Center for Invasive Species Prevention

Cacti under Threat – Does No One Care?

Nearly 2 million square miles of ecologically significant and beautiful desert ecosystems straddle the U.S.-Mexico border regions. Cacti are either dominate or are extremely important components of these ecosystems. Two South American insects already present in the United States threaten to kill large numbers of these cacti and transform these desert ecosystems. Iconic species – prickly pears, saguaro, and organ pipe cacti – are at risk.

prickly pear cactus at Factory Butte; photo by S.E. Schlarbaum

Flat-padded prickly pear cacti of the genus Opuntia are threatened by the cactus moth, Cactoblastis cactorum.
In 1989, the cactus moth was found in southern Florida, to which it had spread from the Caribbean islands (Simonson 2005). Since then, it has spread west as far as southern Louisiana. Two small outbreaks on islands off Mexico’s Caribbean coast have been eradicated. If it reaches the arid regions of Texas, it is likely to spread throughout the desert Southwest.
In Florida, the cactus moth has caused considerable harm to six native species of prickly pear, three of which are listed by the state as threatened or endangered. In the American Southwest, at least 80 species of flat-padded prickly pears are at risk (Simonson et al. 2005) and there are more in Mexico, which is the center of endemism for Opuntia.
These cacti support a diversity of pollinators as well as deer, javalina (peccaries), tortoises, and lizards. Prickly pears also shelter packrats –which in turn are fed on by raptors, coyotes, and snakes; nesting birds and plant seedlings. Their roots hold highly erodible soils in place (Simonson 2005).
The U.S. Department of Agriculture began trying to slow the spread of the cactus moth in 2005 – 15 years after it was first detected in Florida (Mengoni Goñalons et al. 2014). However, the program never received an appropriation from Congress so funding was always inadequate. For several years, a patchwork of projects was stitched together: Mexico provided some funding; a volunteer network managed by Mississippi State University monitored lands along the Gulf Coast for the moth; and a laboratory operated by the Florida Department of Agriculture reared moths for research, sterile male releases and biocontrol host specificity testing.
The continuous funding problems led APHIS to abandon its regional program and focus on biocontrol, which is the only viable control measure in the desert Southwest where vulnerable cacti are numerous and grow close together. A newly described wasp, Apanteles opuntiarum (Mengoni Goñalons et al. 2014), is the most promising candidate.
Harrisia cactus mealybug might attack columnar cacti
The 2 million square miles of desert in Southwest United States and Mexico are home to more than 500 columnar cactus species in the Cactoideae (Zimmerman et al. 2010). Some are already endangered; others are totems of the desert, e.g., saguaro, organ pipe, and barrel cacti. The larger ones, particularly, play important ecological roles.
A second South American insect threatens columnar cacti in the Caribbean basin now and in the future could put others at risk in the American Southwest and Mexico: the Harrisia cactus mealybug (Zimmerman et al. 2010).
A mealybug in the genus Hypogeococcus has been killing several of the 13 columnar cactus species in southern Puerto Rico since 2005. Two are endangered species: Harrisia portoricensis and Leptocereus grantianus (USDA ARS). These cacti provide food or shelter for endemic bats, birds, moths and other pollinators (Segarra & Ramirez; USDA ARS). This mealybug is also now killing native cacti on the U.S. Virgin Islands (H. Diaz-Soltero pers. comm. August 2015).
Mealybugs in the same genus in Florida and Hawai`i do not attack cacti (University of Florida fact sheet; Hawai`i Department of Agriculture new pest report). In South America, though, insects in this genus feed on many columnar cacti, including ones in the genera Cereus, Echinopsis, Harrisia, Cleistocactus, Monvilea, and Parodia (USDA ARS; Zimmerman et al. 2010). Scientists are uncertain how many mealybug species are involved, which complicates efforts to determine the level of threat to columnar cacti on the U.S. mainland (H. Diaz-Soltero pers. com. August 2015). No one knows how vulnerable individual cactus species growing in the Southwest are to Hypogeococcus mealybugs (Golubov pers. comm. January 2011). Nor does anyone know whether natural enemies of mealybugs native to Mexico might also attack alien mealybugs and so prevent significant damage to native cacti (Zimmerman et al. 2010).
Still, the possible threat warrants studies to determine the vulnerability of these cacti to non-native mealybugs in the Hypogeococcus genus.
Meanwhile, scientists at the USDA ARS laboratory in Argentina have been searching for possible biocontrol agents but are stymied by the confusion over which mealybugs attach which cacti. Use of DNA sequencing and other tools should clarify these issues (H. Diaz-Soltero pers. comm. August 2015). However, no funds have been appropriated for this work, which has hindered progress (H. Diaz-Soltero pers. comm. August 2015).
To date, no organized constituency has advocated for protection of our cacti from these two pests. In the past I tried to persuade native plant societies, Nature Conservancy chapters, the leadership of the American Cactus and Succulent Society, and other groups that champion the desert to help lobby the Congress to fund USDA’s efforts. I was never successful.
Are Americans truly indifferent to the threat that many cacti in our deserts will be killed by non-native insects? Do they not realize that these threats must be countered before they reach the areas where cacti are dense and numerous?

Sources
California Plant Pest and Disease Report. 2005. Vol. 22 No. 1. Covering Period from July 2002 through July 2005.
Hawaii Department of Agriculture. 2006. http://hawaii.gov/hdoa/pi/ppc/2006-annual-report/new-pest-detections (accessed 11/1/10)
Mengoni Goñalons, C., L. Varone, G. Logarzo, M. Guala, M. Rodriguero, S.D. Hight, and J.E. Carpenter. 2014. Geographical range & lab studies on Apanteles opuntiarum (hymenoptera: braconiDae) in AR, a candidate for BC of Cactoblastis cactorum (Lepidoptera: Pyralidae) in North America. Florida Entomologist 97(4) December 2014
Segarra-Carmona, A.E., A. Ramirez-Lluch. No date. Hypogeococcus pungens (Hemiptera: Pseudococcidae): A new threat to biodiversity in fragile dry tropical forests. {title/org/other identifying information for Segarra-Carmona plus an entry for the pers. comm.}
Simonson, S.E., T. J. Stohlgren, L. Tyler, W. Gregg, R. Muir, and L. Garrett. 2005. Preliminary assessment of the potential impacts and risks of the invasive cactus moth, Cactoblastis cactorum Berg, in the U.S. and Mexico. Final Report to the International Atomic Energy Agency, April 25, 2005 © IAEA 2005
USDA Agriculture Research Service, Research Project: Biological Control of the Harrisia Cactus Mealybug, Hypogeococcus pungens (Hemiptera:pseudococcidae) in Puerto Rico Project Number: 0211-22000-006-10 Project Type: Reimbursable
Zimmermann, H.G., M.P.S. Cuen, M.C. Mandujano, and J. Golubov. 2010. The South American mealybug that threatens North American cacti. Cactus and Succulent Journal. 2010 Volume 82 Number 3

Posted by Faith Campbell

Hawaii’s unique forests now threatened by insects and pathogens – APHIS & State should act

We have known since Darwin that oceanic islands can be cradles of speciation & endemism. Hawai`i exemplifies the phenomenon. Ninety-eight percent of native flowering plants are endemic (Cox). The density of native insect species in Hawai`i is higher than on mainland North America (Yamanaka).

We have known since Elton or earlier that oceanic islands are highly vulnerable to bioinvasion because their unique species did not evolve defenses against predation, herbivory, competition, or diseases; or the ability to adapt to changed soil chemistry or increased fire frequency.

Chapter 8 of the Office of Technology Assessment study of harmful invasive species states:

“Hawaii has a unique indigenous biota, the result of its remote location, topography, and climate. Many of its species, however, are already lost, and at least one-half of the wild species in Hawaii today are non-indigenous. New species have played a significant role in the extinction of indigenous species in the past and continue to do so. Hawaii, the Nation, and the world would lose something valuable as the indigenous fauna and flora decline.”

I apologize for not addressing the disasters wreaked on Hawai’i’s fauna and non-arboreal flora by invasive mammals and birds, plants, and such animal diseases as avian malaria and avian pox. For more on these topics, see the other sources listed below and the websites maintained by the Hawai`i Invasive Species Council and Coordinating Group on Alien Pest Species. Cox notes that alien species span all trophic groups and threaten the complete replacement of the native terrestrial biota.

Outside of land clearing for ranches and other uses, much of the damage to Hawaii’s native forest trees has been caused by introduced mammals – especially pigs and goats; and invasive plants. Few of the enormous number of non-native insects that have established in Hawai`i appear to have attacked native trees. More than 2,600 non-native insects have been introduced; their number equals three-quarters of the NIS insects established in North America, yet Hawai`i constitutes less than 0.01% of the area of North America. The ratio of non-native to native insect species is higher for Hawai`i than for the other geographic areas studied by Yamanaka and colleagues (mainland North America, “mainland” Japan, and two offshore Japanese islands) (Yamanaka).

More than 13% of the non-native insects (=~350) in Hawai`i were introduced intentionally for biological control of agricultural pests and non-native plants (Yamanaka). Cox, Elton, and the Office of Technology Assessment discuss briefly the sometimes damaging effects of these deliberate introductions.

I am aware of only one NIS insect that has seriously threatened a native tree species: the Erythrina gall wasp, which killed many native wiliwili trees as well as lots of introduced coral trees planted in towns and as windbreaks. Biocontrol agents have helped prevent continuing damage from the gall wasp.

Disease pathogens have so far proved greater threats to Hawaiian native trees than introduced insects. Koa wilt is killing koa, especially at lower elevations. It is not certain whether the pathogenic Fusarium fungus is introduced or native; it has been found on all four major islands. Koa is second only to `ohi`a (see below) in abundance in mid to upper elevation Hawaiian forests. It is extremely important ecologically and culturally (koa was the tree from which large, ocean-going canoes were made). Koa also has a wood valued for a range of uses.

`Ohi`a lehua is the most widespread tree on the Islands, dominating approximately 80% of Hawai`i’s remaining native forest (about 965,000 acres, 1500 square miles). These forests are home to Hawai`i’s one native mammal (Hawaiian hoary bat) and 30 species of forest birds (Loope and LaRosa). One threat to `ohi`a comes from `ohi`a or eucalyptus rust. Detected in April 2005, it had spread to all the major islands by August. Fortunately, the strain of `ohi`a rust established in Hawai`i is not very virulent on `ohi`a, but it has killed many plants of an endangered native shrub, Eugenia koolauensis and in Australia it has killed many plants in the Myrtaceae family. Hawaiian conservationists worry that a different, more virulent, strain might be introduced on plants or cut foliage shipped to the Islands from either foreign sources or the U.S. mainland.

A new, apparently more damaging, pathogen was detected in 2010. This new disease is caused by two newly discovered species of the fungal genus Ceratocystis — Ceratocystis lukuohia and C. huliohia. By October 2015 the disease has killed 50% of the `ohi`a trees in several scattered locations totaling 6,000 acres on the southeast lowlands of Hawai`i (the “Big Island”). Tree mortality was nearing the boundary of Hawaii Volcanoes National Park. Hawaii Volcanoes pioneered methods for controlling invasive pigs and plants that threatened to destroy the Park’s forests. Through 40 years of sustained effort, Hawaii Volcanoes has brought those threats under control. Now the Park faces loss of its invaluable `ohi`a forest to this pathogen – which will be infinitely harder to keep out of the Park. (For updates on “rapid ohia death” visit the write-up here.)

The Hawai`i Department of Agriculture has adopted an emergency regulation aimed at preventing transport of infected wood or tree parts from the Big Island to other islands.

Although tree-killing insects and pathogens have so far not been as damaging in Hawai`i as might be expected, the Islands are highly vulnerable due to the large volumes of cargo and people from around the globe which land on the Islands and the few tree species native there. The Erythrina gall wasp has island-hopped from the east coast of Africa to Hawai`i and many islands in between. `Ohi`a rust is native to tropical America and probably reached the islands on cut stems used in floral decorations. It is unknown where the Ceratocytis fimbriata strain evolved or how it reached Hawai`i.

USDA APHIS is responsible for preventing introduction of new plant pests to Hawai`i from non-U.S. jurisdictions (as well as from Guam). APHIS has traditionally paid little attention to plant pests that are thought likely to threaten “only” Hawai`i but not plant (agricultural) resources on the mainland.

Hawaiian authorities are responsible for preventing introductions from the Mainland – but they struggle with inadequate resources to address the huge volumes of incoming freight and they sometimes hesitate to act. (Hawai`i Department of Agriculture considered restricting shipments of foliage in the Myrtacea to minimize the risk of introduction of a new strain of `ohi`a rust, but in the end did not adopt such a measure.)

Hawai`i’s unique biota is an irreplaceable treasure. All Americans should act to prevent introduction additional introductions to the Islands.

SOURCES:
Cox, George W. Alien Species in North America and Hawaii Impacts on Natural Ecosystems 1999
Elton, Charles S. The Ecology of Invasions by Animals and Plants 1958; see especially Chapter 4: The Fate of Remote Islands
Loope, L. and LaRosa, A.M. `Ohi`a Rust (Eucalyptus Rust) (Puccinia psidii Winter) Risk Assessment for Hawai`i
U.S. Congress Office of Technology Assessment. 1993. Harmful Non-Indigenous Species In the United States. OTA-F-565; available at http://govinfo.library.unt.edu/ota/Ota_1/DATA/1993/9325.PDF

Yamanaka, T., N. Morimoto, G.M. Nishida, K. Kiritani, S. Moriya, A.M. Liebhold. 2015. Comparison of insect invasions in North America, Japan and their Islands. Biol Invasions DOI 10.1007/s10530-015-0935-y

Posted by Faith Campbell

Californians – regulate firewood! Protect your trees!

A new outbreak of the goldspotted oak borer raises again the question of why California does not outlaw the movement of untreated firewood.

goldspotted oak borer

This beetle – which has already killed more than 80,000 oak trees! – has been detected in the town of Green Valley, a small town in Los Angeles County north of the city, and inside the boundaries of the Los Padres National Forest. The first surveys found 27 coast live oak trees with symptoms of beetle attack.
The beetles in Green Valley are genetically identical to those in San Diego County – strongly indicating that the outbreak was started by people moving firewood out of the infested area.
As I noted in my blog dated July 15, the California Department of Food and Agriculture (CDFA) has so far refused to adopt regulations governing movement of firewood. While CDFA and other entities have sponsored billboards, flyers, and other outreach materials to educate people about the risk associated with firewood, the failure to ban firewood movement puts oaks throughout the state at risk.

areas of California in which oaks are at risk to GSOB (redder areas at greatest risk)

A second pest – the polyphagous shot hole borer and its associated Fusarium fungi – threatens a much wider range of trees. It is currently established in Los Angeles, Orange, San Bernardino, Riverside, and San Diego counties. It is known to attack Coast live oak, valley oak, Engelmann oak, California sycamore, big leaf maple and box elder, cottonwood, alder, and ash. This beetle, too, can be moved in firewood.
Californians should ask Governor Brown to adopt regulations restricting movement of untreated firewood. Act now! to protect your trees from goldspotted oak borer, polyphagous shot hole borer, and other non-native insects.
Posted by Faith Campbell

APHIS has a tough job – and deserves praise

Carrying out a pest eradication program is a tough job – technically difficult, expensive, frustrating, and often generating opposition from various groups. But often eradication is crucial. It is the essential backup to the strategies aimed at preventing introduction in the first place.

Damage to red maple; photo by Michael Smith, USDA

USDA APHIS is responsible for developing and implementing eradication programs targeting non-native plant pests – including those that kill trees. APHIS just released an environmental impact statement covering its efforts to eradicate the Asian longhorned beetle (ALB) it is available here. The EIS justifies both the eradication program targeting this species, itself, as well as the specific measures used.
The ALB is one of the most damaging pests ever introduced to North America; it would kill trees in 12 genera which collectively grow in forests across the 48 continental states. In the Northeast (a 20-state area reaching from Minnesota south to Missouri and east to Maine and Virginia), trees vulnerable to ALB dominate two forest types that collectively make up 45% of all forests. Indeed, these vulnerable forests cover almost 20% of the entire land area of these states. For a longer description of the ALB threat, read about the pest in the Gallery of Pests and consider the map below.

Areas at risk to ALB; USGS. 2014. Digital representations of tree species range maps from “Atlas of United States Trees” by Elbert L. Little Jr. (and other publications). — Areas at risk to ALB;
USGS. 2014. Digital representations of tree species range maps from “Atlas of United States Trees” by Elbert L. Little Jr. (and other publications).

The APHIS program – carried out with the help of the USDA Forest Service, other federal agencies, state agencies, local governments, and citizen volunteers – has succeed in eradicating ALB from six sites.
The EIS also makes clear what a tremendous effort such an eradication program demands. APHIS began trying to eradicate ALB 19 years ago, upon discovery of the outbreak in Brooklyn. Since then, APHIS has spent $500 million tackling outbreaks in five states, cut down more than 124,000 trees, and treated tens of thousands of additional trees with the systemic insecticide imidacloprid. Yet more work remains because large outbreaks in Worcester, Massachusetts and Clermont County, Ohio are not yet contained. Eradicating these outbreaks will take many years.
The EIS does not explicitly acknowledge the strong opposition that APHIS has faced from people who were understandably anguished over loss of their trees – especially the trees that were still healthy but posed a risk of enabling ALB to persist and spread across the Continent. Some of the opponents were further angered because they believed – based on misunderstandings or false information – that removing those trees was not a necessary action to protect trees across the Continent.
APHIS deserves our gratitude for persisting in its eradication efforts, despite vocal opposition, uncertainty over funding levels, and the many discouraging setbacks encountered while the agency was trying to improve methods to detect ALB and to contain pest populations.
I’m discouraged that the people who owe the most to APHIS don’t recognize the agency’s efforts. Unfortunately, many appear either to take these actions for granted or to ignore them completely. APHIS received only 27 comments on its notice that it would develop the EIS, and only 14 comments on the EIS itself.
Who should have commented? Everyone who cares about:
• The health of hardwood forests composed of maples, elms, ash, poplars, buckeyes, birch, or willows; these genera are most dense in forests of the Northeast, but – as the map above shows – they grow in forested areas throughout the “lower 48”.
• The health of urban forests and the ecosystem and public health benefits they provide. Cities with high proportions of trees vulnerable to ALB range from Seattle to Boston.
• Clean drinking water for. In the Northeast, 48% of the water supply originates on forestlands – and 45% of those forest lands are composed primarily of species that are vulnerable to ALB.
• The economy and jobs in the Northeast. Vulnerable hardwoods produce timber and maple syrup and are the foundation of the “leaf peeper” tourism industry.
Those who actually did provide comments included:
• Six state departments of Agriculture and their national association, the National Plant Board;
• Four officials in other state agencies (primarily forestry or environmental quality);
• Four officials from other federal agencies (three from National Park Service, one from Fish and Wildlife Service);
• About 20 representing the public, of which:
o Four were affiliated with the maple syrup industry;
o Six organizations focused on wildland or rural forests.

I hope that the next time APHIS seeks public input on its programs, the following organizations will provide thoughtful input:
• the national or regional representatives of state forestry departments;
• the many environmental organizations that engage so actively on other types of forest management issues;
• the organizations that advocate for planting and protecting urban forests;
• the groups that support recreation in forests and on associated lakes and streams;
• the organizations that advocate for protection of wildlife habitat.
APHIS tried hard to inform all who might be interested. APHIS posted the scoping notice and availability of the draft environmental impact statement in the Federal Register. Also, it posted alerts on its Stakeholder Registry (which contains almost 12,000 contacts); its e-newsletter; its Facebook and Twitter accounts; and the agency’s “news and information” and ALB-related web pages. In addition, APHIS notified ALB project managers in New York, Massachusetts, and Ohio and their state counterparts and asked that they notify their key contacts; tribal contacts; USDA Forest Service and U.S. Fish and Wildlife Service contacts; plus several specific partners and organizations. APHIS also issued a press release which it shared with federal and state partners.
Why does it matter that APHIS received so few comments? This silence gives political and agency leaders the impression that the American public does not support efforts to prevent the spread or to eradicate tree-killing insects and pathogens. I hope this is not true!
This negative impression remains even if there are many stakeholders who are pleased with the program’s direction and progress. Their choice not to voice their support meant that only those who object to at least some components of the program are heard in the policy arena.
I plead with you – get involved! Support those parts of APHIS’s eradication and containment programs that you think are wise. Criticize those components that you think should be strengthened or changed.
Posted by Faith Campbell

Wood Packaging – Customs Efforts & Recent Detections

As noted in my blog of July 15, damaging pests continue to enter the country in wood packaging. The most comprehensive study indicates that tree-killing pests are found in an estimated 13,000 containers entering the country each year – or 35 per day.
These pests are present despite requirements adopted 9 or more years ago that wood packaging be treated.

Types of cargo packaged in wood are inspected by agricultural specialists within the Bureau of Customs and Border Protection , a division of the Department of Homeland Security. CBP agricultural specialists work at 167 sea, air and land ports of entry. See an article about CBP efforts to curb introductions of tree-killing pests posted at http://www.cbp.gov/frontline/2014/12/frontline-december-forest-prime-evil.

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

According to the CBP in the above article, the types of commodities imported that have the highest rates of SWPM-related pest interceptions are metal and stone products (including tile), machinery (such as automobile parts and farm equipment), electronics, bulk food shipments and finished wood articles.
These imports have a long-standing record of pest presence – as described in Chapter 4 of my lengthy report on tree-killing pests.

According to the CBP , 48% of the wood packaging entering the country that does not comply with the treatment requirements comes from Mexico. Mexican maquiladoras are factories that import material and equipment duty-free, then assemble a wide range of products – auto parts, apparel, electronics, furniture, and appliances. Mexico’s 3,000 maquiladoras account for half of Mexico’s exports.
China has the second worst record.
Of course, we import lots of stuff from both countries! However, the China situation is particularly disturbing because the U.S. has required that wood packaging from China be treated since the beginning of 1999 – 16 years!
The ports receiving highest numbers of shipments with non-compliant wood packaging materials have consistently been those along the U.S.-Mexico border, especially in Texas: Laredo, Pharr, more recently Brownsville & Houston. Other ports receiving high volumes of non-compliant wood packaging include Blaine, Washington; Long Beach, California; and Romulus, Michigan.

USDA APHIS and CBP have cooperated in a program under which insect larvae found in wood packaging are identified as to species. In recent years, they have studied larvae detected in wood packaging from eight ports – Long Beach, Seattle; 2 ports in Florida; and three cities on the Texas-Mexico border. (Remember, there are 167 ports of entry across the country, so this sample represented 5% of all ports.) Found at these ports were an unreported total of insects, including 116 individuals in the same family as Asian longhorned beetle (Cerambycids). Forty-three were from China (including 5 ALB), 20 from Russia, and seven from Mexico (Philip Berger, APHIS, at the annual meeting of the Continental Dialogue on Non-Native Forest Insects and Diseases, November 2014)

Most familiar – and frightening! – examples of pests introduced via wood packaging include Asian longhorned beetle, emerald ash borer, redbay ambrosia beetle and its accompanying fungus, and possibly polyphagous shot hole borer and its accompanying fungus – all described here.

The prospect of receiving additional insects from Asia scares everyone. What if a new pest is as bad as the four we already have? The emerald ash borer has already caused the removal of an estimated 50 million trees and continues to spread to ash trees – and now white fringe trees – throughout America east of the Great Plains. Laurel wilt disease (transmitted by the redbay ambrosia beetle) is rapidly eradicating redbay trees in the southeast, including in Everglades National Park – one of the icons of the American conservation movement. The Asian longhorned beetle has already caused removal of more than 124,000 trees from our cities, suburbs, and nearby woodlands – at a cost to federal taxpayers of more than $500 million. If it escapes eradication programs, it threatens trees in 10% of America’s forests. The polyphagous shot hole borer threatens numerous tree species that, collectively, make up more than half the trees planted in urbanareas in Southern California.

While no one denies the threat from insects native to Asia, we should not be complacent about insects from Mexico. Although we are neighbors, our forests are separated by deserts – allowing insects to evolve there to which our trees are vulnerable. Three wood-boring beetles native to Mexico and possibly some U.S. border states are already causing havoc to U.S. trees – goldspotted oak borer, soapberry borer, and walnut twig beetle and its accompanying fungus (all described here). The first two were introduced to vulnerable forests through movement of firewood, not wood packaging. The third – the walnut twig beetle – might be native to California, although thousand cankers disease is killing native California walnuts throughout the state so something is different than it used to be.

goldspotted oak borer

When Customs officials detect wood packaging that does not comply with ISPM #15 (“noncompliance” means one of three things: the wood does not bear the ISPM #15 stamp; or the stamp appears to be fraudulent; or signs of pests are detected), that wood must be re-exported immediately, usually with the associated commodity. If any insects present pose an immediate risk of introduction, e.g., if adults are emerging, the shipment might need to be fumigated before re-export.
Re-exported shipments – and any treatments – cause importers to lose income and face costly delays. Still, the continuing presence of non-compliant wood packaging indicates that these inconveniences are insufficient to prompt importers to take all precautions possible to ensure that packaging used by their suppliers and brokers comply with the requirements.

Why don’t importers use alternative packaging made from plastic, steel, or composites that would not harbor tree-killing insects? Plastic pallets also weigh much less than wooden ones, so transport costs are reduced. Customs has pointed out the advantages. … Still, packaging material made from wood is comparatively plentiful, cheap, easy to repair, biodegradable. So it continues to dominate the market.
What steps can be taken by the U.S. government and importers to minimize the presence of insects in packaging?
• U.S. policy allows an importer to be caught 5 times in 1 year with wood packaging that does not comply with the regulatory requirements. Requirements adopted a decade or more ago should be enforced strictly! The Bureau of Customs and Border Protection and USDA APHIS should instead penalize all importers whose wood packaging does not comply with the regulations.
• The Bureau of Customs and Border Protection should incorporate the wood packaging requirements into its “Customs-Trade Partnership Against Terrorism” (C-TPAT) program .
• USDA APHIS should re-examine the economic pros and cons of requiring importers to switch to packaging made from materials other than wooden boards. The new review should incorporate the high economic and ecological costs imposed by insects introduced via the wood packaging pathway.
• The President’s Office of Management and Budget should allow APHIS to finalize regulations – proposed in 5 years ago! – that would apply the same treatment requirements to wood packaging used in trade between the US and Canada. (Canada has been ready to adopt this measure for several years.)
• Importer’ contracts with suppliers routinely specify penalties for delivery delays; the contracts should be amended to add penalties for noncompliant wood packaging.
• A decade ago, USDA APHIS funded research which developed an ingenious method for detecting mobile pests inside a container. It was an LED light attached to a sticky trap. Placed inside a container, the light attracted snails, insects and possibly other living organisms. The whole mechanism was attached to a mailing container that could be pre-addressed for sending to a lab that could identify the pests. Why was this tool never implemented?

Posted by Faith Campbell

Wood-borers in Wood Packaging: How Did We Get to This Crisis?

shipping container being unloaded at Long Beach

The rising numbers of tree-killing wood-boring insects introduced to the U.S. (see blogs from July 15 and August 3 & fact sheet and sources linked there) are a result of ballooning of trade volumes and use of wood packaging.

This irruption of trade was made possible by adoption of the shipping container to transport a wide range of goods.Moving from place to place are not just finished products but also components that originated in one country and that are to be assembled in another country.

How the shipping container revolutionized trade and manufacturing is detailed by Marc Levinson in his book, The Box: How the Shipping Container Made the World Smaller and the World Economy Bigger (Princeton University Press 2008). The transformation affected not only trade between countries, but also within countries, with some regional economies growing while others faltered.

Dr. Levinson recognizes that he has not addressed environmental damage caused by massive movement of cargo. While Dr. Levinson does not explain which damage he is thinking about, I doubt that he includes introductions of non-native wood-boring pests.

(I don’t know enough about the ballast water pathway to understand the impact of containerized shipping on introductions of aquatic invaders, but it seems likely to be an important factor through three factors: directing trade to new port areas; the ships’ huge size; and taking on of ballast water for those segments of a voyage carrying fewer filled cargo containers. On the other hand, Dr. Levinson says that a balance of cargo moving both ways on a trade route is an important factor in determining which ports thrive.)

Before containers, port costs represented the highest proportion of transport costs. Those costs are no longer an important consideration in determining manufacturing and transport choices. Nor is distance as important as before. What is most important are ports that can move large volumes of goods efficiently. The manufacturer or retailer at the top of the chain finds the most economical place for each step in the manufacturing and assembly process without regard to its location.

The containerization revolution was rapid. Containers were first used in international trade in 1966; within three years, nearly one-third of Japanese exports to the U.S. were containerized, half of those to Australia. In the decade after containers were first used in international trade, the volume of international trade in manufactured goods grew more than twice as fast as the volume of global manufacturing production, 2.5 times as fast as global economic output. Large numbers of specialized container ships were built, at ever-increasing sizes. The largest container ship in 1969 could carry 1,210 20-ft containers. By the early 2000s, ships being built to carry 10,000 20-foot containers; or 5,000 40-foot containers.

When Dr. Levinson wrote his book in 2005, the equivalent of 300 million 20-foot containers were crossing the world’s oceans each year.

The container revolution interacted with “just-in-time” manufacturing, which required rapid and reliable transport. Large companies signed written contracts with suppliers and shippers which included penalties for delays.

In the U.S., Long Beach quickly became the principal port because it (as well as Oakland and Seattle) had excellent rail connections to the interior. By 1987, one-third of containers from Asia destined for the East Coast landed at Long Beach and crossed the U.S. by rail. Perhaps counter to our expectation, only one-third of containers entering southern California in 1998 contained consumer goods. Most of the rest contained intermediate or partially processed goods as part of the new international supply and manufacturing chain.

Containers at Long Beach

On the East coast, Charleston SC and Savannah similarly grew because of transport connections – this time, primarily highways.

So, global trade is huge and growing; and the shipping container moves immense quantities of goods from one ecosystem to another and provide shelter for a vast range of hitchhiking living organisms (in addition to insects in the wood, there can be other insects’ eggs attached to the sides of the container, snails, weed seeds, even vertebrates – a raccoon once staggered out of a shipping container that had crossed the Atlantic from the U.S. to France!).

We need to imagine, test, and apply a variety of tools to suppress the numbers of living organisms traveling in shipping containers.

For example,
• if importer-supplier contracts specify penalties for delivery delays, we should ask why don’t importers amend the contracts to add penalties for non-compliant wood packaging?
• Might the Bureau of Customs and Border Protection incorporate the wood packaging requirements into its “Customs-Trade Partnership Against Terrorism” (C-TPAT) program.
• A decade ago, USDA APHIS funded research which developed an ingenious method for detecting mobile pests inside a container. It was an LED light attached to a sticky trap. Placed inside a container, the light attracted snails, insects and possibly other living organisms. The whole mechanism was attached to a mailing container that could be pre-addressed for sending to a lab that could identify the pests. Why was this tool never implemented?

We can’t stop the trade, but we can be much more aggressive in adopting measures to minimize pest introductions.

Posted by Faith Campbell

Non-Native Pest Threat to Forests of the West Coast

As we Americans import more stuff, the risk of new pest introductions rises, too. Many tree-killing insects arrive as larvae living in crates, pallets, and other forms of wood packaging. While the USDA requires that incoming wood packaging be treated to prevent pests, this regulation has not prevented pests from entering the country on wood packaging.

piece of wood packaging with Cerambycid larva; detected in Oregon

A study has found that perhaps 35 shipping containers harboring tree-killing pests reach our ports each day (Haack et al. 2014). At this rate, in just 35 years, America might suffer invasion by more than 100 new wood-boring species. This would result in a tripling of borers introduced to U.S. (Leung et al. 2014).

Already, wood-boring beetles have been among the most damaging tree-killing pests introduced to the U.S. Our environment certainly doesn’t need invasions by three times as many new wood-borers!

West-coast ports receive lots of incoming shipping containers. Long Beach alone receives about half of the nearly 25 million shipping containers arriving at the U.S. each year. So it is alarming that high-risk insects, including the Asian longhorned beetle (ALB), continue to be found in wood packaging (Berger 2014).

Imported goods that are heavy are more likely to be packaged in wood and that thus pose the greatest pest risk. The highest risk commodities are
• machinery (including electronics) and metals;
• tile and decorative stone (such as marble or granite counter tops) (Harriger 2014).
The west coast ports of Seattle, Los Angeles/Long Beach, and San Francisco all rank in the top 15 out of 3,500 (1/2 of 1%) cities nation-wide for imports of tile and decorative stone, machinery and metals (Colunga-Garcia et al. 2009).

Not only do west coast cities import high volumes of risky goods; a significant proportion of the trees growing in those cities are vulnerable to these pests. Seattle’s three to four million trees belong to more than 300 species – although a mere seven genera constitute two-thirds of the trees (Ciecko et al. 2012). It has been estimated that just four non-native pests (ALB, gypsy moth, emerald ash borer, and “Dutch” elm disease) could cause $3.5 billion in damages. The ALB alone threatens 39.5% of all trees lining the city’s streets (City of Seattle 2013).

San Francisco has an estimated 669,000 trees; 12% are at risk to the ALB (Nowak et al. 2007). Apparently no one has yet estimated the numbers of trees at risk to sudden oak death (SOD), goldspotted oak borer (GSOB), or polypagous shot hole borer (PSHB).

It is essential that USDA APHIS act more aggressively to prevent additional introductions of pests via wood packaging. (For a longer discussion of the wood packaging pathway, visit my previous blog posted on July 15th). In brief:
• APHIS & the Bureau of Customs and Border protection should penalize all importers whose wood packaging does not comply with decade-old regulatory requirements.
• The Bureau of Customs and Border Protection should incorporate the wood packaging requirements into its “Customs-Trade Partnership Against Terrorism” (C-TPAT) program
• APHIS should re-consider the advantages of requiring importers to switch to packaging made from materials other than wooden boards.
• The President’s Office of Management and Budget should allow APHIS to finalize regulations – proposed in 5 years ago! – that would apply the international standard’s treatment requirements to wood packaging used in trade between the US and Canada. (Canada has been ready to adopt this measure for several years.)

SOURCES
Berger, P. Executive Director, PPQ Science and Technology, Presentation to the Continental Dialogue on Non-Native Forest Insects and Diseases, November 3, 2014

Ciecko, L., K. Tenneson, J. Dilley, K. Wolf. 2012. Seattle’s Forest Ecosystem Values: Analysis of the Structure, Function, and Economic Benefits; August 2012; GREEN CITIES RESEARCH ALLIANCE; City of Seattle Urban Forest Stewardship Plan 2013.

City of Seattle Urban Forest Stewardship Plan 2013.

Colunga-Garcia, M., R.A. Haack, and A.O. Adelaja. 2009. Freight Transportation and the Potential for Invasions of Exotic Insects in Urban and Periurban Forests of the US. J. Econ. Entomol. 102(1): 237-246 (2009); and raw data for the study provided by the authors.

Haack, R.A., F. Herard, J. Sun, J.J. Burgeon. 2009. Managing Invasive Populations of Asian Longhorned Beetle and Citrus Longhorned Beetle: A Worldwide Perspective. Annu. Rev. Entomol. 2010. 55:521-46.

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

Harriger, K. 2014. Presentation to the Continental Dialogue on Non-Native Forest Insects and Diseases, November 3, 2014

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

Nowak, D.J., R.E. Hoehn III, D.E. Crane, J.C. Stevens, J. T. Walton. 2007. Assessing Urban Forest Effects and Values: San Francisco’s Urban Forest. USDA Forest Service. Northern Research Station. Resource Bulletin NRS-8.

posted by F.T. Campbell

Alarming Genetic Variability Appears in SOD in Oregon & – as of 2020 – in California

Oregon authorities have announced that a dying tanoak detected by an aerial survey in the quarantine zone in Curry County, Oregon has proved to be in the EU1 clonal lineage. This is the first report of the EU1 lineage in North American forests. All other isolates of the causative pathogen Phytophthora ramorum in North American forests are the NA1 lineage. [See below for a discussion of P. ramorum clonal lineages.]

Dying tanoak (in California). Photo by F.T. Campbell
The infected tree is near a small private nursery that had been reported infested with the EU1 lineage of P. ramorum in 2012. The nursery carried out the APHIS-mandated Confirmed Nursery Protocol, then closed. Genetic testing suggests this nursery is the probable source population for the EU1infestation of the tree.This incident conveys several lessons:

Discovery of the EU1 lineage of P. ramorum in the forest appears to confirm that nursery infestations can infect plants in the forest.
The importance of genetic testing of samples from every infestation to determine which clonal lineage is present.

The discovery has troubling implications: The EU1 lineage consistently is a more aggressive pathogen than the NA1 clonal lineage already present in forests in California and Oregon. The EU1 lineage kills several types of conifer trees in Europe, including western hemlock (Tsuga heterophylla).
Furthermore, the EU1 lineage is of the opposite mating type as NA1, creating at least a small potential for sexual reproduction and increased variability in the pathogen population. (Sexual reproduction in P. ramorum can only occur when opposite mating types meet; in the absence if opposite mating types, all reproduction is clonal.)
The Oregon Department of Forestry is attempting to eradicate this small infestation. Host plants on the infested site have been cut and piled and will be burned as soon as wildfire risk abates. (Burning of other, lower priority sites has been delayed by inadequate funding). Authorities will also continue intensive surveys and will monitor soil and vegetation before and after treatment. Some funding for this work will come from the USDA Forest Service Forest Health Protection program and USDA-APHIS.

LINEAGES:
The Phytophthora ramorum pathogen is known to have four separate genetic lineages. The NA1lineage is the form of the pathogen established in forests of California and Oregon. This lineage is also the most common lineage in U.S. nurseries. However, two other genetic lineages are also found in U.S. nurseries: NA2 and EU1 (Coats and Chastagener 2009; Mascheretti et al. 2009). Indeed, NA2 was the most common lineage in Canadian nurseries (Goss et al. 2011).
The EU1 strain is widespread in European nurseries and in tree plantations and wild heathlands of southwest England, Wales, parts of Scotland, and Ireland. In 2012, a new, fourth strain was detected in Northern Ireland and a small area in southwest Scotland. This strain is called EU2.This strain is attacking larch, beech, fir, and hemlock trees at these sites (California Oak Mortality newsletter 2015).

Most EU1 and all EU2 type isolates belong to the A1 mating type, whereas the two North American strains belong primarily to the A2 mating type (Hansen et al. 2003). While P. ramorum apparently reproduces sexually only rarely, the presence of both mating types – in nurseries and especially in forests – does increase the possibility that sexual reproduction will occur. Sexual reproduction would allow the pathogen to evolve and perhaps become more aggressive.

NEW SITUATION:

The EU1 strain was detected in forest trees in Del Norte County, California in autumn 2020. This detection was both the first officially confirmed detection of P. ramorum in Del Norte County and the first detection of the EU1 strain in forest trees in California. The source is unclear. The nearest infestation is 12 miles away in Curry County, Oregon; those trees are infected with the NA1 strain. The nearest known EU1 infestation is about 35 miles away. The site of the California EU1 infestation has minimal California bay laurel (Umbellularia californica). This detection has led to designation of Del Norte County as officially infested; it becomes the 16^th California county so designated. [Information from the California Oak Mortality Task Force newsletter for December 2020, available here.]

SOURCES

California Oak Mortality Task Force newsletter [http://www.suddenoakdeath.org/news-and-events/newsletter-archive/ ] April 2015.

Coats, K. and G. Chastagener. 2009. Understanding the mechanisms behind detections of Phytophthora ramorum in Washington State nurseries and streams utilizing microsatellite genotype information. Fourth Sudden Oak Death Science Symposium, June 15-18, Santa Cruz, CA.

Goss, E.M., M. Larsen, A. Vercauteren, S. Werres, K. Heungens, and N.J. Grünwald. 2011. Phytophthora ramorum in Canada: Evidence for Migration Within North America and from Europe. Phytopathology. January 2011, Volume 101, Number 1. Pages 166-171

Hansen, E.M., P.W. Reeser, W. Sutton, L.M. Winton, and N. Osterbauer. 2003. First Report of A1 Mating Type of Phytophthora ramorum in North America. Plant Disease, October 2003, Volume 87, Number 10. Page 1267.

Mascheretti, S., P.J.P. Croucher, M. Kozanitas, L. Baker, M. Garbelotto.2009.Genetic epidemiology of the Sudden Oak Death pathogen Phytophthora ramorum in Calif.Molecular Ecology 18: 4577-4590.

Posted by Faith T. Campbell

National Parks Failing to Protect Forests

Americans love their National parks and expect the National Park Service to ensure the parks’ natural resources are protected “unimpaired for future generations” – as is required by the Service’ founding law.
Despite these expectations, the National Park Service does not take obvious actions to protect trees in the parks from non-native tree-killing insects and plant diseases.

Horton House plantation ruins, Jekyll Island, GA. (Photo by F.T. Campbell) The two large redbay trees shading the house are now gone, killed by laurel wilt. Use your favorite web browser to see how stark the house is now, denuded of its trees.

At historic sites ranging from Horton House plantation on Jekyll Island, Georgia to the Presidio in San Francisco, trees that create atmosphere & maintain visible links to the past have died.

Even more important is the damage occurring to forests in the “crown jewel” wilderness parks:
• Whitebark pines at high elevations of Yellowstone, Glacier, and Crater Lake National parks have been killed by white pine blister rust (see photo below, of dead whitebark pine at Crater Lake). Photo by F.T. Campbell

• The forests of Great Smoky Mountains and Shenandoah National parks, already damaged by chestnut blight, hemlock woolly adelgid, beech bark disease, and gypsy moth, are now losing their ash trees to the emerald ash borer and their walnut trees to thousand cankers disease.
• Everglades National Park and Big Cypress National Preserve are losing their swamp bay trees to laurel wilt
• Tanoak trees in Muir Woods, Redwood National Park, and Pt. Reyes National Seashore have been killed by sudden oak death
• Ash trees in Sleeping Bear Dunes National Lakeshore in Michigan have been killed by the emerald ash borer.

Forests in other “crown jewel” parks are not yet under attack, but are threatened by nearby pests:
• The black oak trees of Yosemite National Park’s signature Valley are at risk to goldspotted oak borer, which has killed more than 100,000 trees in San Diego county.
The threat is obvious … yet the National Park Service dropped efforts to develop a strategy for addressing it. And the NPS has not adopted a national policy requiring campers to obtain their firewood either in the Park or from nearby vendors.

As explained on the Don’t Move Firewood website, firewood is a highly dangerous commodity, since it can transport tree-killing pests to new, vulnerable areas [see also the report Fading Forests III. Some National parks – including Great Smoky Mountains and Shenandoah – have adopted regulations prohibiting visitors from bringing firewood from long distances. However, other parks – including Yosemite – only ask visitors to avoid bringing firewood. In all cases, the firewood regulation or appeal is buried deep within the park’s website. On a more positive note, campers who reserve a campground on such federal websites as www.reserve.gov receive warnings about firewood when they finalize their reservation.

The National Park Service has developed a Manual providing guidance to park managers that describes the threat from firewood and laws and regulations that relate to natural resource protection. However, the Service has left the decision whether to take action to the individual parks’ superintendents.

I think that such a passive stance betrays the Service’ statutory obligation, as laid out in the Organic Act of 1916: the purpose of the National Park Service is
“to conserve the scenery and the natural and historic objects and the wild life therein and to provide for the enjoyment of the same in such manner and by such means as will leave them unimpaired for the enjoyment of future generations.” [emphasis added]

Next year, the National Park Service celebrates its Centenary. I think it should celebrate this anniversary by adopting regulations requiring visitors to obtain firewood locally and finalizing a strategy for combating tree-killing pests.

SOD in the East

At present, sudden oak death (SOD) is killing trees and shrubs in forests along the Pacific coast from far southern Oregon to Monterey County in California – a stretch of more than 400 miles.

However, numerous tree and shrub species native to forests in the East also are vulnerable to the pathogen. These include several oak trees (northern red, chestnut, white, and pin oaks), sugar maple, black walnut; and such shrubs as mountain laurel and rhododendrons.

While no infestations of SOD have been found in the wild in the East, the pathogen is already present in some nurseries and continues to be transported to disease-free parts of the Southeast in shipments of nursery plants – as described in my previous blog.

Nine eastern states monitor streams to detect the pathogen in water. These states are AL, FL, GA, MS, NC, NY, PA, SC, & TX. As of 2013, six states had detected the pathogen in a total of 11 streams and ponds; all were outside nurseries that had previously had infested plants. These positive streams were distributed as follows: AL-4; FL-1; GA-2; MS-1; NC-1; TX-2.

In 2014, only four states (instead of six) detected the SOD pathogen in at least one stream: AL-4; FL-1; MS-2; and NC-2. Two of these streams were new – one each in AL and FL.

One of the AL detections is in a stream associated with a nursery that had not previously been determined to have infested plants. Authorities plans to sample vegetation near this stream. In the past, once a stream had tested positive, it remained positive in all subsequent years. However, the testing methods are not perfect so some variation in findings can be expected.

Infested plants were found growing in the ground (outside a nursery) at three sites: one each at homes in CT and MA; and a commercial business site in LA. These searches were undertaken because officials knew that these residents or businesses had bought plants from an infested nursery in earlier years.

As noted in my previous blog, SOD has been detected in eight nurseries in the East: ME-1, NY-2, TX-1, VA-4). The TX nursery became infested by plants received from a California nursery. I am very concerned about the presence of the pathogen in four Virginia nurseries, because the Commonwealth falls in the geographic region thought to be most vulnerable to the pathogen [see risk maps in the SOD writeup at http://www.dontmovefirewood.org/gallery-of-pests or in Chapter 5 of Fading Forests III.