Center for Invasive Species Prevention

How many new tree-killing pests can we expect?

Several analyses seek to quantify the risk that new tree-killing pests will be introduced to North America. They use different data sources and assumptions, and reach somewhat different conclusions. But all agree that the risk remains high, and the consequences of such introductions are dire.

I have relied on the Aukema et al. 2010 (see references at the end of the blog) and Haack et al. 2014 studies in past blogs. Aukema et al. 2010 looked at the probable dates of introduction for established insects and pathogens to determine that over 150 years, from 1860 to 2006, damaging forest insect and pathogen species were detected at an average rate of between 0.47 and 0.51 species per year. This translates to one damaging insect or pathogen every 2.1 to 2.4 years. The frequency of detection of high-impact forest pests rose sharply after 1990; beginning that year, detections of high-impact forest pests averaged 1.2 per year, nearly three times the rate of detections in the previous 130 years.

In 2013, 25 million shipping containers entered the U.S. An estimate from more than a decade ago is that wood packaging is used in about half of these containers. Haack et al. (2014) has estimated that 0.1% (1/10^th of 1%) of the wood packaging in more than 12 million shipping containers entering the country each year is infested with quarantine pests. That works out to nearly 13,000 containers harboring pests that probably enter the country each year. That is 35 potential pest arrivals per day.

Leung et al. 2014 concluded that continuing to implement the international standard — ISPM#15 — at the efficacy level described by Haack et al. would result in a tripling of the number of non-native wood-boring insects introduced into the U.S. by 2050.

Koch et al. 2011 have also attempted to determine the current rate of introduction of wood-boring insects. They also sought to evaluate the introduction risk for specific metropolitan areas.

Koch et al. utilized various sources of information about volumes of imports of goods likely to be associated with wood-boring pests (e.g., raw wood and wood products; and stone, metals, non-metalic minerals, auto parts, etc., contained in wooden crates and pallets) to estimate both a nationwide establishment rate of wood-boring forest insect species and the likelihood that such insects might establish at more than 3,000 urban areas in the contiguous US.

They estimated the nationwide rate of introduction of wood-boring pests at between 0.6 and 1.89 forest pest species per year for the period 2001–2010. Even the more conservative estimates points to establishment of a new alien forest insect species somewhere in the US every 2–3 years. If one accepts the ‘‘tens rule’’ – that one out of ten new introductions proves to have substantial effects, then one expects establishment of a significant new pest on average every 5 – 6 years. The authors note that the establishment of at least four ecologically and/or economically significant alien forest insects during the past 20–25 years – emerald ash borer, Asian longhorned beetle, Sirex woodwasp, and redbay ambrosia beetle – fits the model’s conclusion. [All of these pests are described in the Gallery of Pests posted here.]

The Aukema et al. estimate for introductions of “high impact” pests during the period after 1990 – 1.2 per year – is in the middle of the Koch et al. estimate for wood-borers, but higher than the Koch et al. estimate for “significant” pests.

Koch et al. estimated a lower rate of introductions between 2010 and 2020 – between 0.36 and 1.7 species per year. The Haack et al. and Leung et al. analyses would seem to contradict this expectation. Also, the findings of Seebens et al. (see my blog from earlier this week) contradicts any expectation that introductions will soon decline as a result of depletion of the pool of possible pests in origin countries.

Koch et al. analyzed data on imports of relevant commodities from all source regions to determine the introduction risk for 3,126 urban areas in the country. The urban area at greatest risk was Los Angeles–Long Beach–Santa Ana, California. The predicted introduction rate for both 2010 and 2020 for this metropolis was establishment of a new alien forest insect species every 4–5 years. The port of New York-Newark came in second, with a predicted establishment rate of one every 8–9 years. Houston ranked third; its predicted establishment rate was one every 13–15 years. All other urban areas were at substantially lower risk – a new introduction every 24 years.

Looking ahead to the decade 2010 to 2020, Koch et al. found that three California metro areas – Los Angeles–Long Beach–Santa Ana; San Diego; and Riverside-San Bernardino – would be exposed to increased establishment rates driven by the growth of imports from Asia.

Risk To Canada

Yemshanof et al. 2011 applied the Koch et al. methodology to evaluate the risk to Canada. Reflecting the lower volume of imports entering Canada compared to the U.S., they found a lower nationwide entry rate for Canada – 0.338 new forest insect species per year vs. the Koch et al. estimate of 1.89 for the U.S. Evaluating individual urban areas, they found the greatest risks to the Greater Toronto and Greater Vancouver areas. Moderate-sized cities near ports, major markets, or U.S.-Canada border crossings – transportation hubs – were also at heightened risks.

Canada as Pest Pathway to U.S.

Yemshanof et al.’s model indicates that 8% of all tree pests entering the U.S. as estimated by Koch et al., come through goods transshipped through Canada. The risk is highest to the Pacific Coast states since they are the most likely to receive Asian goods transiting through Canada. Note that the U.S. and Canada have proposed requiring that wood packaging originating in one of the countries and shipped to the other should be included under the ISPM#15 regulation. However, APHIS was unable to adopt this regulation under the Obama Administration, and such an action seems even less likely under the Trump Administration.

Neither study included plant imports, which are another very important pathway for introduction of tree-killing pests, especially pathogens.

SOURCES

Haack RA, Britton KO, Brockerhoff EG, Cavey JF, Garrett LJ, et al. (2014) Effectiveness of the International Phytosanitary Standard ISPM No. 15 on Reducing Wood Borer Infestation Rates in Wood Packaging Material Entering the United States. PLoS ONE 9(5): e96611. doi:10.1371/journal.pone.0096611

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

Leung, B., M.R. Springborn, J.A. Turner, E.G. Brockerhoff. 2014. Pathway-level risk analysis: the net present value of an invasive species policy in the US. The Ecological Society of America. Frontiers of Ecology.org

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

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.

Alien species introductions — going up!

trade transports many invasive species

Containers at Long Beach, California; courtesy of the Port Authority

In an article published recently in Nature Communications , Hanno Seebens and 44 coauthors show that the rate of new introductions of alien species has risen rapidly since about 1800 – and shows no sign of slowing down. See a summary of the article with revealing graphs here .

Through analysis of a database covering 45,813 first records of 16,926 alien species established in 282 distinct geographic regions, the authors determined that the number of new species reports reached a maximum of 585 in 1996 (or an average of more than 1.5 sightings per day).

Of course, whether a species’ introduction is detected depends on a variety of factors. One of the most important is the species’ impact – or lack thereof! – on economically important resources – this determines whether the species gets noticed. Furthermore, detection usually happens some time after a species’ actual introduction. And, regardless of factors motivating human attention, some types of species are more easily detected than others. All these factors skew the findings. Because many introductions are not detected, Seebens et al. note, their data underestimate actual introductions.

The authors found that the adoption of national and international biosecurity measures during the 20th century have slowed introductions – but they are not yet sufficiently effective. Most notably, numbers of reported new introductions of fish and mammals have decreased since the early 1950s. Of course, introductions of these taxa are usually the result of deliberate decisions, usually by authorities. It is encouraging that authorities appear to be getting the message that adding new species to an ecosystem is a risky enterprise.

Japanese honeysuckle; courtesy of Bugwood.org

However, not all deliberate introductions have been curbed. Seebens et al. were surprised to see that vascular plant species introductions remained at such a high rate throughout the 20^th century. Introductions of birds and reptiles also continue to rise, largely as pets in countries with strengthening economies.

For those plants and animals that are introduced primarily accidentally as stowaways on transport vectors or contaminants of commodities (e.g., algae, insects, crustaceans, molluscs and other invertebrates), Seebens et al. found a strong correlation between their spread and the market value of goods imported into the region of interest.

Having noted that almost all biosecurity efforts are not yet slowing introductions adequately, Seebens et al. point to New Zealand as the exception. That country adopted the Biosecurity Act in 1993 and the Hazardous Substances and New Organisms Act in 1996.

Although 20 years is a short period to gauge a policy’s efficacy – especially given time lags in detecting introductions – Seebens et al. say the stringent new policy appears to be succeeding. They found a significant decline in the number of new alien plants detected in New Zealand since the 1990s. New Zealand’s laws rely on a “white list” of permitted species rather than the more usual “black list” of prohibited species. New Zealand requires a risk assessment before a decision is made to allow any new species to be brought into the country.

Of course, such an approach does not apply easily to the taxa most often introduced as unintended hitchhikers on, or as contaminants of, imported goods, packaging, or transport vehicles – such as tree-killing insects and diseases. The paper notes that existing biosecurity regimes have not slowed down the accumulation of alien species introductions overall, but especially those arriving mainly accidentally, such as invertebrates and pathogens.

As a consequence, Seebens et al. expect that the numbers of new alien species will continue to increase.

I have previously blogged about other studies that show continuing introductions of forest pests and other specific taxonomic groups. See blogs about (1) 2014 IUCN report on invasive species threats to World Heritage sites; (2) IUCN analysis of red-book-listed species – causes of endangerment; (3) rate of new plant pests being detected in US; (4) Jung et al. on Phytophthoras in Europe; (5) Zamir’s critique of international the phytosanitary system; (6) Klapwjik et al. on European efforts to strengthen regulations governing movement of living plants; (7) ISPM#15 11^th anniversary.

Other recent studies have also examined the bioinvasion situation for the whole Earth or major regions. Liebhold et al. 2016 studied insect assemblages in 20 regions around the world. They found that which insect orders are present in a particular region differs completely depending on whether one is looking at native or at nonindigenous assemblages. The authors believe that difference is largely caused by the varying probability that an insect taxon can take advantage of one or more high-volume invasion pathways – such as trade in agricultural products, movement of plants by international travelers, shipments of stored grain, trade in living plants, hitchhiking (e.g. on the outside of shipping containers) and wood packaging. Pathway association appeared to be more important than insects’ life-history traits, which affect their ability to establish in a new ecosystem.

Maartje J. Klapwijk and several colleagues note that growing trade in living plants and wood products has brought a rise in non-native tree pests becoming established in Europe. The number of alien invertebrate species has increased two-fold since 1950; the number of fungal species has increased four-fold since 1900.

Jung et al. (2015) studied the presence of Phytophthora pathogens in nurseries in Europe. They found

Two-thirds of the Phytophthora taxa detected in European nurseries by the present study were unknown to science before 1990.
None of the 59 putatively exotic Phytophthora taxa detected in the present study had been intercepted at European ports of entry.
Spread of the quarantine organism ramorum has not been halted despite the presence of strict quarantine regulations.

I will post a blog examining introduction rates for tree-killing insects and pathogens specifically in the near future. In the meantime, see the published studies listed below as well as my earlier blogs and fact sheets posted here .

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)

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

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

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

Posted by Faith Campbell

Collapse of funding for ALL aspects of EAB management (except biocontrol)

dead ash, Fairfax VA; FT Campbell

In the 25 years or more since it was introduced to North America, the emerald ash borer (EAB) has spread to portions of 27 states. and more widely across Quebec and Ontario. The U.S. quarantine area now covers 682,000 square miles. This has happened despite USDA APHIS spending more than $310 million (U.S.) and Canadian Food Inspection Service spending $25.7 million (Canadian).

The emerald ash borer has been a difficult insect to manage – it is cryptic, developing detection tools and management strategies required years of research and trial-and-error, it is easily transported to new areas in firewood. The beetle’s spread has been discouraging. However, now is not the time to give up! Large areas in which ash trees play significant roles in natural systems and planted areas are still outside the infested area. The tools and strategies can now be more effective in slowing further spread. Yet APHIS is now cutting funding for virtually all program components except biological control.

See the APHIS funding history below.

USDA APHIS Funding History for Emerald Ash Borer, FY 2003-2015
	ALLOCATION
Fiscal Year	appropriation	Emergency funds from Commodity Credit Corporation	Carryover (funds not spent in previous years)	TOTAL
2003	0	$12,442,000	$0	$12,442,000
2004	$1,208,000	$39,879,000	$0	$41,087,000
2005	$4,937,000	$30,140,000	$0	$35,077,000
2006	$10,000,000	$15,000,000	$0	$25,000,000
2007	$6,777,149	$21,185,670	$0	$27,962,819
2008	$22,863,672	$8,884,802	$0	$31,748,474
2009	$34,625,000	$0	$0	$34,625,000
2010	$37,205,000	$0	$0	$37,205,000
2011	37,130,590	$0	$0	$37,130,590
2012	$9,727,000	$0	$15,000,000	$24,727,000
2013	$10,095,570	$0	$0	$10,095,570
2014	$8,999,000	$0	$0	$8,999,000
2015	$7,849,000	$0	$0	$7,849,000

TOTAL	$207,166,000	$103,084,000		$310,200,000

Obviously, funding for the EAB program has fallen significantly. Nevertheless, funding for EAB continues to absorb a significant proportion of funding available for countering the full range of tree-killing pests. APHIS’ total funding for “tree and wood pests” is $54 million. Funding for this program is expected to decrease in the coming years – at the same time as the number of introduced pests continues to rise.

(Other programs funded under the “tree and wood pest” line item are the Asian longhorned beetle – which receives $35-40 million; and European gypsy moth – which receives $5-6 million. [Paul Chaloux, USDA APHIS, pers. comm. February 2017)

APHIS is actively considering ending the EAB regulatory program – which would allow the agency to reduce its costs significantly. (It is unclear whether APHIS would apply the money thus “saved” to other tree-killing pests. I have blogged frequently about pests that APHIS is not addressing.) APHIS would continue to support the biocontrol program.

Ending the regulatory program would probably speed up EAB’s arrival in those western states with significant ash resources. These include the northern Great Plains; the coastal mountains of Washington, Oregon, and California; and riparian areas of Utah and Arizona. For example, North Dakota has 78 million ash trees, which constitute half of trees in riparian woodlands and 60% of planted shelterbreaks.

A map showing areas of Oregon at risk is contained in my blog linked to above. The APHIS website contains a continental map showing areas with significant ash tree populations.

APHIS has already cut funding for EAB provided through the Farm Bill Section 100007 program. In Fiscal Year 2016, EAB programs received $285,000 through this program. Half went to academics for study of oviposition hosts or attractants. This funding dropped to $91,000 in FY17. This year, the funding is almost exclusively to academics studying the effect of EAB density and tree condition on parasitism by one of the biocontrol agents.

APHIS has pledged to continue supporting work on biocontrol programs targetting emerald ash borer.

USFS

The USDA Forest Service is also reducing its engagement on EAB: Forest Health Protection allocated only $240,000 in 2016; Research allocated a little under $1.2 million. USFS funding history is provided in the table below. It can be argued that the USFS has provided the necessary guidance to state, city, and local officials in preparing for EAB decimation of ash trees under their jurisdiction.

However, it is important that USFS Research funding be maintained to support such long-term restoration strategies as resistance breeding.

USFS Funding on Emerald Ash Borer, FY 2009-2016

	FY09	FY10	FY11	FY12	FY13	FY14	FY15	FY16
EAB	$3.9 M	$6.4 M	$6.4M	$4.1 M	$2.8M	$1.8M	$1.7M	1.4M

Important projects are already not being funded; I blogged last year about the loss of funding for Dr. Pierluigi (Enrico) Bonello and others at Ohio State and Wright State University, who are trying to understand how Manchurian ash trees resist EAB attack.

Impact of EAB Deregulation — Whither Firewood Regulation?

If the federal EAB quarantine is eliminated, what will be the impact on federal and state efforts to discourage movement of firewood so as to protect the Nation from this and other pests?

EAB remains a threat to urban, rural, and wildland forests across the continent (including in Mexico) – and EAB continues to be moved in firewood. Furthermore, many other damaging insects and some pathogens can be transported in firewood.

Most of the state firewood regulations require a tie to specific pests – and EAB has been the principal species invoked. Can states maintain their regulations by anchoring them to other pests? Or based on the general threat? I hope so!

Deregulation of EAB seems likely to be the death knell for the APHIS effort to erect a nation-wide industry certification program for firewood. Certification already appears unlikely to be adopted; as I described in my blog in November), the costs of a certification program are higher than retailers are willing to support.

The educational messages recently placed on the Reservation.gov website are likely to remain. These alert campers making reservations at most National parks and many National forests to avoid moving firewood to slow the spread of tree-killing pests. These areas deserve continued protection. A full range of pests put them at risk, many of which are not regulated by APHIS, e.g., hemlock woolly adelgid and walnut twig beetle,

Posted by Faith Campbell

A Tale of Two Pests: APHIS’ Response Contrasts Greatly

spotted lanternfly

Holly Raguza, Pennsylvania Department of Agriculture

I have not written previously about two insects that threaten fruit and forest trees in the U.S. – the spotted lanternfly (Lycorma delicatula) and the velvet longhorned beetle (Trichoferus campestris). APHIS has adopted strangely – and unexplained – different approaches to the two.

Spotted Lanternfly – Pennsylvania Jumps In; APHIS Provides the Funding

The spotted lanternfly (Lycorma delicatula) was first detected in southeast Pennsylvania in autumn 2014. It is native to China, India, and Vietnam. What was known then about its host range came from experience in Korea, where it had also been introduced. Officials were alarmed because the lanternfly is considered a pest of grapes and peaches – both are major crops in Pennsylvania (Spichiger Update; see reference below).

Currently, outbreaks of the spotted lanternfly are in 74 municipalities in six counties in the southeastern part of the Commonwealth – covering a total of 829 square miles. In the more than two years since its detection, the spotted lanternfly has not spread to the rest of the Commonwealth or to other states. Authorities therefore believe that the state’s quarantine is having an impact (Spichiger Update & pers. comm.).

Pennsylvania’s authorities believe the lanternfly utilizes about 80 species of plants, especially during the early stages of its development. A monitoring program managed by Dr. Gregory Setliff of Kutztown University (see reference below) has developed a list of 24 putative hosts – including maples, birches, hickories, dogwoods, beech, ash, walnuts, tulip tree, tupelo, sycamore, poplar, peaches and plums, oaks, willows, sassafras, basswood, and elms. Setliff also found that the lanternfly will penetrate into woodlands; it does not stay on the edges.

Adults strongly prefer the widespread invasive species tree of heaven (Ailanthus altissima). In fact, it might be necessary for adults to feed on Ailanthus before laying their eggs. However, oviposition can occur on not just a wide variety of plants but also nearly any hard surface (Spichiger).

Officials are optimistic that an approach using trap trees will eradicate the spotted lanternfly. They remove most Ailanthus, then apply a systemic pesticide to the remaining trees to kill adult lanternflies when they feed (Spichiger).

Fortunately, this insect is conspicuous. As a result, 90% of citizen reports of sightings have proven to be accurate (Spichiger). This contrasts greatly with phytosanitary officials’ experience with Asian longhorned beetle, emerald ash borer, and other tree-killing pests.

Scientists in both Pennsylvania and China are looking for natural enemies.

The entire program in Pennsylvania has been funded through a series of Farm Bill grants from APHIS (Spechiger pers. comm.). These began in FY2016, right after the 2014 detection. By FY2017, Farm bill funding totaled nearly $2 million; it went to a myriad of entities to: study lanternfly lifecycles and host preferences; find possible biocontrol agents and chemical treatments; and – especially – for outreach and education. Nearly $1.6 million of these funds went to state agencies in Pennsylvania.

Velvet Longhorned Beetle — States Limp Along; APHIS Support Minimal

velvet longhorned beetle

Christopher Pierce, Bugwood

In contrast to the spotted laternfly, populations of the velvet longhorned beetle (VLB Trichoferus campestris) appear to be more long-standing and more widely spread. It was first found in 2010 in Utah. Now, it has been detected 15 separate times in Quebec and 11 U.S. states, according to Wu et al. 2017 and websites listed below. States specifically mentioned by sources include Illinois, Minnesota, New Jersey, New York, Ohio, Pennsylvania, and Rhode Island. Most are of single or a few beetles – although detections are sometimes repeated over several years – e.g., in Minnesota.

In contrast, the outbreak in Utah appears to be established and growing. The number of beetles detected has exploded from 4 in 2010 to 1,863 in 2015 .

Like so many other invaders, this beetle is known to be native to East and Central Asia.

The host range is still being studied. Hosts are thought to include more than 40 genera, including apple; cherry and peach; maple; birch; mulberry and paper mulberry; beech; ash; honey locust; mountain ash; willow; and cut wood of spruce and pine.

Like other woodborers, the velvet longhorned beetle has often been intercepted in wood packaging (see my earlier blogs. There have been 29 interceptions of the Trichferous genus over 3 years. Some of the newly established populations – such as Utah’s outbreak – are tied to specific shipments in which wood packaging was insect-infested (Wu et al. 2017).

VLB has also been detected in imported rustic furniture – probably because the beetle is apparently much more tolerant of tunneling in dry wood than other Cerambycids. In some pieces, insect activity was not detected until 18 months after the furniture was purchased. In 2016 a Minnesota homeowner discovered a beetle emerging from bark-covered furniture that she had purchased more than a year earlier. Furniture from this shipment was shipped to at least 10 other states [Mark Abrahamson, Minnesota Department of Agriculture, pers. comm. February 16, 2017]. The Minnesota Department of Agriculture, APHIS, and other State departments of Agriculture are working with the furniture seller to recover and destroy all infested furniture.

Detection of the velvet longhorned beetle has been hampered by the absence of a good lure for traps. Dr. Ann Ray of Xavier University in Ohio has isolated and identified a possible lure but needs another field season to determine the right amount of pheromone for each trap. While Dr. Ray’s earlier work had been funded by APHIS through its Section 10007 program, APHIS chose not to fund the final stage of testing in the FY2017 Farm Bill grant program. Indeed, no VLB programs were funded this year.

This contrasts sharply with APHIS’ continued engagement with the spotted lanternfly.

The extent of damage to fruit trees caused by the velvet longhorned beetle has been difficult to determine (Ray; see reference below). Perhaps for this reason, APHIS has not adopted an official stance on whether the beetle is “established” in the United States. Thus, five years after the insect was detected for a second year in Utah, the agency cannot make up its mind how great the threat is and what the agency’s response should be.

If the velvet longhorned beetle turns out to be highly damaging, eradicating it will have become increasingly difficult during the years that APHIS has pondered what to do.

SOURCES

Ray, Annie. Evaluation of lure and trap design for monitoring the velvet longhorned beetle Trichoferus campestris. XXVIII USDA Interagnecy Research Forum on Invasive Species January 10 -13, 2017.

Setliff, Gregory P. Investigating the host range of the spotted lanternfly (Lycorma delicatula) in southeastern Pennsylvania. XXVIII USDA Interagnecy Research Forum on Invasive Species January 10 -13, 2017.

Spichiger, Sven-Erik. Pennsylvania Department of Agriculture. Update on spotted lanternfly program in Pennsylvania. XXVIII USDA Interagnecy Research Forum on Invasive Species January 10 -13, 2017.

Wu,Y., N.F. Trepanowski, J.J. Molongoski, P.F. Reagel, S.W. Lingafelter, H. Nadel1, S.W. Myers & A.M. Ray. 2017. Identification of wood-boring beetles (Cerambycidae and Buprestidae) intercepted in trade-associated solid wood packaging material using DNA barcoding and morphology

Posted by Faith Campbell

New Secretary of Interior Pledges to Support Invasive Species Efforts — Let’s Ask USDA Secretary to do the Same!

Interior Secretary nominee Ryan Zinke

During his confirmation hearing Ryan Zinke, nominated to be the new Secretary of Interior, committed to several senators that he would explore ways to better manage invasive species on federal lands – especially in National parks – and to strengthen the National Invasive Species Council (NISC).

Mr. Zinke is currently a Congressional Representative from Montana. Senator Debbie Stabenow (MI) pressed him on invasive species issues during the hearing, focusing on the threat to the Great Lakes of carp and other aquatic species. Also, Senators Al Franken (MN), Joe Manchin (WV), and Mazie K. Hirono (HI) asked about invasive species in written questions submitted to the nominee.

Mr. Zinke answered most questions the same way: He shares the Senator’s concern, especially since Montana has significant invasive species problems. Also, he thinks it is critical that federal land managers be encouraged and empowered to be good neighbors in controlling invasive species in cooperation with adjacent private land owners. … Specifically he wants to explore ways to implement the Early Detection Rapid Response Framework adopted by NISC in 2016.

* Sen. Franken included a single question on bioinvaders among a long list of questions on other topics. He mentioned the emerald ash borer as one example of a damaging invader in Minnesota. Senator Franken asked Mr. Zinke:

1) what steps he would take to enhance invasive species control on public lands

See paragraph above for Mr. Zinke’s answer.

2) whether he would enforce the Lacey Act and explore ways to strengthen it.

Mr. Zinke said he would enforce the law. He is aware that there is broad bipartisan frustration with the lack of an efficient process for listing injurious species under the Act. He would ask the Fish and Wildlife Service to recommend ways to improve its implementation. If legislative changes might be helpful, he would be pleased to have that conversation with the Congress.

* Sen. Manchin’s first question (!) asked how Mr. Zinke might strengthen NISC to help manage invaders across multiple types of land ownership. See Mr. Zinke’s frequent reference to his Montana experience above for his answer.

* Sen. Hirono asked five questions pertaining to invasive species! Her first question concerned steps to protect National parks (especially in Hawaii) from bioinvasion. Here, Mr. Zinke gave his usual response but added: “I am especially concerned that Hawaii’s unique flora and fauna are vulnerable to invasive species. I would not want to see invasive species push any of these unique plants and animals onto the Endangered Species list. Once confirmed, I will ask the National Park Service to present me with options for better protecting our national parks from invasive species.”

Ms. Hirono also asked about strengthening NISC. Mr. Zinke responded as follows: “…, I will explore ways to improve the operations of the National Invasive Species Council, and actively engage with the Secretaries of Commerce and Agriculture to get off to a strong start on this issue. … We also need to create a more effective linkage between the National Invasive Species Council policy operation in Washington, DC, and the on the ground federal land managers across the country who deal with invasive species on a daily basis…”

Also, Sen. Hirono asked for Mr. Zinke to help Hawai`i and other U.S. Pacific islands to counter the spread of invasive species through movement of military equipment. Mr. Zinke said he would work to enhance coordination with the Department of Defense and the Pacific island communities to reduce the risks posed by invasive species. … explore how we may implement the recent framework for early detection and rapid response …

Mr. Zinke also promised to work with Senator Hirono on several issues under Interior jurisdiction that are priorities for Hawai`i, among them invasive species.

What We Should Ask the new President & Congress to Do re: Invasive Species

While there are many opportunities for the Congress to strengthen U.S. invasive species programs (see my blog from December 31 here, the most important activity NOW is the confirmation of Sonny Perdue as Secretary of Agriculture. Contact your Senators and urge them to ask Governor Perdue how he will address invasive species challenges.

USDA Secretary nominee Sonny Perdue

Possible questions:

Q: How serious do you think is the threat to American natural resources from invasive (non-native) insects, pathogens, and plants? Can you suggest steps you would take to strengthen the efforts of the Animal and Plant Health Inspection Service (APHIS) aimed at controlling introduction and spread of such bioinvaders into the United States?

Q: The principal legal authority for preventing introductions of invasive plants and plant pests is the Plant Protection Act. The PPA provides strong authority but its implementation has been hampered by internal USDA decisions. How would you ensure that the Department corrects these problems and actively enforces its regulations aimed at ensuring the health and productivity of America’s plant resources?

In recent years, more than 20 previously undetected plant pests have been detected in the country each year. Hundreds of shipments of goods entering the country each year contain plant pests. What strategies would you promote to reduce the introduction, spread, and impacts of invasive species?

Q: Given the ever-tightening budget allocated to agencies responsible for addressing invasive species threats, what steps would you take to ensure that our country does not suffer waves of new invasions?

If you have a working relationship with your Senators and believe they understand the invasive species issue fairly well, you might want to suggest more detailed questions:

Q: As you know, the Animal and Plant Health Inspection Service (APHIS) is responsible for preventing introduction and spread of plant pests.

In some cases, APHIS has been hesitant to use its authority to penalize importers which routinely receive shipments that violate plant pest (phytosanitary) regulations. [You might cite my blog from last week which illustrates examples pertaining to wood packaging.] Will you instruct APHIS to use its legal authority to impose civil penalties to deter continuing violations?

Trying to prevent pest introductions by increasing the percentage of shipments that are inspected visually will not be effective in many cases. This is true especially with regard to one of the most important pathways by which plant pests are introduced – imports of living plant material such as nursery stock. APHIS began updating its regulations governing plant imports nearly four years ago, but the proposed new regulations have been not been finalized. Will you look into the reasons for delay and take steps to update these regulations to focus on pathway cleanliness rather than continue to rely on ineffective visual inspections?

Q: Urban forests across the country are under threat from a growing number of non-native or introduced insect pests. Examples include the emerald ash borer – now found in 27 states; Asian longhorned beetle – which threatens a large proportion of urban trees across the country; and polyphagous and Kuroshio shot hole borers – killing many trees in southern California.

Urban forests are at particularly high risk of infestation by non-native pests because they are growing near ports and other transportation hubs where such pests are first introduced. Furthermore, each individual tree in an urban setting provides important benefits in the form of shade, moderation of storm water runoff, abatement of air pollutants, enhanced property values, and neighborhood amenities.

Will you fully utilize the authorities under the Plant Protection Act to help ensure the health and productivity of America’s urban forests?
[If you have not already suggested the questions outlined above re: wood packaging and other pathways, you might suggest them in this context.]

The Secretary of Agriculture also oversees the Forest Service. Pertinent questions:

Q: Invasives are as great a threat to eastern forests as wildfires are in the West. Despite the growing damage and ecological destruction we are witnessing the budgets for research on strategies to minimize these bioinvaders’ impacts are actually falling. How will you work to provide solutions to this quandary?

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

Posted by Faith Campbell

Wood Packaging – Again! 11 years after ISPM#15, problems persist …

ALB pupa; Thomas B. Denholm, New Jersey Department of Agriculture; bugwood.org

As I have noted in earlier fact sheets and blogs, wood packaging (crates, pallets, etc.) has been a major pathway for introductions of highly damaging wood-boring pests since at least the early 1990s. (See Figure 2a in Aukema et al. 2010; reference given at end of blog.)

This rise in introductions followed the rapid increase in use of shipping containers – as described in Levinson’s book The Box (reference below). Levinson notes that shipping capacity increase fourfold during the decade of the 1970s, reaching 10 million tons in 1980. (See also my blog from August 2015 here). A second factor was the U.S. opening trade with China in 1979. Since in those years – before establishment of more sophisticated detection tools – a pest was often present for close to a decade before being detected, it is not surprising that detections of woodboring pests began their rise around 1990.

February 2017 marks 11 years since the international standard (ISPM#15) was put into effect by the United States and 17 years after the U.S. and Canada began requiring China to treat its wood packaging. Nevertheless, numerous shipments containing wood packaging that does not comply with the regulations continue to arrive at our borders – and to bring pests.

A study by scientists and economists (Haack et al. 2014; reference below) analyzed detection data from the U.S. and other countries in order to calculate the reduction in pest risk associated with wood packaging following adoption of ISPM#15. They concluded that one tenth of one percent of the wood packaging entering the U.S. after adoption of ISPM#15 still contained a tree-killing pest. This sounds like a small risk. However, the U.S. imported approximately 25 million shipping containers in 2013 – and presumably similar numbers in more recent years. It has been estimated in the past that wood packaging is used in just over half of these containers. Therefore, even if merely 1/10^th of 1% of the wood packaging in these shipments contained a tree-killing pest, 13,000 containers harboring pests probably enter the country each year. That is 35 potential pest arrivals each day.

Interception records compiled by USDA APHIS and the DHS Bureau of Customs and Border Protection clearly show that wood packaging infested with pests continued to arrive in recent years – including in 2016.

Over a period of seven years – Fiscal Years 2010 through 2016 – CBP detected more than 20,700 shipments with wood packaging that did not comply with ISPM#15. While most of the non-compliances represented wood packaging that lacked the required mark showing treatment per ISPM#15, in nearly 5,000 cases the wood packaging actually harbored a pest in a regulated taxonomic group (see Customs presentation at the Continental Dialogue here).

Customs inspectors at 11 ports (listed at end of blog) have been sending intercepted wood packaging containing insect larvae to APHIS for study. APHIS has also sent to me its record of interceptions for the period FYs 2011 – 2016.

The APHIS interception database contained 2,547 records for insect detections. The insects belonged to more than 20 families. Families with the highest numbers of detections were Cerambycids – 25% of total; Curculionidae – 23% (includes Dendroctonus, Ips, Orthotomicus, Scolytinae, Xyleborus, Euwallacea); Scolytidae – 17% (includes true weevils such as elm bark beetles); Buprestids – 11%; and Bostrichidae – 3%. Not all of the insects in these groups pose a threat to North American plant species.

piece of wood packaging with Cerambycid larva; detected in Oregon

The samples sent by CBP to APHIS are limited largely to the families Cerambycidae (the family containing the Asian longhorned beetle) and Buprestidae (the family containing the emerald ash borer). This dataset contains 1,068 insects, obtained over the period April 2012 through August 2016 from 786 separate interceptions of non-compliant wood packaging. The sample is not from a random set of ports – four of the seven entry points are on the Mexican border, and the proportion was even higher in the early years of the study.

The APHIS interception database reports pests detected in wood packaging from dozens of countries. The countries of origin with the highest numbers of shipments detected to have pests present were Mexico, China, Italy, and Costa Rica. These numbers reflect in part import volumes. The U.S. imports huge volumes of goods from both Mexico and China. (Our second largest trade partner is Canada; the U.S. and Canada have exempted wood packaging moving between the two countries from the requirement that it comply with ISPM#15. Neither country inspects wood packaging from the other country at even the low rate of inspection applied to wood packaging coming from Mexico or overseas.)

The CBP-APHIS database includes pests found in wood packaging from 39 countries, including 212 shipments from Europe; 130 shipments from Asia; and 341 shipments from the Americas – almost exclusively Mexico.

APHIS analysts point out that the pests from Mexico might pose a lower risk since some proportion of them are probably species shared between our two countries. (However, several woodborers from Mexico are killing trees in the U.S. – e.g., goldspotted oak borer, walnut twig beetle, and soapberry borer. These species are described briefly here. These insects were probably introduced to vulnerable parts of the U.S. in firewood rather than wood packaging.)

As always (see the briefs here as well as various articles by Haack and Cavey), imports of heavy objects are associated with wood packaging found to be infested with insects: metal and machine parts, tiles, decorative stone. Imports of fruits and vegetables rank high because of the large number of interceptions in wood packaging from Mexico.

Comparing the estimate by Haack et al. 2014 with the CBP data indicates that Customs is detecting about 6% of all pest-infested shipments. I do not believe that increasing the inspection workforce and effort will result in substantial improvement in this rate.

On average, 26% of infested wood pieces detected by CBP were found in wood that had been treated according to ISPM#15 requirements (if we believe the ISPM#15 stamp on the wood). Does this indicate fraud? Or is the problem accidental misapplication of the treatments? Or are the treatments less effective than hoped? APHIS researchers have found that larvae from wood subject to methyl bromide fumigation were more likely to survive to adulthood than those intercepted in wood that had been heat treated. Does this indicate that methyl bromide fumigation is a less effective treatment?

CBP staff reported that only about 30 import shipments (out of nearly 21,000 shipments found to be in violation of ISPM#15 requirements) have received a financial penalty. CBP staff cite two reasons for the low penalty rate:

USDA policy requires that an importer be caught 5 times in a year with non-compliant wood packaging before authorizing a fine; and
APHIS has not designated SWPM as a high-risk commodity

What Can Be Done to Slow or Eliminate this Pathway?

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

Prohibit imports in packaging made from solid wood (boards, 4 x 4s, etc.) from foreign suppliers which have a record of repeated violations over the 11 years ISPM#15 has been in effect (17 years for exporters from Hong Kong & mainland China). Officials should allow continued imports from those same suppliers as long as they are contained in packaging made from other types of materials, including plastic, metals, fiberboards …

Fine an importer for each new shipment found to be out of compliance with ISPM#15 in cases when the foreign supplier of that shipment has a record of repeated violations.

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

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

What You Can Do

Tell your member of Congress and Senators that you are worried that our trees are still being put at risk by insects arriving in wood packaging. Ask them to urge the new Secretary of Agriculture (Sonny Perdue, former governor of Georgia) to take the actions outlined above in order to curtail introductions of additional tree-killing pests.

Talk to your friends and neighbors & civic organizations about the threat to our trees. Ask them to join you in communicating these concerns to their Congressional representatives and Senators.

Write letters to the editors of your local newspaper or TV news station.

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

Ports that have sent specimens to APHIS lab: Seattle, Long Beach, San Diego, Laredo, Hildago, Houston, Miami, Port Everglades, Chicago, Detroit

References

Haack, R. A., K. O. Britton, E. G. Brockerhoff, J. F. Cavey, L. J. Garrett, M. Kimberley, F. Lowenstein, A. Nuding, L. J. Olson, J. Turner, and K. N. Vasilaky. 2014. Effectiveness of the international phytosanitary standard ISPM no. 15 on reducing wood borer infestation rates in wood packaging material entering the United States. Plos One 9:e96611.

Levinson, M. The Box: How the Shipping Container Made the World Smaller and the World Economy Bigger Princeton University Press 2008

Posted by Faith Campbell

Public attitudes about tree-killing pests

The Nature Conservancy (TNC) has carried out telephone surveys of eligible voters to determine their attitudes about trees and forests and threats to them over 11 years – in 2005, 2007, 2008, 2010, and 2016. Leigh Greenwood will present these finding during a webinar on Friday 27 January. Go here to learn more and register for the webinar.

Michigan champion ash before & after being killed by emerald ash borer

While those surveyed consistently ranked economic concerns as more important than environmental ones, still they have been aware of threat from forest insects and diseases.

In 2016, 23% to 26% of respondents said that they considered diseases or insects that kill trees a “very serious” problem. Notably, these concerns were equal to those expressed about fires that destroy property and forests.

Gardening, hiking, and wildlife viewing are popular activities, engaged in by half or more of the respondents. Only 35% of respondents fish; only 15% hunt.

The sources of information on forest health issues that are most trusted by survey respondents have remained steady across regions and years:

park “rangers” rank first, with 89% of respondents ranking them as “believable”;
the state division of forestry ranks second, with 84% of respondents saying it is “believable”;
the USDA Forest Service and scientists are tied for third, with 82% of respondents saying each is “believable”;
also highly trusted (trusted by more than 70% of respondents) were the State Department of Agriculture, a local forester, and conservation organizations.

The public’s level of familiarity with the concept of forest pests nationwide has been between 53% and 59% of respondents since the Conservancy began polling in 2005. Levels of awareness were higher in 2010 than in either 2005 or 2016 –probably because of media attention to the emerald ash borer.

The specific pests asked about in the polls with the highest levels of awareness have remained Dutch elm disease and European gypsy moth – with somewhat over half the respondents saying they have heard of the problem. About a quarter of respondents have heard something about chestnut blight.

Levels of awareness have changed significantly over time for some regions and some pests.

In 2016, 50% of respondents in the “east north central” region HAVE NOT heard of the Asian longhorned beetle. This contrasts with 2010, when only 18% of respondents in the region said they had not heard about ALB. Perhaps this decline in awareness is because the outbreak in Clermont County Ohio is in a semirural area and does not get the media coverage that earlier outbreaks in cities did. Alternatively, because these polls are conducted in a population proportional sample, it may be that urban residents are not aware while rural residents (in the affected area) are indeed aware but are not captured in the sampling methodology.

Similarly, in 2016 more than a third of respondents in New England said they had not heard about the ALB; this lack of awareness is greater than the quarter who said they had not heard about the insect in 2010. Still, the number of people in the region who had “heard quite a bit about it” has held steady at one-third of respondents. In the Northeast more broadly, 48% in 2016 said they had not heard about ALB, compared to 42% in 2010.

Regarding the emerald ash borer, its spread has apparently led to greater awareness in the South. By 2016, 28% of respondents in the South have heard of it — compared to 18% in 2010. Awareness of EAB has remained steady in the East North Central region – at 76% of respondents. In 2005, when three of the five states in the region were polled, awareness was far lower – 57% said they had never heard of it.

Poll results showed that the proportion of respondents nation-wide who were “extremely or very concerned about non-native forest pests and diseases has declined from 54% in 2010 to 40% in 2016. While the poll does not inform us why this change has occurred, one probable explanation is that the emerald ash borer infestation is no longer front page news in most regions.

Levels of concern are highest in major cities and rural areas.

One of the purposes of the Conservancy’s polling is to measure the effectiveness of the organization’s efforts to educate campers and others about the pest risk associated with firewood. (Visit www.dontmovefirewood.org to see the extensive outreach program and how you can become involved.) Consequently, pollsters paid considerable attention to attitudes about using and moving firewood. In 2016, 47% of respondents say they never burn firewood at home; a different 51% say they never burn firewood when travelling away from home.

Of those who burn firewood at home or outdoors, few now admit to moving firewood – especially in the Northeast and Midwest. In those two regions, 70% plus say they never move it. Those who do move firewood say they move it shorter distances (mostly less than 50 miles).

The polls show the impact of outreach efforts nationwide. In the Northeast and Midwest, those who admit to moving firewood several times have dropped by about half. Indeed, the nation-wide proportion of respondents who admit to moving firewood in 2016 is below the proportion in the most affected region in 2007.

Across the country, 37% have heard that they should not move firewood – slightly above the 34% in 2010. Respondents who have heard the firewood message say this information has made them much less likely to move firewood.

However, there are huge regional differences. In the Midwest (reported as two subregions), between 56% and 70% have heard the firewood message. In New England, 49% of respondents have heard the message. In the Mid-Atlantic region, 40% remember having heard a message about not moving firewood. However, in the South and in the Pacific states, only 30% or fewer of respondents remember having seen or heard a message about firewood. In Rocky Mountain states, the proportion falls to 11%!!!. [ insert the graph? Would it be readable?]

The overwhelming majority of respondents say they are willing to buy firewood where they will burn it after hearing information about pest threat. This proportion was 84% in 2016 – although this is below the 90% who responded positively in 2005.

Types of information that respondents say they are most likely to pay attention to:

Brochure at a park 90% say would pay attention
Information from friend or neighbor 88%
Billboard on highway 84%
Radio ad 78%
Email at time of reserving campground 77% (major program effort)
Label on firewood package 77% (but is this information seen too late – e.g., after people have already arrived with wood in tow?)
Ad on TV 75%
Booth at special event or farmers’ market 75% (DMF has had such booths for years)

Lower proportions said they would pay attention to such other outreach methods as an article in a local newspaper, article in utility bill mailing or e-newsletter, advertisement in outdoor outfitter catalog or newspaper … or even website focused on firewood consumers. Responses vary by age groups. Predictably, digital media categories perform more persuasively in the younger demographics.

The preferred message is “buy it where you burn it.” The very similar “buy local, burn local” is also well accepted by the public according to the polling results, but due to its more limited use area (mostly Vermont and Canada at this time) the campaign recommends using Buy It Where You Burn It to be consistent.

CONCLUSIONS:

Use the slogan that the public prefers – when practical; the “local” message might not fit if the state’s or agency’s program requires that the wood be treat or either allows or encourages gathering of downed wood for the fire.
Outreach is working – the public is changing its behavior to move firewood less frequently and for shorter distances.
Use trusted messengers and outlets/places where people are receptive.
Awareness is temporary; it fades over time — so don’t stop putting the message out!!!!

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

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