more reliable funding for detection, rapid response, and long-term restoration efforts

>> Providing incentives to importers to adopt pest-prevention programs beyond current legal requirements governing wood packaging materials

I will provide additional information about these proposals in coming weeks.

SOURCES

Posted by Faith Campbell

Sudden Oak Death – the situation worsened in 2016

oak tree infected by P. ramorum; photo by Bruce Moltzan, USDA Forest Service

Sudden oak death (caused by the pathogen Phytophthora ramorum) might seem to be an old story – after all, mortality of oaks and other trees in the San Francisco Bay area was first noted 20 years ago. See the information here or here or my earlier blogs at http://nivemnic.us/2016/04/; http://nivemnic.us/2016/02/; http://nivemnic.us/2015/08/; and http://nivemnic.us/2015/07/

Unfortunately, the story is very much alive – and the situation is getting worse.

In 2016, infected trees were detected in new sites in California. See the November 2016 California Oak Mortality Task Force (COMTF) Newsletter here.

Based on a “SOD Blitz” using surveys by local people, (summarized in the COMTF newsletter), the pathogen has expanded substantially in areas that received adequate moisture in winter/spring 2016.

For the first time, ramorum was detected in San Luis Obispo County. This is the southern-most county with wildland detections in the state. Nor is it a small single outbreak; the SOD Blitz identified the pathogen on California bay laurel at approximately eight locations throughout the county. The infestations appear to be recent, since oaks were not found to be infected.
New outbreaks were detected along the central and southern coasts of Mendocino County (north of the San Francisco Bay area).

Infected trees were also detected in areas where the pathogen activity had subsided as a result of the state’s recent drought, including:

Northern and central Sonoma County and Napa Valley.
Infection rates have increased in Marin County.
San Francisco’s Golden Gate Park and the San Francisco Botanical Garden.
Infection rates in Big Sur in Monterey County increased by 27%.
There have been sharp increases in infection in some areas that previously were marginally affected, g., western San Mateo and Santa Cruz counties.

In Oregon, the area infested by sudden oak death has been expanding since at least 2014. In 2015, 18 new outbreaks were detected. In 2016, another 65 new outbreaks were found. All are within the state’s quarantine area (which was doubled in size in 2015; it now covers nearly one-third of Curry County). Oregon officials believe this increase is a consequence of the combination of a wet/mild winter and spring and the establishment of the state-designated “Generally Infested Area” (58 square miles) where disease treatment is no longer required.

EU1 strain in forests in Oregon

Oregon has determined that the presence of the EU1 lineage of Phytophthora ramorum is more widespread than originally known. (My blog of August 2015 described the initial finding of a single tanoak infected by this lineage in 2015 and the importance of finding a genetically different form of the pathogen in the wild in North America.) As of late 2016, scientists had identified a second outbreak of the EU1 pathogen – on 1 grand fir seedling and 12 tanoaks. Additional trees might be infected; results were pending for another grand fir and 11 additional tanoaks. This outbreak was detected through follow-up on a stream bait detection. This new EU1 infestation is located between the 2015 EU1-positive tanoak site and a now closed ornamental nursery, which, based on molecular testing, was the probable source of the 2015 EU1 infestation. The new EU1 infestation was top priority for treatment in the fall; these activities have already begun (Information from Sarah Navarro, pathologist for Oregon Department of Forestry).

While sudden oak death has already killed more than 3 million tanoaks reaching from Monterey County north into Oregon, large areas occupied by tanoaks are still not infested. It is important to slow the spread of this pathogen.

The spreading devastation is particularly galling since scientists have shown than an aggressive, well-funded containment effort begun in 2002 could have measurably slowed spread of the disease. See reference and news report below.

References

https://www.sciencedaily.com/releases/2016/05/160502161111.htm?utm_source=feedburner&utm_medium=email&utm_campaign=Feed%3A+sciencedaily%2Fplants_animals%2Finvasive_species+%28Invasive+Species+News+–+ScienceDaily%29

Cunniffe, N.J., R.C. Cobb, R.K. Meentemeyer, D.M. Rizzo, and C.A. Gilligan. Modeling when, where, and how to manage a forest epidemic, motivated by SOD in Calif. PNAS, May 2016 DOI: 10.1073/pnas.1602153113

Lack of Regulation and Funding Shortfalls Raise Probability of Pests’ Spread

OLYMPUS DIGITAL CAMERA — Photo by John Boland – willows killed by Kuroshio shot hole borer, Tijuana River, California

The polyphagous (PSHB) and Kuroshio (KSHB) shot hole borers are causing havoc in riparian and planted landscapes in four counties in southern California and are spreading north. (For current information go here or here .

As I described in a blog last July, the two insects are known to attack hundreds of tree species; at least 40 are reproductive hosts. Trees known to support PSHB include box elder, big leaf maple, California sycamore, willows, cottonwoods, and several California oaks. The insect-fungi combinations threaten more than a third of trees in the urban forests in southern California, with a cost for the trees’ removal and replacement estimated at $36 billion. Costs and hosts are discussed more fully in the July blog linked to above.

The High Cost of Management

Already, UC Irvine has spent close to $2 million to manage trees on campus that have been attacked.

Orange County has both polyphygous and Kuroshio shot hole borers. One agency – Orange County parks – has spent $1.7 million on shot hole borer surveys, tree inventory, public outreach materials, staff training, and some research. The parks agency is trying to engage other county agencies, such as Public Works and Waste & Recycling to get their help. For example, Public Works is putting together a tree ordinance with enforceable provisions.

While scientists have not yet published their analysis of the vulnerability of forest areas in other parts of the country, we do know that some reproductive hosts are widespread across the country — box elder, sweet gum, Japanese wisteria, and tree of heaven. Less is known about the hosts for Kuroshio shot hole borer. For a full list of known hosts, visit the two sources linked to in the first paragraph.

How Agencies Should Respond to this Threat

The shot hole borers and associated fungi clearly represent serious threats to urban, rural, and wildland forests across California and probably much of the rest of the country. Clearly it is important that we:

Increase our understanding of these insects and their associated fungi – including their possible geographic and host ranges;
Use this evolving understanding to develop detection tools; and
Use this evolving understanding to develop methods to slow their spread or to protect trees.

So what is being done? Individuals – academics; staff of local, state, and federal agencies; and concerned conservationists – are working hard. But they get little support from state or federal phytosanitary agencies.

The Need for New State and Federal Regulations

I have written earlier about the refusal of California Department of Food and Agriculture to either designate the polyphagous and Kuroshio shot hole borers as quarantine pests [] or to regulate movement of firewood – one of the major pathways for spread of the insects.

Nor has USDA APHIS designated the insects and their fungi as quarantine pests. The apparent explanation for the agency’s inaction is the considerable taxonomic confusion about the beetles and the possibility that the insects are already established elsewhere in the U.S. In addition, since the two shot hole borers are currently known only from California, APHIS is unlikely to take action unless California does. However, there is no legal requirement that APHIS defer to the state on this matter.

The Results of Funding and Regulatory Shortfalls

Both CDFA and APHIS are providing some funds to support research and development. Research on detection, spread, and possible biocontrols — for the insects or fungi — have received a total of $385,000 in FY16 and $419,549 in FY17 from a grant program operated under the USDA Plant Pest and Disease Management and Disaster Prevention Program (Farm Bill Sec. 10007). Still, the principal investigators and affected county, state, and federal agencies are scrambling to fill funding gaps – projects that will improve our understanding and put forward practical advice.

The San Diego Association of Governments (SANDAG) and Natural Communities Coalition (NCC) of Orange County are supporting research by Akif Eskalen and Shannon Lynch of UC Riverside on both (a) biocontrol using endophytes naturally occurring in various host tree species and (b) models to predict the disease’ behavior in native vegetation. Dr. Eskalen and Dr. John Kabashima of Orange County Cooperative Extension are seeking funds to support additional work on outreach and extension for advisors, land managers, master gardeners and homeowners.

Santa Barbara County officials – where at least one of the shot hole borer species was recently detected – are struggling to fund an expanded trap program to detect the insects. The CDFA does have traps deployed but UC Santa Barbara is considering launching a trapping program in riparian areas (where many of the host trees play especially important ecological roles). Officials are still not certain which species of insect is present (they think it is KSHB) and whether the beetles are carrying the typical fungal complex or something novel.

In the past, some of the work on the shot hole borers has been funded by associations of avocado growers. However, it is now clear that the beetle attacks only avocado tree branches, so it does not kill the tree. No longer facing a dire threat to their industry, the avocado commission is no longer funding research work on this pest-disease complex.

The experts – Dr. Eskalen for the fungi and his colleague Dr. Richard Stouthamer for the insects – have no funds to process samples sent to their laboratories for the confirmation of the beetles and fungi. They might soon have to charge fees for each sample – thereby discouraging collections that track each species’ spread and find new introductions.

In the absence of CDFA designation of the shot hole borers as regulated pests, neither state nor county agencies have a firm foundation on which to base regulations to curtail movement of firewood, green waste, or other pathways by which these pests can be spread to new areas.

Conservation Agencies are Cobbling Together Responses As Best They Can

Southern California staff of the California Department of Fish and Wildlife agency, responding to the damage caused by the Kuroshio shot hole borer in the Tijuana River estuary (described here and here), have formed a coalition to develop strategies for natural resource and urban forestry settings and ensure coordination. Natural resource agencies have access to some funding sources, such as Natural Communities Coalition (NCC) grants and funding for management of invasive species in protected habitats.

Southern California staff of the U.S. Fish and Wildlife Service are seeking grants from internal agency sources – citing the threat to riparian-dependent wildlife, especially the endangered Least Bell’s vireo.

Santa Monica National Recreation Area and the three National forests in the vicinity – the Angeles, Cleveland, and San Bernardino National forests – have taken actions that should help prevent the shot hole borers’ introduction via firewood. Santa Monica Recreation Area does not allow wood fires, only charcoal (this action probably is in response to the high fire danger in the area rather than the pests specifically). The National forests’ webpages on camping include a graphic with the statements “Buy It Where You Burn It” and “Be aware that firewood can harbor insects and diseases; transporting it can move these pests to new locations.” (See my earlier blog about firewood alerts on National forests, parks, etc. here).

What You Can Do

Many Californians are pushing for action … they need our help! If you live in California, contact your state legislators. If you live elsewhere, your forests are also at risk from California’s failure to act. So, if you know someone who lives there, ask that person to contact his/her legislators. Ask the legislators to (a) demand state designation of PSHB, KSHB, and GSOB as quarantine pests and adoption of state firewood regulations and (b) support funding for these programs.

The U.S. Congress has a role in convincing APHIS to play a bigger role. Contact your federal Senators and Member of Congress and urge them to ask USDA APHIS to regulate movement of firewood, green waste, and nursery stock from areas infested by the polyphagous or Kuroshio shot hole borers and goldspotted oak borer.

President Trump will soon propose funding levels for government programs, including APHIS’ “tree and wood pest” program. Please keep informed about these proposals – and contact your Congressional representative to express support for adequate funding. Contact me using the “Contact us” button on our website if you wish to receive informative alerts about the upcoming appropriations process.

Posted by Faith Campbell

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

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

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

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

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

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

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

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

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

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

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

What Should We Do?

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

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

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

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

Expect to hear from me often in the coming year!

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

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

Posted by Faith Campbell

The Latest on Phytophthoras

Phytopthora ramorum on tanoak in California; F.T. Campbell

Nine eastern states are participating in the 2016 USDA National Phytophthora ramorum Early Detection Survey of Forests. Those states are AL, FL, GA, MS, NC, PA, SC, TN, and TX. As of late August, streams in four locations were P. ramorum-positive. Three are in AL, one in MS. All had tested positive in previous years. Also, all have been associated with previously positive nurseries. (Reported in the California Oak Mortality Task Force newsletter for September.) It is reassuring that no new positive locations have been detected. However, on what substrate is the pathogen persisting? Scientists agree that the pathogen does not survive in water (although it is reliably detected by testing in water) but must survive on some plant material – perhaps roots.

P. ramorum also persists in nurseries. Seven California nurseries are participating in the APHIS federal P. ramorum program under which they are allowed to ship host plants interstate. Positive plants have been detected in two of them. One of these nurseries is undergoing the Confirmed Nursery Protocol clean-up. The other has completed the cleanup and has been allowed to resume shipping plants interstate. In both cases, the infected plants were not from the five “high-risk” genera which are the focus of monitoring for the regulatory system — Camellia, Kalmia, Pieris, Rhododendron, and Viburnum. (Reported in the California Oak Mortality Task Force newsletter for September.) I expressed concern about this too-narrow focus in a blog posted in July 2015 – http://nivemnic.us/2015/07/.

I have written about the widespread presence of various Phytophthoras in nurseries in blogs in April (for Europe http://nivemnic.us/2016/04/ ) and July (for California http://nivemnic.us/2016/07/ ). New publications add to this picture.

Junker and colleagues (see references below) report the detection of 15 Phytophthora species in two commercial woody ornamental nurseries (presumably in Europe, since the authors are Europeans). Twelve of the species are previously described but the DNA of three isolates did not match any of the known species. Detections were highest in puddles on nursery pathways; followed by plant residues;, wind-carried leaves; and water and sediment from runoff. The plant samples showed very low infection rates – a disturbing finding given the reliance until recently on inspection of plants to detect the pathogen. (Reported in the California Oak Mortality Task Force newsletter for September.)

New Phytophthora confirmed in U.S.

The United States has the first official confirmed detection of the pathogen Phytophthora quercina. It was found associated with oak trees planted on restoration sites in central coastal California. Although the California detection is the first officially confirmed detection of the pathogen in the U.S., a P. quercina ‘like’ organism has been reported to be associated with oak decline in forests in the Midwest. P. quercina is a pathogen associated with oak decline across Europe. It was rated as the species of highest concern in a USDA Plant Epidemiology and Risk Analysis Laboratory (PERAL) report. Another pathogen, P. tentaculata, was rated fifth on the same list. It was recently found in association with multiple native plant species in California’s native plant nurseries (see my July blog, linked above). See also California Oak Mortality Task Force newsletter at http://www.suddenoakdeath.org/news-and-events/current-newsletter/

Rapid Response Might Have Contained SOD – When will authorities learn this lesson?

Earlier this year, experts on modeling the epidemiology of plant disease concluded that the sudden oak death epidemic in California could have been slowed considerably if aggressive management actions – backed by “a very high level of investment” – had started in 2002. By then, there was sufficient knowledge about the disease to guide actions. Management actions should have focused on the leading edge of the epidemic (admittedly, that edge has proven difficult to detect). The study is by American and British scientists (Cunniffe, Cobb, Meentemeyer, Rizzo, and Gilligan). See reference and news report below.

The authors’ estimate documents the high costs of inaction. This is an important lesson – which has been repeated many times. If only officials from California and APHIS would take this to heart regarding several other forest pests. These include the polyphagous and Kuroshio shot hole borers and even the goldspotted oak borer (all described here).

References

Junker, C., Goff, P., Wagner, S., and Werres, S. 2016. Occurrence of Phytophthora in commercial nursery production. Plant Health Progress. 17:64-75.

Posted by Faith Campbell