invasive species – Page 13 – Center for Invasive Species Prevention

Time to view “Trees in Trouble”!

Andrea Torrice’s film “Trees in Trouble: Saving America’s Urban Forests” depicts the impact of non-native tree-killing insects and diseases.

The film is being broadcast in April as part of Earth Day and Arbor Day programming on the PBS World Channel. Check your local public television station website for their schedule or visit the filmmaker’s site for more information.

Andrea’s film focuses on emerald ash borer in Cincinnati. It explores our connections to the trees and forests in our communities – and the threats to those trees. Featured experts and speakers include Prof. Dan Herms of Ohio State, Jenny Gulcik, a community forestry consultant, and Cincinnati Council member Wendell Young.

Because of the high value of urban trees, these pests’ greatest economic damage is in urban and suburban areas. [See my earlier blogs about the wood packaging pathway and this study: 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)]

Nor is this damage limited to southern Ohio – or even the Northeast broadly. Such pests are usually introduced first in cities – not necessarily ports! – because that is where crates and pallets, imported ornamental plants, and other articles to which pests attach arrive. Furthermore, trees along streets and in yards and parks are often more vulnerable than forest trees to such introduced pests because they are often subject to other stresses such as soil compaction, air pollution, elevated temperatures, and salt exposure. Finally, city trees are often planted as multiple individuals of the same species; when a pest that attacks that species arrives, entire neighborhoods can lose their tree canopy – and the real values that canopy provides.

See the film. Ask your friends to watch it! Be inspired by the film to contact members of Congress to ask that they support programs aimed at preventing tree pest introductions. (These programs are operated by APHIS; see my blog about APHIS’ funding needs posted in March.)

If you want to do more – visit the “resources” page of the filmmaker’s website to obtain toolkits for outreach and hosting an event.

Posted by Faith Campbell

Threats to America’s Magnificent Oaks

Oak trees are immensely symbolic to many people and many are magnificent. Congress even designated the red oak as America’s “national tree”.

Photo of Q. rubra leaves by Becca MacDonald, Sault College; www.bugwood.org

Of course, there are many kinds – from those that span many states to those that grow in just some special areas. USDA’s Plants database lists more than 300 native species for the U.S. alone. Many provide substantial ecosystem services and all parts of the country would be poorer without them.

Despite our oaks’ importance, we are doing far too little to protect them from the full range of non-native insects and diseases that pose threats.

CURRENT THREATS IN THE EAST

In the East (from the Atlantic to the Great Plains), oaks are under attack from at least four non-native pests:

One of these, the European gypsy moth (Lymantria dispar), is the target of major containment and suppression programs operated by USDA Animal and Plant Health Inspection Service (APHIS), the US Forest Service and the states. In fact, the US Forest Service spends half of its entire budget for studying and managing non-native pests on the European gypsy moth. In part, this is because the European gypsy moth is so widespread, with outbreaks from Nova Scotia to Wisconsin and south across eastern Ohio to Virginia. (See the map of EGM range here). It also attacks a wide range of tree and shrub species.

But other oak-killing insects and diseases, some with the potential to be at least as damaging, receive far fewer resources.

Oak wilt (caused by the fungus Ceratocystis fagacearum) is widespread from central Pennsylvania across Iowa, down the Appalachians in West Virginia and North Carolina-Tennessee border, in northern Arkansas and with large areas affected in central Texas. There is an isolated outbreak in New York State. (See map here). According to the US Forest Service, oak wilt is one of the most serious tree diseases in the eastern U.S. It attacks primarily red oaks and live oaks. It is spread by both bark-boring beetles and root grafts.

From Long Island along the coast into Nova Scotia and into central Massachusetts, oaks are being killed by the winter moth (Operophtera brumata). Like the gypsy moth, the winter moth has a wide host range. (For more information, see here). A small program led by Joseph Elkington of the University of Massachusetts has focused on biocontrol. Biocontrol agents have successfully reduced winter moth damage in Nova Scotia and the Pacific Northwest. First results are promising in New England.

CURRENT THREATS IN THE WEST

In the West, millions of oaks have been killed by several pathogens and insects that are established and spreading; and additional threats loom.

Coast live oaks, canyon live oaks, California black oaks, Shreve’s oaks, and tanoaks growing in coastal forests from Monterey County north to southern Oregon that catch fog/rain are being killed by sudden oak death and here. Sudden oak death has killed over one million tanoaks as well as hundreds of thousands of coast live oaks and other trees. In early days of the infestation, Oregon – with considerable help from the US Forest Service – tried to eradicate a small infestation in Curry County. The inherent difficulty in managing a pathogen and interruptions in funding caused that effort to fail. The state is now focused on trying to slow spread of the disease.

In California, coast live oaks, black oaks, and canyon oaks in the southern part of the state – primarily in San Diego County, but also parts of San Bernardino, Orange, and Los Angeles counties – are being killed by goldspotted oak borer and here. At least 100,000 black oaks have been killed in less than 20 years. Neither the State of California nor USDA APHIS has adopted regulations aimed at preventing spread of the goldspotted oak borer, despite oaks being at risk throughout California.

Two more wood-boring beetles threaten oaks in southern California. In five counties in the region, coast live oaks, canyon live oaks, Engelman oaks, and valley oaks – and many other kinds of trees – are being killed by a disease transmitted by the polyphagous and Kuroshio shot hole borers and here. The polyphagous and Kuroshio shot hole borers attack more than 300 plant species, including tree species that anchor the region’s riparian areas as well as half of the trees planted in urban areas of the region.

Also, oaks on the West coast would be attacked by gypsy moths should they reach the area. The risk is two-fold – the Asian gypsy moth continually is carried to the area on ships bearing imports from Asia (as discussed in my blog in March). And the European gypsy moth is sometimes taken across the country on travellers’ vehicles, outdoor furniture, or firewood. Both the West Coast states and USDA search vigilantly for any signs of gypsy moth arrival.

Or course, other non-native pests can also be introduced or spread to new, vulnerable, areas. I have blogged about the risk to the East from sudden-oak-death infested plants moving in the nursery trade (see blogs from July 2015). The polyphagous and Kuroshio shot hole borers might also threaten forests in other warm regions of the country such as the Gulf Coast, where some known and potential host trees grow.

ADDITIONAL THREATS

Two apparent threats have come to our attention recently: fungi in the genus Diplodia and another disease called foamy bark canker. There is some uncertainty whether the insects or pathogens are non-native. Both are apparently closely linked to drought stress.

two Diplodia fungi – Diplodia corticola and quercivora – have been detected in both Florida and California. These fungi were previously known to kill oaks in the Mediterranean region.

According to Mullerin and Smith (2015), one or both of these fungi might be native to North America. Diplodia corticola was first identified in the 1980’s in cork oaks (Quercus suber L.) in Mediterranean countries. It has since been determined to be the cause of mortality in other species of European oaks. D. corticola was first reported in California in 1998 in coast live oak trees (Q. agrifolia) that had been colonized by bark and ambrosia beetles. There, it has been an important factor in the deaths of thousands of acres of coast and canyon live oaks (Q. chrysolepis) since 2002 (Mullerin and Smith 2015). In California, periodic diebacks since the late 1970s have been associated with droughts. Symptoms have mainly shown up in coast live oak (Q. agrifolia), black oak (Q. kelloggii), and valley oak (Q. lobata). Dieback is noticeable in at least 20 California counties, throughout most of the range of coast live oak. (See here.)

The first detection of D. corticola in southern Florida was in 2010; D. quercivora was detected in 2013. In Florida, these fungi attack live oaks (Quercus virginiana). Almost all the symptomatic trees in Florida grow in cultivated settings where they are exposed to various stresses. In addition, most of the state experienced severe drought in 2010, the year reports of dieback began (Mullerin and Smith 2015).

Host range studies indicate that 33 species of oaks and one species of chestnut that grow in the Southeast are vulnerable, to varying degrees, to D. corticola. Oaks in the red oak group (Section Lobatae) are more vulnerable than are white oaks (Section Quercus) (Mullerin and Smith 2015). In the test, the most vulnerable appear to be the following species native to the Southeast: Q. laurifolia, Q. virginiana, Q. geminata, Q. chapmanni, Q. laevis (turkey oak), Q. phellos, Q. pumila, and Q. incana. (source: poster presented by Dreaden, Black, Mullerin, Smith at the 2016 USDA Invasive Species Research Forum.)

It is unknown how Diplodia corticola & Diplodia quercivora colonize oaks. However, members of the family (Botryosphaeriaceae) generally enter plants through wounds, including leaf scars, or stomata open for gas exchange. They often live harmlessly as endophytes within the plant, becoming pathogenic when the plant is stressed by environmental factors such as drought, flooding, heat, freezing, herbicide use, or soil compaction (Mullerin and Smith 2015).

Foamy bark canker is new disease of oak species caused by a newly discovered species of species of fungus (Geosmithia pallida). The pathogen is vectored by the Western oak bark beetle (Pseudopityophthorus pubipennis). The disease complex has great potential to cause extensive damage to oaks in California. Still little is known about the disease’ overall distribution, establishment and incidence.

Declining coast live oak trees have been observed since 2012 throughout urban landscapes in Los Angeles, Orange, Riverside, Santa Barbara, Ventura, and Monterey counties in California. Fungal colonies were observed within beetle galleries (Lynch et al. 2014). The Western oak bark beetle is thought to be a native. It commonly attacks trees weakened by other agents; it has not previously been associated with disease. However, the disease vector might be a different, similar beetle; scientists are collecting more, from a larger geographic area, to determine whether it is the native species or something else. In Europe, the fungus appears to have be associated with a range of bark-boring insects and is widely distributed. There is no previous published record of the fungus occurring in the United States (Lynch et al. 2014).

Symptoms can be viewed here.

SOURCES

Dreaden, T. A. Black, S. Mullerin, and J. Smith risk to oaks from Diplodia cor+cola and D. quercivora, two emergent fungal pathogens (poster at Annapolis 2016) Includes map showing distribution in Florida.

Drill,S. New pest alert for Foamy Canker Disease on Coast Live Oak. 2014. http://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=13707

Lynch, S.C., D.H. Wang, J.S. Mayorquin, P.F. Rugman-Jones, R. Stouthamer, A. Eskalen. 2014. First Report of Geosmithia pallida Causing Foamy Bark Canker, a New Disease on Coast Live Oak (Quercus agrifolia), in Association with Pseudopityophthorus pubipennis in California. APS Journals Plant DiseaseSeptember 2014, Volume 98, Number 9 Page 1276 http://apsjournals.apsnet.org/doi/abs/10.1094/PDIS-03-14-0273-PDNhttp://apsjournals.apsnet.org/doi/abs/10.1094/PDIS-03-14-0273-PDN

Lynch, S., S. Rooney-Latham, A. Eskalen. [DATE?] Foamy Bark Canker A New Insect-Disease Complex on Coast Live Oak in California Caused by Western Oak Bark Beetle and Geosmithia sp.

Mullerin, S. & J.A. Smith. 2015. Bot Canker of Oak in FL Caused by Diplodia corticola & D. quercivora. Emergent Pathogens on Oak and Grapevine in North America. FOR318

Posted by Faith Campbell

Eradicate ALB – of course! But what about the other pests?

The Asian longhorned beetle (ALB) is the target of most of APHIS’ spending on non-native, tree-killing insects and pathogens. I have been on the record for 18 years – representing a sequence of three organizations – supporting ALB eradication efforts. But other damaging pests do not get adequate attention. Much of the explanation is probably money – APHIS is inadequately funded. But why have the other tree-killers slipped from the attention of politically important constituencies? How do we reverse this situation so that needed actions are taken?

The ALB Eradication Effort

After consulting several sources — Haack 2009, periodic news releases by APHIS and the Ohio Department of Agriculture – I conclude that in the 20 years since ALB was detected in Brooklyn in 1996, US and Canadian authorities have removed at least 188,000 trees. Data on the numbers of high-risk trees treated with systemic pesticides are much less complete. However, it appears from these same sources that U.S. and state authorities have treated more than 800,000 trees. Easily available data do not reveal how many of the treated trees were later found to be infested and therefore had to be cut down. I do hope agency and academic scientists are tracking that information – it is crucial to evaluating the efficacy of programs that allow treatment of “high risk” trees instead of removing them. A related issue is how many trees at early stages of infestation are missed by surveyors.

In carrying out the eradication program over 20 years, APHIS has spent about $600 million (Santos pers. comm.; US Department of the Interior 2016). Canada has spent far less – something more than $35 million Canadian (Marcotte pers. comm.).

In FY15 APHIS allocated $41.6 million to eradication of the Asian longhorned beetle [US DoI 2016]. This represented 77% of all funds in the agency’s “Tree and Wood Pests” account. The President’s FY17 budget calls for cutting funding for this account from its current level of $54 million to $46 million. If Congress accepts President’s proposed cut and funding for ALB eradication remains at the FY15 level, the proportion allocated to this one pest would rise to 90% of the total account. Perhaps APHIS anticipates spending less on the ALB program. APHIS has announced (USDA news release) that it will no longer apply systemic pesticides to “high-risk” trees in order to prevent beetle infestation. Instead, the program will focus on identifying and removing infested trees. I worry that with ALB outbreaks still present in Massachusetts, New York, and Ohio, any reduction in the program would be risky. (Official USDA budget documents don’t provide an explicit funding level for the ALB program, so we can’t be sure whether cuts are planned.)

Certainly, ALB eradication deserves continued priority. The beetle kills trees in 15 botanical families – especially maples and birches, which constitute much of the hardwood forest reaching from Maine to Minnesota, as well as urban trees worth an estimated $600 billion. Furthermore, adequately funded eradication efforts have proven to be a successful tactic.

pshb_1 PSHB damage to coast live oak;

photo by Akif Eskalen, UCRiverside

Other tree-killing insects are being ignored

However, other species need to be addressed, too. If these efforts are to succeed, they need more than the leftovers from funding ALB work.

Some funds are available through the Farm Bill Section 10007 “Plant Pest and Disease Management and Disaster Prevention Program” grant program. Still …

The Asian gypsy moth demands constant attention from APHIS. That effort is ramping up in response to moth detections in the Pacific Northwest. Apparently most of the funds for this program are from the Farm Bill Section 10007 program – but how long can this funding source be sustained? (See my blog posted earlier in March.)

Efforts to eradicate the spotted lanternfly (Lycorma delicatula) from Pennsylvania continue. The lanternfly attacks 25 or more plant species that grow in the Mid-Atlantic states. Concern focuses on grapes and fruit trees including apples and stone fruits. (The lanternfly prefers tree of heaven (Ailanthus) (PA DoA) but the insect’s host range is too wide to use it as a biocontrol agent for this widespread invasive plant. The spotted lanternfly entered country as egg masses attached to imported slate. It has been detected in four counties in southeastern Pennsylvania ]

What is – or should be – done about the 20 species of non-native wood-boring and bark insects that have been detected for the first time in the United States over just the past decade? While some appear not to be causing major damage, that impression could be wrong. The polyphagous shot hole borer was first detected in California in 2003 ]. It has taken over 10 years to determine that the PSHB and very similar Kuroshio shot hole borer transport fungi that threaten over 300 plant species, including trees that make up the majority of trees in riparian areas and half of the trees planted in urban areas across southern California.

Tree species in other warm regions of the country such as the Gulf Coast are also at risk if the shot hole borers’ spread is not curtailed. Examples include native boxelder and American sweetgum; as well as such widely planted ornamentals as camellia, mimosa, and Japanese maple. The insects and the Fusarium pathogen that they transport might also attack other species in the oak, maple, sycamore, holly, and willow genera which grow in the Southeast.

Other funding needs

APHIS needs to continue efforts to slow the spread of and reduce impacts on forests from the emerald ash borer, including by continuing to support programs aimed at curtailing movement of firewood. While the emerald ash borer has spread to 25 states, significant areas of natural and urban ash forests remain pest-free, especially in the deep South, Great Plains, and Pacific Coast. APHIS might also continue funding research aimed at improving both biological control and breeding of ash trees resistant to the emerald ash borer. See my blog about resistance breeding posted in February.

APHIS must also have sufficient resources to respond when additional insect introduction are detected – which seems likely since an estimated 35 shipping containers entering the country each day carry wood packaging infested by damaging pests. [see my blogs about wood packaging posted in July and August 2015 and the SWPM fact sheets.

And – as the AGM and spotted lanternfly examples demonstrate – the risk of introduction of tree-killing insects goes far beyond imports of “agricultural” commodities – even when those commodities are widely interpreted to include wooden crates and pallets.

Please re-visit my blogs of 22 February to learn the details of funding issues and then contact your Representative and Senators to support increased funding for APHIS.

Posted by Faith Campbell

SOURCES

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

Marcotte, M. Canadian Food Inspection Agency. Email to F.T. Campbell 29 April, 2013.

Pennsylvania Department of Agriculture: Agriculture Secretary Urges Consumers to Help Keep Foreign Insect from Spreading through Pennsylvania, United States News for Immediate Release Nov. 3, 2014

Santos, R. USDA Animal and Plant Health Inspection Service. Email to F.T. Campbell, April 12, 2013.

USDA APHIS NEWS RELEASE 3/28/16

Contact: Rhonda Santos, (508) 852-8044, rhonda.j.santos@aphis.usda.gov

Suzanne Bond, (301) 851-4070, suzanne.m.bond@aphis.usda.gov

U.S. Department of the Interior. 2016. Safeguarding America’s lands and waters from invasive species: A national framework for early detection and rapid response, Washington D.C., 55p.

Asian gypsy moth – the risk is still too high

The Asian gypsy moth would be more damaging than the European gypsy moth because it feeds on a wider range of plants – including conifers – and the female flies – speeding up its spread.

Asian gypsy moth; John H. Ghent; bugwood.org

The United States and Canada have a joint program – under the auspices of the North American Plant Protection Organization (see RSPM #33 here) aimed at preventing introduction of species of gypsy moths native to Asia. The principal risk arises from moths attaching their egg masses to ships (and containers on deck) when the ships visit ports in Far Eastern Russia, China, Korea, and Japan. The NAPPO standard originally went into force in March 2012. Under its terms, ships leaving ports in those countries during gypsy moth flight season must be inspected and cleaned before starting their voyage.

Gypsy moth populations rise and fall periodically; thus, it is much more likely that egg masses will be attached to ships during years of high moth population densities.

These variations are seen in U.S. and Canadian detection reports.

AGM Interceptions by year

United States Canada

2010 4

2011 21

2012 44 32

2013 42 33

2014 76 39

2015 7 15

(U.S. data from Kevin Harriger, Bureau of Customs and Border Protection, at the 2015 meeting of the Continental Dialogue on Non-Native Forest Insects and Diseases [http://continentalforestdialogue.org/continental-dialogue-meeting-november-2015/] ; Canadian data from Wendy Asbil, National Manager, Invasive Alien Species and Domestic Plant Health Programs Section, Plant Health and Biosecurity Directorate, Canadian Food Inspection Agency

While most AGM detections are at West Coast ports, the risk is not limited to that region. In 2013, Asian gypsy moths were detected at Baltimore, MD; Charleston, SC; Savanna and Brunswick, GA; Jacksonville, FL; New Orleans, LA; Houston and Corpus Christi, TX; and McAlester, OK.

Well aware of the risk associated with ships, U.S. and Canadian customs officials are vigilant in conducting inspections; if egg masses are found, the ships are required to return to international waters and clean off the egg masses. The ships are inspected again before they are allowed back into port. The process delays deliveries that are often on tight schedules and costs hundreds of thousands of dollars.

However, the risk is not limited to the ships themselves. In 2014, more than 500 Asian gypsy moth egg masses were found on four shipments of imported steel slabs arriving at ports on the Columbia River. Efforts were made to clean the more than 5,000 steel slabs, but some egg masses were still present after the cleaning. The steel was then sent to a furnace for final processing; the furnace heated the steel to more than 2,000^oF – sufficient to kill any remaining eggs! Still … (report by APHIS: Asian Gypsy Moth interceptions and mitigation of risk at Columbia River Ports of Entry, 2014. 18 February 2015)

Some question whether a global company with annual earnings close to $2 billion can be persuaded to take the necessary steps to ensure that its imports are free of gypsy moth eggs. The cleanup costs charged by APHIS would be minimal.

Besides, cleaning large steel plates is apparently difficult and probably requires fumigation with methyl bromide – which must be administered in a closed facility with appropriate safety measures.

Implementing the NAPPO standard that presents a unified front to Asian exporters – they must clean ships headed to North America – clearly has reduced the risk of introduction of Asian gypsy moths. But the smaller risk remains. Indeed, Oregon and Washington occasionally catch small numbers of Asian gypsy moths in their traps. In 2015, ten Asian gypsy moths were trapped in Washington State (Report of the Technical Working Group for the Response to Asian Gypsy Moth Captures Washington-Oregon 2015 October 30, 2015).

Oregon caught two Asian gypsy moths in the Portland area (15,000 traps had been placed statewide; the state also trapped 12 European gypsy moths). Previous detections of Asian gypsy moth in Oregon were one each in 1991, 2000, and 2006. Two of these moths were trapped near the location of the 2015 detections. A vessel that called at Tacoma in January 2013 had 275 egg masses.

The Asian gypsy moths were caught in traps across a broad area, including eight captures around southern Puget Sound and three in the Portland, OR/Vancouver, WA area. For these and other reasons, experts concluded that it is likely that females moths are also present in one or more of these areas (Report of the Technical Working Group for the Response to Asian Gypsy Moth Captures Washington-Oregon 2015 October 30, 2015).

The expert group recommended enhanced trapping plus eradication at the four sites where captures were clustered. The group discussed the pros and cons of various approaches, including spraying with Btk, Diflubenzuron (“Dimilin”), or Tebufenozide (“Mimic”); or with Gypchek (gypsy moth nuclear polyhedrosis virus); and augmentation of spray programs by releasing sterile males.

Both Washington and Oregon plan gypsy moth eradication measures in 2016. Washington plans to treat 10,500 acres at seven locations in Pierce and Thurston counties (both at the southern end of Puget Sound). Oregon will spray in several places in northern and northwest Portland.

Posted by Faith Campbell

Invasive Plants: a major threat to forests of the East

Go anywhere in the woods of the East, you are likely to see Japanese or shrub honeysuckles, multiflora rose, privets, Japanese stiltgrass, garlic mustard, Chinese tallowtree, … .

Japanese honeysuckle; Chuck Bargeron; Bugwood.org

A new study confirms how widespread these invasive plants are.

Christopher Oswalt and colleagues (2016) have studied the data from the national Forest Inventory and Analysis (FIA) program of the United States Forest Service. They found that almost 40% of forests in the United States are invaded by alien plant species. Furthermore, forests in the eastern United States have been invaded by more invasive plant species than those in the West.

Large numbers of invasive plants are established in the United States. As I noted in this blog in January, nearly 10,000 non-native plant species are present, although not all are invasive. (See Rod Randall’s report here ).
The USDA Forest Service develops region-specific lists in consultation with invasive plant experts. Then the authors normalized the data by calculating the proportion of forested subplots in each county with at least one invasive species present. Oswalt and colleagues then used this percentage to define invasion intensity for those plots that contain any invasive plants on the region or state-specific monitoring lists. They mapped the subcontinental spatial distribution of invasive plants based on this measure of “invasion intensity”.
Nationwide, 39% of forested plots sampled contained at least one invasive species. There are significant regional differences. To no-one’s surprise, Hawai`i had the highest invasion intensity – 70%. Second highest density is in the eastern forests – 46%. Forests in the West ranked third, with 11% of plots containing at least one of the monitored invasive plant species. Finally, forests in Alaska and the Intermountain regions both had 6% of plots invaded. This finding might surprise some because of the level of political attention given to plant invaders on grazing lands in the West.
The authors attributed clusters of more highly invaded counties to disturbance, e.g., fragmentation in the North Central region and major travel corridors in the Piedmont of the Southeast.
I would rephrase the principal cause as “propagule pressure”. While forests of the East are certainly small and surrounded by other land uses – that is, fragmented – these are also areas where invasive plants have been extensively planted – some for nearly a century. Some – e.g., honeysuckles, multiflora rose, and lespedeza – were intentionally planted in woodlots as food or cover for wildlife.
Another factor is the great diversity of invasive plant species present in the East and thus available to spread into the forest by such mechanisms as transport of seed by birds and other wildlife. The Southeast Exotic Pest Plant Council maintains a list of approximately 400 invasive species. The Mid-Atlantic Invasive Plant Council has a list of 285 invasive plants. Many of the invaders in both lists are herbs, shrubs, or trees which can invade shaded environments.
The top five most frequently detected invasive plants in the Southeast were Japanese honeysuckle, privets, roses, lespedeza, and microstigium. The first four have been deliberately planted either directly in “natural” areas or in yards and gardens throughout the region. The top five species for the Northeast and Midwest are multiflora rose, reed canary grass, garlic mustard, Japanese honeysuckle, and common buckthorn. Again, four of these have been widely planted deliberately. Note that few of these species’ seeds are spread by wind.

In contrast, the top five species in the Intermountain West are less frequently planted intentionally: cheat grass, Canada thistle, spotted knapweed, houndstongue, and musk thistle. Invasive plants in forests of the Pacific states fall between these poles, as they include planted species, such as Armenian blackberry, and unplanted ones, such as cheat grass and medusahead.

Clearly the threat from invasive plants is great and growing (see my blogs from January for discussions of other aspects of the problem). What should we do to counter it?
• Those who sell plants for any use – ornamental horticulture, ground cover, livestock forage, soil amelioration, wildlife habitat management, biofuels – should commit to avoiding species that are known or suspected to be invasive in the region.
• Voluntary efforts to limit sales of invasive plants have fallen by the wayside. The various Invasive Plant Councils should work with industry groups and others to renew this effort. Also, the Councils should propose a joint list of additional plants for APHIS regulation under NAPPRA (see below).
• Those who buy plants for these various uses should make a similar commitment – especially large, institutional buyers like state highway departments.
• Concerned citizens should lobby their state governments and the Congress to fund ongoing “noxious weed” programs and to ensure that these programs include plant species that threaten natural areas, not just weeds of agriculture.
• Concerned citizens should lobby the Congress to increase funding for federal agencies’ invasive plant control programs, especially those addressing natural areas, and especially in Hawai’i and the eastern United States. Also, the U.S. Department of Agriculture needs to adopt procedures that enable APHIS to act more quickly to curtail introduction and human-assisted spread of invasive plants. Most urgently, APHIS should finalize the May 2013 proposal to restrict importation of 22 species under the NAPPRA program (see my blog “Invasive plants – huge numbers! Continuing spread …” from January and the description of the NAPPRA program here).
Source
Christopher M. Oswalt, Songlin Fei, Qinfeng Guo, Basil V. Iannone III, Sonja N. Oswalt, Bryan C. Pijanowski, Kevin M. Potter 2916. A subcontinental view of forest plant invasions. NeoBiota. 24: 49-54 http://www.srs.fs.usda.gov/pubs/48489

Posted by Faith Campbell

Feral Hogs: numbers climbing, threats to soils & ecosystems increasing, no control in sight

Introduced wild hogs (Sus scrofa) threaten ecosystems across the continent and on islands ranging from Hawai`i to the Caribbean.

large_hog_damage (MO) feral hogs in Missouri

Pigs are the ultimate survivors – highly adaptable and prolific. Most of the damage is done by their rooting for plant parts and invertebrates in the soil, and by wallowing to cool themselves and fend of biting insects. Depending on soil type (density, moisture level, compaction), pigs may root to depths of three feet below the surface (USDA APHIS EIS).

Feral hogs consume primarily plant matter. They prefer hard mast – e.g., acorns, beechnuts, chestnuts, or hickory nuts. Pigs can be formidable competitors with native wildlife for this nutritious food. Feral hogs also eat algae, fungi, invertebrates such as insects, worms, crustaceans, and bird and reptile eggs. In addition, they feed on small animals, including reptiles, fish, amphibians, ground-nesting birds, and young of wild game and domestic livestock. They even feed on larger animals – although it is not clear whether they kill such animals or only scavenge their carcasses (USDA APHIS EIS).

Since pigs lack sweat glands, they wallow in water and mud to cool off. Some wallow sites are used for years. Adjacent areas are usually denuded of vegetation and the soils are compacted. Wallows are commonly located in or adjacent to riparian or bottomland habitats (USDA APHIS EIS).

Despite the apparent damage, only a few studies address the feral hogs’ impacts on soil structure, chemistry, bulk density and nutrient cycling. The conclusions of those studies are mixed (USDA APHIS EIS).

In Great Smoky Mountains National Park, feral pigs are reported to “plow up” areas in search of bulbs, tubers and wildflowers and to consume small mammals, snakes, mushrooms, bird eggs, and salamanders. (The Smokies are a center of endemism for salamanders.) Wallows are said to contribute significantly to stream sedimentation, thereby harming aquatic life.
Furthermore, feral hogs contribute to both human and animal disease. Their feces contaminate water and soil with coliform bacteria and Giardia which are both a threat to human health. Some of the wild pigs also carry Pseudorabies, a disease that is almost always fatal to mammals, including such important wildlife species as black bear, bobcat, elk, white tailed deer, red fox, grey fox, coyote, mink, and raccoon. Pseudorabies from wild boar can survive in humid air or water for up to seven hours and in plants, soil, and feces for up to 2 days.

Unfortunately, the United States’ population of introduced wild pigs has dramatically increased since 1990. People are to blame.

States with feral hog populations; provided by John Mayer, US Department of Energy, Savannah River National Laboratory

According to John J. Mayer, the number of states with established wild boar populations has risen from 19 in the 1990s to 37. The total number of feral hogs has risen from an estimated 1 to 2 million animals to a range of 4.4 to 11.3 million (Mayer).

The overwhelming majority of the feral hogs is found in only 10 states –AL, AR, CA, FL, GA, LA, MS, OK, SC, TX. Texas has the largest numbers, 30 to 41% of the U.S. total, depending on whether one is counting the states’ animals by mean, maximum, or minimum estimates.

Why have people transported feral pigs to so many new places over the last 20 years? Largely because hunters wanted an exciting game animal to pursue (USDA APHIS EIS; Mayer). In Tennessee, populations of feral swine (probably released by farmers to forage for themselves) were relatively stable and confined to only a few counties from the 1950s through the 1980s. However, since a statewide, year-round, no bag-limits hunting program was instituted in 1999, pig populations have expanded rapidly. In 2011, nearly 70% of counties had pockets of feral swine (USDA APHIS EIS).

But hunting is not an effective means of controlling the animals’ populations and damage. Mayer reports that sport hunters remove about 23% of a wild pig population annually. Models demonstrate that 50 – 75% of a wild pig population must be removed annually, year after year, in order to reduce or eradicate that population (J.J. Mayer pers. comm]

Mayer says there are currently no effective management tools or options to reduce or control feral hog populations in most situations. I note that the Hawaii Volcanoes and Haleakala National parks have been able to eradicate feral pigs through determined efforts.

Missouri is one state that is tackling feral hogs aggressively. In January, the Missouri Conservation Commission approved changes to the Wildlife Code of Missouri that would prohibit the hunting of feral hogs on lands owned, leased, or managed by the Missouri Department of Conservation. A public comment period on the proposed regulation change will run from April 2 through May 1. After considering the citizen input and staff recommendations, the Commission will reach a decision whether to finalize the new regulation – probably in September. (Missouri has quite extensive material on feral hogs posted here
Meanwhile, the Missouri Department of Conservation has reached out to several partners to strengthen its increase the number of feral hog traps it can place and enhance communication to the public. These partners include such agricultural organizations as the Missouri Farm Bureau and Missouri Pork Producers; and such conservation organizations as the National Wild Turkey Federation and two quail associations.

New York has gone farther; it has adopted a policy of eradicating Eurasian wild boar from the state. To achieve this goal, the state in October 2013prohibited importing, breeding, or releasing Eurasian boars. As of September 2015, it has been illegal to possess, sell, distribute, trade or transport Eurasian boars in New York. Hunting or trapping of Eurasian boars is illegal except for law enforcement officers, farmers, and landowners authorized by the Department of Environmental Conservation (DEC). The hunting ban was adopted in order to minimize breakup of sounders so as to facilitate eradication trapping by trained conservation officers. For more information, visit the DEC website.

Sources
Mayer, J.J. 2014. Estimation of the Number of Wild Pigs Found in the Unted States. August 2014 SRNL-STI-2014-00292, Revision 0.

U.S. Department of Agriculture Animal and Plant Health Inspection Service
Final Environmental Impact Statement. Feral Swine Damage Management: a National Approach May 27, 2015

Click to access 2015%20Final%20EIS%20Feral%20Swine%20Damage%20Management%20-%20A%20National%20Approach.pdf

Posted by Faith Campbell

Support Higher Funding Levels for Key APHIS & USFS Programs

The President’s proposed Fiscal Year (FY)17 budget once again proposes to reduce funding for APHIS and USDA Forest Service. These are the programs that protect our trees and forests; these are the programs that try to prevent introductions of tree-killing insects and disease pathogens, and to counter the damage they cause once introduced.

Congress is expected to act beginning this spring; we need Congress to enact adequate funding for these programs in FY17 – which begins in October.

I provide below the FY15 & FY16 funding levels and the President’s proposed FY17 level. I also suggest more appropriate funding levels for these programs.
Please contact your Representative and Senators by mid-March and ask him or her to support higher funding for these crucial programs. Your voice is particularly important if your Representative or Senator sits on either the Agriculture or Interior Appropriations subcommittees (listed below).
Fiscal Year Funding for Key Programs (funds are given in millions of dollars)

APHIS (I apologize – columns don’t line up!)
FY15 FY16 FY17 (Pres’ request) $needed

Plant Health (total)       305         314           288
Specialty crops               156        164           146            164
Tree & wood pests           54          54              46               54

The “Tree & wood pests” account funds all APHIS efforts to contain or eradicate the Asian longhorned beetle and emerald ash borer; much smaller programs targeting walnut twig beetle/thousand cankers disease, laurel wilt, and polyphagous shot hole borer [all described here as well as the agency’s involvement in firewood and other slow-the-spread campaign. Even at the $54 million funding level, APHIS is already ignoring many established pests … and its ability to respond to new introductions is severely restricted. With the continuing presence of damaging wood-borers in incoming crates and pallets (See earlier blogs discussing the wood packaging pathway posted in August, September, and October; and Chapter IV of Fading Forests III, now is not the time to cut funding for this program.

The “specialty crops” account includes a small amount of funding (in past years, approximately $5 million) to support APHIS’ program aimed at preventing spread of sudden oak death through movement of nursery stock. (For discussions of this risk see my earlier blogs from July and August and Chapter IV of Fading Forests III.

The budget justification notes that “cooperators who directly benefit from … activities [under the Tree and Wood Pests and Specialty Crop Pests programs] will need to increase contributions to achieve the same level of program operations. Even with the proposed decreases, APHIS will continue to pay between 47 percent and 80 percent of the costs of the programs. …” The Office of Management and Budget has long tried to reduce the federal share of pest containment costs. I counter: is it not appropriate that the agency with the legal responsibility for preventing and containing pest introductions bear the cost of responding when pests are introduced nevertheless?

Fiscal Year Funding for Key Programs (funds are given in millions of dollars)

USFS (I apologize – columns don’t line up!)
FY15 FY16 FY17 Pres’ request needed
Forest Health Protection (total)

104.57         99.6             92.06           100?
Federal lands    58.922        58.922       51.382
Coop lands         45.655        40.678       40.678         48
FHP funds the Forest Service’ assistance to federal partners (e.g., National Park Service) and non-federal entities (e.g., states, cities, private land managers) for management of forest pests – both native and alien species. The FY17 budget justification does not provide a breakdown of spending by species. The FY16 President’s request allocated only $12 million (13% of total funds) to specific projects targeting non-native insects or pathogens. More than $7 million of these funds went to just one species – European gypsy moth. Please advocate for a higher proportion to go to non-native pests.

Research (total) 296 291 291.982 300?
Forest Inventory 70 75 77 83

The USFS Research and Development program provides most of the funds for research to understand non-native pests’ pathways of introduction and spread and biological impacts. These funds also support most of the efforts to breed resistance into tree species and some of the work on other control methods, such as chemicals and biocontrol. The FY17 budget justification does not provide a breakdown of spending by species; the FY16 President’s request allocated only $5 M (less than 2% of total funds) to projects targeting non-native insects or pathogens. Please advocate for a higher proportion to go to non-native pests.

Members of key House & Senate Appropriations Subcommittees
Agriculture Appropriations Subcommittees (fund APHIS):
House: Aderholt (AL), Yoder (KS), Rooney (FL), Valadao (CA), Harris (MD), Young (IA); Farr (CA), DeLauro (CT), Bishop (GA), Pingree (ME)
Senate: Moran (KS), Blunt (MO), Cochran (MS), McConnell (KY), Collins (ME), Hoeven (ND), Daines (MT), Merkley (OR), Feinstein (CA), Tester (MT), Udall (NM), Leahy (VT), Baldwin (WI)

Interior Appropriations Subcommittees (fund USFS):
House: Calvert (CA), Simpson (ID), Cole (OK), Joyce (OH), Stewart (UT), Amodei (NV), Jenkins (WV); McCollum (MN), Pingree (MD), Kilmer (WA), Israel (NY)
Senate: Murkowski (AK), Alexander (TN), Cochran (MS), Blunt (MO), Hoeven (ND), McConnell (KY), Daines (MT), Cassidy (LA); Udall (NM), Feinstein (CA), Leahy (VT), Reed, Tester (MT), Merkley (OR)

Posted by Faith Campbell

How should regulators address strains of pathogens?

Species of tree-killing pathogens can have several “strains” that may vary in virulence or hosts affected.

`ohi`a tree on Hawai`i

This is a phenomenon well known to pathologists, but regulators have not adapted their programs to address it. Once a pathogenic species is determined to be established in the country, APHIS considers the entire species to be “non- actionable” and will not attempt to prevent introduction of any new strains. As the examples below illustrate, allowing introduction and spread of new strains poses risks to North America’s trees.

World-renowned British forest pathologist Clive Brasier has spoken out often on the risk posed by various strains of a pathogen. He has also written about the potential for pathogen species to hybridize and for that hybrid to threaten new hosts.

How widespread a problem is this? Some of the pathogens causing the greatest damage have several strains that vary in their virulence and host range.

The sudden oak death pathogen, Phytophthora ramorum is known to have four strains: NA1, NA2, EU1 and EU2. The EU1 lineage has primarily been found in European nurseries and forests. It has also been recovered from several nurseries and waterways on the U.S. west coast. Last year, the EU1 lineage was detected in a forest in Oregon (see my blog posted 15August 2015). This is troubling for two reasons:
* the EU1 lineage is more aggressive than the NA1 lineage already present in the forests of California and Oregon. Some of the individual tree which now appear to be resistant to the NA1 lineage might succumb to the EU1 lineage.
* The EU1 and NA1 lineages belong to opposite mating types, so they can potentially reproduce, thereby increasing the genetic variability of the pathogen. (Sexual reproduction in P. ramorum can only occur when opposite mating types meet; in the absence of opposite mating types, all reproduction is clonal.)

• The guava rust or myrtle rust pathogen, Puccinia psidii, also has several strains which vary in their virulence. Already, a new strain introduced to Jamaica in the 1930s caused extensive damage to the allspice industry – although a different strain had been on the island for decades (Carnegie 2016).

Hawaiian conservationists worry that a more virulent strain of P. psidii might be introduced and threaten additional species of Myrtaceae on the Islands – especially the `ohi`a tree which is the major canopy tree in 80% of the Islands’ remaining native forest. These forests are key to maintaining the Islands’ watersheds and biodiversity, especially because `ohi`a nectar is the principal food source for many of the remaining native and rare bird species. (See writeup here)

Multiple strains of `ohi`a rust have been identified in the pathogen’s native range of Brazil. Using funds from the USDA Forest Service, scientists in Brazil (Costa da Silva et al. 2014) tested five of the strains; three proved to be highly virulent on most `ohi`a seedlings tested. `Ohi`a from several locations were tested; none showed significant resistance to these three strains of the P. psidii pathogen.

The tests were carried out under conditions highly conducive to infection, so the results cannot be used to predict epidemiological behavior and ecological ramifications in natural conditions. Nevertheless, the results do support the need for greater efforts to prevent introduction of new strains to the Islands.

Additional tests are under way to determine whether the Brazilian strains are more virulent than that strain currently found in Hawai`i and to learn more about possible variation in vulnerability among `ohi`a trees from a greater variety of sites.
• The pathogen that causes Port-Orford cedar root disease (Phytophthora lateralis) has now been found to have four lineages. Scientists compared isolates from the pathogen’s putative native range on Taiwan to isolates from the North American west coast (where it has been established since early in the 20th Century) and Europe (where it began killing trees in the 1990s). They found one slow- growing strain from Taiwan, one fast-growing strain from North America and Europe, and one of intermediate growth from a small area of the United Kingdom (Brasier et al. 2012).

Sometimes, pathogens behaving in unexpected ways are initially thought to be a strain or lineage, but are later classified as a novel species. Thus the Ceratocystis causing `ohi`a wilt was initially thought to be a strain of C. fimbricata, a widespread fungus that has been on the Hawaiian Islands for decades. Scientists now think it is a new species (Keith 2016).

Pathogens are difficult to manage. The vast majority of species remain undescribed. They are difficult to detect until they cause noticeable damage. For a longer discussion of the challenges posed by pathogens and other unknown organisms, read Chapter 3 of Fading Forests II, available here.

However, the great threat to our forests necessitates that APHIS and other phytosanitary agencies (in states and around the world) develop improved methods for addressing the challenge that pathogens pose. Our forests simply cannot afford introductions of more tree-killing fungi, oomycetes, and other pathogens.

At a minimum, APHIS should respond to evidence that a particular pathogen is composed of multiple strains with varying virulence by agreeing to designate such novel strains as “actionable” and applying all its authorities and powers to prevent introduction and spread of the novel strains.

As I noted in my blog of earlier this month, APHIS also needs to develop more effective strategies for addressing introduction and spread of pathogens generally. USDA should assist such efforts to improve controls over pathogens by bringing about prompt finalization of two APHIS initiatives:
1) Prohibiting temporarily plants suspected of transporting known damaging pathogens. This action is allowed under the NAPPRA (not authorized for importation pending pest risk assessment) program.
2) Requiring foreign suppliers of living plant imports to implement “hazard analysis and critical control point” programs to ensure that the plants are pest-free during production and transport. This approach is allowed under ISPM#36 and would be authorized under pending changes to APHIS’ “Q-37” regulation. (See Federal Register Vol. 78, No. 80 April 25, 2013.)

(See longer discussions of these programs in Fading Forests III, available here.)
Sources

Clive M. Brasier, C.M, S. Franceschini, A.M. Vettraino, E.M. Hansen, S. Green, C. Robin, J.F. Webber, and A.Vannini. 2012. Four phenotypically and phylogenetically distinct lineages in Phytophthora lateralisFungal Biology. Volume 116, Issue 12, December 2012, Pages 1232–1249

Carnegie, A.J., A. Kathuria, G.S. Pegg, P. Entwistle, M. Nagel, F.R. Giblin. 2016. Impact of the invasive rust Puccinia psidii (myrtle rust) on native Myrtaceae in natural ecosystems in Australia. Biol Invasions (2016) 18:127–144 DOI 10.1007/s10530-015-0996-y

Costa da Silva, A., Magno Teixeira de Andrade, P. Couto Alfenas, A., Neves Graca, R., Cannon, P., Hauff, R., Cristiano Ferreira, D., and Mori, S. 2014. Virulence and Impact of Brazilian Strains of Puccinia psidii on Hawaiian `Ohi`a (Metrosideros polymorpha). Pacific Science (2014), vol. 68, no. 1:7-56
Keith, L. 2016. Ceratocystis fimbriata, Rapid O’hi’a Death: Unraveling the mystery. 27th USDA Interagency Research Forum on Invasive Species January 12-15, 2016 Annapolis, Maryland

Posted by Faith Campbell

How should APHIS manage pathogens with Multiple Hosts?

large redbay tree on Jekyll Island, Georgia; afterwards killed by laurel wilt

North America and other continents have been invaded by a growing number of tree-killing organisms – primarily pathogens – that attack a wide range of hosts100 species or more. Examples include sudden oak death / Phytopthora ramorum**, laurel wilt**, and the Fusarium fungus transported by the polyphagous and Kushiro borers**. These pathogens are more difficult to manage because of the range of potential hosts. Furthermore, a single introduced species can threaten numerous host species across large areas.
This is not a new phenomenon. Root rot caused by Phytophthora cinnamomi reached North America in the late 18th or early 19th Century, where it eliminated chestnut and chinkapin from low-elevation sites. P. cinnamomi is found in countries around the world. In Australia, it is killing a wide range of trees and shrubs across several plant families that constitute important components of Australia’s flora, including Myrtaceae, Proteaceae, Epacridaceae and Papilionaceae. There have been significant ecological impacts to plant communities and dependent wildlife in southeast and southwest Australia (Carnegie et al. 2016).

Nevertheless, the apparent proliferation of tree-killing organisms with multiple vulnerable hosts is troubling. So is the rapidity with which these organisms have been spread to distant places.

The disease called variously guava, eucalyptus, or myrtle rust – caused by Puccinia psidii** – attacks plants in “only” one family – the Myrtaceae. Its host list now includes more than 450 species in 73 genera. More than 200 of these are native species in Australia – where more than 10% of the plant species are members of this family. At least some of these plants are highly vulnerable to the rust; more than half of the individuals of the small tree Rhodomyrtus psidioides surveyed in a recent study were dead less than four years after the pathogen was introduced (Carnegie et al. 2016). New Zealand also has large numbers of Myrtaceae.

Guava rust is believed to be native to South and Central America. It was introduced to the Caribbean and southern Florida by the first decades of the 20th Century. Recently, the pathogen began to move. A new strain arrived in Florida in the 1990s. The rust was detected in Hawai`i in 2005. There, it is killing the native endangered shrub Eugenia koolauensis and an invasive shrub Syzygium jambos. In the past decade, guava rust has also invaded Japan, China, Australia, South Africa and New Caledonia (Carnegie et al. 2016).

Laurel wilt** also attacks “only” one plant family, the Lauraceae. While the United States is home to a relatively small number of plants in this family, Central America is a center of endemism for the family. In the United States, concern has focused on the disease’s threat to the avocado industry. However, the pathogen’s principal wild host, redbay, is likely to be virtually eliminated from U.S. forests except as seedlings too small to be attacked. (One ray of hope: Professor Jason Smith at the University of Florida is making progress on breeding redbays resistant to the disease.) Given the large number of presumably vulnerable trees and shrubs in Mexico and Central America, the spread of laurel wilt into Texas is worrisome.

Other pathogens attack shrubs and trees across several families. I noted Phyotphthora cinnamomi above. Other Phytophthoras share this ability.

Phytophthora ramorum** has a host list exceeding 130 herbaceous, shrub, and tree species in families ranging from maples to rhododendrons, oaks to hemlocks. P. ramorum is established in coastal parts of California and southern Oregon; and in western United Kingdom and Ireland. Another Phytophthora, P. kernoviae,** has a similarly broad host range. It is also established in the United Kingdom.

Fusarium dieback is caused by the fungus Fusarium euwallacea, which is transported by two beetles in the Euwallacea genus, called the polyphagous** and Kushiro shot hole borers. The beetle is known to attack more than 300 species of trees, shrubs, and vines in more than 58 plant families; hosts include species of oaks, maples, sycamores, hollies, and willows.

These multi-host pathogens are extremely difficult to contain – or even to detect early in the invasion. Australia tried to contain Puccinia rust, but conceded failure after only a few months. USDA APHIS does not have containment programs for any of three pathogens described here – despite the danger they pose to trees and other native vegetation.

Industry groups sometimes fund efforts to protect their crops. Avocado growers have spurred research on both laurel wilt and the Fusarium fungus — threats to their crop. However, academic researchers working on the impacts of laurel wilt on native ecosystems must scramble for funds. This is exactly the kind of research that requires – and deserves – increased public funding.

What should be done? Phytosanitary agencies need to improve greatly programs aimed at preventing introduction of pathogens to naïve hosts in new geographies. For the U.S., APHIS has already advocated two important improvements:
1) Prohibiting temporarily plants suspected of transporting known damaging pathogens. This action is allowed under the NAPPRA (not authorized for importation pending pest risk assessment) program.
2) Requiring foreign suppliers of living plant imports to implement “hazard analysis and critical control point” programs to ensure that the plants are pest-free during production and transport. This approach is allowed under ISPM#36 and would be authorized under pending changes to APHIS’ “Q-37” regulation. [See Federal Register Vol. 78, No. 80 April 25, 2013]

(See longer discussions of these programs in Fading Forests III, available here.)

Unfortunately, implementation of both of these programs has stalled. A list of plants proposed in May 2013 for NAPPRA restrictions has still not been finalized. Revisions to the Q-37 regulation proposed in April 2013 have also not been finalized.

USDA leadership should promptly implement these long-delayed improvements.
** indicates those pathogens and insect/pathogen complexes that are described briefly here

Source

Posted by Faith Campbell

Help promote new film about tree-killing pests!

A new film demonstrating the impact of non-native tree-killing insects and diseases will be shown on or around Arbor Day (April 20). You can help ensure that lots of people see the film!!! Contact the program manager at your local PBS channel to ask that the channel broadcast the film.

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

“Trees in Trouble: Saving America’s Urban Forests” focuses on emerald ash borer in Cincinnati. The film explores our connections to the trees and forests in our communities – and the threats to those trees. The film’s website links viewers to resources for taking action.

To see clips from the film and other resources go to this site.

The film was produced by Torrice Media. Featured experts and speakers include Prof. Dan Herms of Ohio State, Jenny Gulcik, a community forestry consultant, and Cincinnati Council member Wendell Young.
As we all know, killer pests threaten trees across the country, not just in southern Ohio! Such pests are usually introduced first in cities – not necessarily ports! – because that is where crates and pallets, imported ornamental plants, and other articles to which pests attach arrive. Furthermore, trees along streets and in yards and parks are often more vulnerable than forest trees to such introduced pests because they are often subject to other stresses such as soil compaction, air pollution, elevated temperatures, and salt exposure. Finally, city trees are often planted as multiple individuals of the same species; when a pest that attacks that species arrives, entire neighborhoods can lose their tree canopy – and the real values that canopy provides.
Because of the high value of urban trees, these pests’ greatest economic damage is in urban and suburban areas. The study by Julianne Aukema and others documented that municipalities spend more than $2 billion annually to remove trees killed by non-native pests. Homeowners spend $1 billion a year removing trees killed by non-native pests, and another $1.5 billion is lost in property values due to tree mortality.

Thus, it is vitally important that American city dwellers learn about the values that trees provide to them, the threat to those values from introduced pests, and what they can do to minimize this threat. “Trees in Trouble” is a tool to advance citizens’ understanding of these issues through a combination of broadcasts, compelling video presentations and active civic engagement efforts linked to the film.

goldspotted oak borer

Some people – less familiar with the issue than we are – do not immediately understand the relevance of Cincinnati’s story to other cities. We know that while the trees and killers differ across the country, the cost to the communities is the same: destruction of trees that provide shade and other important ecosystem services and create our sense of home. Plus, the ways these pests are introduced are the same – and so are the steps we can take to reduce this threat.

[The goldspotted oak borer illustrates the universality of this threat – trees in southern California are being killed, too!]
You can help overcome this roadblock!
If you would like to help promote the film to your local PBS station or to local viewers, contact Andrea Torrice at 513-751-7050 or here

If you would like to obtain a copy of the film to screen to your group, contact Andrea Torrice at the same phone number or website. (Andrea is Italian; her name is pronounced “to re chay”, with the accent on “re”.)
Source:
Aukema, J. E., B. Leung, K. Kovacs, C. Chivers, K. O. Britton, J. Englin, S. J. Frankel, R. G. Haight, T. P. Holmes, A. M. Liebhold, D. G. McCullough, and B. Von Holle. 2011. Economic Impacts of Non-Native Forest Insects in the Continental United States. Plos One 6.

Posted by Faith Campbell