Current California Oak Mortality Task Force Newsletter
MAY 2013 REPORT
(Printable May 2013 COMTF Report)
Monitoring
Texas cooperators in the National Phytophthora ramorum Early Detection Survey of Forests identified a new positive waterway outside a Houston nursery after detecting the pathogen from baits deployed in February. This was the first new positive site of the 2013 survey year and the second new site in the Houston area in the past three months. A second, separate positive was also obtained in February from a site first identified positive in December 2012. While there is currently no evidence suggesting recent P. ramorum introductions, both nurseries had received suspect positive plants in the past. All three positives were obtained from leaf baits deployed in waterways. Cooperators are now repeating the survey with a water sampling technique called “bottle of bait.”
The 2013 National P. ramorum Early Detection Survey of Forests is underway with an estimated 68 streams to be assayed in 12 states nationwide, down from 17 states participating in 2012 due to budget shortfalls. The survey focuses on high-risk waterways near infested forest areas in CA and OR; positive waterways already detected in AL, FL, GA, MS, NC, TX, and WA; and high-risk waterways outside nurseries that may have received infected ornamental plants in these states, plus NY and PA.
SODMAP mobile is a new app available for free at the Apple App Store. Developed by the UC Berkeley Forest Pathology and Mycology Lab, the app is intended for field use and allows the user to identify the locations of trees sampled for P. ramorum and determine the health of each tree at the time of sampling. The app also can calculate the risk of infection at the location where the user is by using the number of sampled trees in the area and proximity of positive trees. High- or moderate-risk ratings indicate action may be needed to preventively protect oak trees. This tool can assist in helping property owners and managers as well as tree care professionals make management decisions; however, other factors must be taken into consideration, such as host distribution, weather patterns, and land management goals. Funding for development of the app was provided by the Gordon and Betty Moore Foundation.
Nurseries
A Gilroy nursery (Santa Clara County) was confirmed positive for P. ramorum on April 18th. The positive Loropetalum chinense (5 g) plant was identified during a compliance agreement inspection. No high-risk host and associated host plants have been shipped interstate in the last six months. This facility was previously positive in 2004 and 2005. The Confirmed Nursery Protocol has been implemented.
Oregon had three P. ramorum-positive nurseries identified in April. A Clackamas County facility was found to have infected Camellia, Gaultheria, Pieris, Rhododendron, Trachelospermum, and Viburnum on April 11th. Soil sample tests are still pending. The nursery has not previously tested positive. Two Washington County nurseries were also found with P. ramorum-positive plants on April 16th. Both nurseries have been previously positive, with the first nursery positive annually from 2006 through 2010 and the second positive in 2012. Positive plants at the first nursery included Rhododendron sp. and Magnolia grandiflora. Positive plants at the second nursery included Rhododendron ‘Anna Kruschke’ and Viburnum ‘Pink Dawn.’ Soil sample testing at both nurseries is in process.
The Kitsap County, Washington retail garden center found positive in March (reported in April newsletter) had a positive soil sample confirmed at the nursery on April 11th. The nursery has followed USDA direction for treating the affected area, and the retail Confirmed Nursery Protocol is nearly complete.
The Washington Department of Agriculture has conducted recertification sampling at 22 interstate host shipping nurseries this spring, with no P. ramorum-positive samples identified.
Research
Kelsey, R.G.; Beh, M.M.; Shaw, D.C.; and Manter, D.K. 2013. Ethanol Attracts Scolytid Beetles to Phytophthora ramorum Cankers on Coast Live Oak. Journal of Chemical Ecology. 39: 494-506.
Ethanol in sapwood was analyzed along vertical transects, through small spot cankers and larger basal cankers, of Phytophthora ramorum-infected stems of Quercus agrifolia at three sites in California. Trees with large basal cankers, known to attract scolytid beetles, had a 4.3 times higher ethanol level than trees with spot cankers that attract fewer beetles. Ethanol concentrations inside cankers, where scolytid beetles preferentially attack, varied by about four orders of magnitude among samples, with a median level of 16.0 μg.g−1 fresh mass. This concentration was 4.3 and 15.5 times greater, respectively, than the concentrations at 1 cm or 15–30 cm outside the canker boundaries. In the laboratory, we demonstrated that ethanol escaped through the bark of a Q. garryana log just 3 days after it was added to the sapwood. At the three study sites, traps baited with ethanol captured more Xyleborinus saxesenii, Pseudopityophthorus pubipennis, and Monarthrum dentiger (all Coleoptera: Curculionidae: Scolytinae) than traps baited with ethanol plus (−)-α-pinene, or ethanol plus 4-allylanisole (4AA). Logs of Q. agrifolia with a 50 % ethanol solution added to the sapwood were placed at the study sites, with or without additional bark treatments above the ethanol. The number of scolytid beetle gallery holes above the ethanol-infused sapwood was 4.4 times greater than that on the opposite side of the log where no ethanol was added. Attachment of ultra-high release (−)-α-pinene pouches to the bark surface above the 50 % ethanol solution reduced scolytid attacks to a density of 19.1 % that of logs without this treatment. We conclude that ethanol in P. ramorum cankers functions as a primary host attractant for scolytid beetles and is an important link in colonization of these cankers and accelerated mortality of Q. agrifolia. The results of this research shed light on the chemical ecology behind the focused scolytid attacks on P. ramorum-infected coast live oaks, and lay the groundwork for future efforts to prolong the survival of individual trees of this keystone species.
Purse, B.V.; Graeser, P.; Searle, K.; Edwards, C.; and Harris, C. 2013. Challenges in Predicting Invasive Reservoir Hosts of Emerging Pathogens: Mapping Rhododendron ponticum as a Foliar Host for Phytophthora ramorum and Phytophthora kernoviae in the UK. Biological Invasions. 15:529–545.
Invasive species can increase the susceptibility of ecosystems to disease by acting as reservoir hosts for pathogens. Invasive hosts are often sparsely recorded and not in equilibrium, so predicting their spatial distributions and overlap with other hosts is problematic. We applied newly developed methods for modeling the distribution of invasive species to the invasive shrub Rhododendron ponticum—a foliar reservoir host for the Phytophthora oomycete plant pathogens, P. ramorum and P. kernoviae, that threaten woodland and heathland habitat in Scotland. We compiled eleven datasets of biological records for R. ponticum (1,691 points, 8,455 polygons) and developed Maximum Entropy (MaxEnt) models incorporating landscape, soil, and climate predictors. Our models produced accurate predictions of current suitable R. ponticum habitat (training AUC = 0.838; test AUC = 0.838) that corresponded well with population performance (areal cover). Continuous broadleaved woodland cover, low elevation (\400 m a.s.l.) and intermediate levels of soil moisture (or Enhanced Vegetation Index) favored presence of R. ponticum. The high coincidence of suitable habitat with both core native woodlands (54 % of woodlands) and plantations of another sporulation host, Larix kaempferi (64 % of plantations) suggests a high potential for spread of Phytophthora infection to woodland mediated by R. ponticum. Incorporating non-equilibrium modeling methods did not improve habitat suitability predictions of this invasive host, possibly because, as a longstanding invader, R. ponticum has filled more of its available habitat at this national scale than previously suspected.
Related Research
Leonberger, A.J.; Speers, C.; Ruhl, G.; Creswell, T.; and Beckerman, J.L. 2013. A Survey of Phytophthora spp. in Midwest Nurseries, Greenhouses, and Landscapes. Plant Disease. 97(5): 635-640.
Education and Outreach
Eleven Spring 2013 SOD Blitz Opportunities Left – Community members living near areas known to be impacted by SOD are encouraged to attend a SOD Blitz and learn how to look for the disease so that they can monitor for it in their community, facilitating early detection of new outbreaks. Participants will be trained to identify and collect symptomatic bay leaves and record sample locations. Samples will be taken to the Garbelotto lab at UC Berkeley to test for the pathogen. Follow-up local sessions in the fall will present the mapped outcomes of the blitzes. Attendees will learn how to correctly use the distribution maps, determine risk of infection for their oaks and tanoaks, and learn science-based recommendations to help prevent and manage SOD. For details on Blitz locations and further information, see the “Calendar of Events” below.
Resources
The “Sudden Oak Death and Phytophthora ramorum 2011 – 2012 Summary Report, A Compendium of 2012 Monthly Newsletters” is now available on the Task Force website at http://www.suddenoakdeath.org/wp-content/uploads/2013/04/2012-Newsletter-Summary-Report.pdf.
Elliott, M. and Chastagner, G.A. 2013. Susceptibility of Rhododendrons to P. ramorum. B&B 65(3): 14-17. Available online at http://www.bluetoad.com/publication/?i=154930.
SODMAP has been updated to includes an additional 2,151 data points, including 2012 SOD Blitz results as well as new information from California researchers. To access the updated map in Google Earth, go to www.sodmap.com.
“Trade in forest commodities and the role of phytosanitary measures,” a free online training course, is now available from the Food and Agriculture Organization of the United Nations and the International Plant Protection Convention Secretariat. The course provides a checklist to help producers comply with phytosanitary requirements in international markets as well as a review of the most common pests. To access the course, go to http://www.fao.org/forestry/foresthealthguide/82418/en/.
Personnel
Dan Stark has been hired as the new SOD Project Coordinator for UCCE Humboldt and Del Norte Counties. In his new role, Dan will monitor for SOD across public, private, and tribal lands; explore and implement best-available management practices for the control of SOD; and encourage a multi-stakeholder dialogue and participation in the SOD program through outreach and educational opportunities.
Dan received his M.S. from UC Berkeley in May 2012 from the Division of Ecosystem Science in the Department of Environmental Science, Policy, and Management. He has worked extensively on projects pertaining to pathogen, insect, and tree relations, such as insect vectors of pitch canker and the progression of Sudden Oak Death in long-term ecological study plots. Dan can be reached at (707) 445-7351 or stark@ucdavis.edu.
Jack Marshall retired from the California Department of Forestry and Fire Protection (CAL FIRE) as a Forest Pest Specialist on May 1st. Jack covered forest health for California’s northern and central coast and served on the front line of early detection and response to P. ramorum in Mendocino, Humboldt, and other counties. We wish Jack a long and happy retirement! He will be missed.
Calendar of Events
5/11 – Mendocino SOD Blitz; College of the Redwoods; 1211 Del Mar Drive; Fort Bragg; 10:00 a.m. – noon; For more information, contact Lori Hubbard at lorih@mcn.org.
5/13 – 5/17 – 7th Annual Western Hazard Tree Workshop; Relics Restaurant and Conference Center, Sedona, Arizona. The workshop features indoor discussions and outdoor field trips highlighting “state of the art” hazard tree science and management. The workshop will also feature presentations and demonstrations by Dr. Frank Rinn, inventor of the resistance drill and developer of much of the software used in sonic tomography (Rinntech Tree Inspection Technology, Heidelberg, Germany). Agenda, lodging, registration and other workshop details are at http://www.fs.fed.us/foresthealth/technology/htwc/index.htm. For more information, contact Pete Angwin at (530) 226-2436 or pangwin@fs.fed.us.
5/14 – Best Management Practices Programs for CA Nurseries: Review and Outlook Training Session; UC Cooperative Extension Monterey County; 1432 Abbott Street; Salinas, CA 93901; For more information, go to http://ucanr.edu/sites/UCNFA/2013_Educational_Programs/BMPs_Workshop_Salinas/.
5/18 – South Bay SOD Blitz, Option 1; Montalvo, Location to be determined; 10:00 a.m. to noon; For more information, contact Kelly Sicat at KSicat@montalvoarts.org. or Arvind Kumar at arvind.kumar@cnps.org.
5/18 – South Bay SOD Blitz, Option 2; South Skyline, Location to be determined; 1:00 – 3:00 p.m.; For more information, contact Jane Manning at skyline_sod@yahoo.com.
5/18 – Protect the Value of Your Forest: A Workshop for Forest Landowners; Mendocino County UCCE office; 890 N. Bush Street; Ukiah; 9:30 a.m. – 3:00 p.m.; Registration is $25 and is available online at http://ucce.ucdavis.edu/survey/survey.cfm?surveynumber=10294. For more information, go to http://ucanr.edu/sites/forestry/Events/?calendar=yes&g=28858 or contact Rick Standiford at standifo@berkeley.edu.
5/25 – Penninsula SOD Blitz, Option 1; Burlingame Hills; 120 Tiptoe Lane (off Canyon Rd.); Burlingame; 10:00 a.m. – noon; For more information, contact Steve Epstein at steve@burlingamehills.org.
5/25 – Penninsula SOD Blitz, Option 2; Woodside/Portola Valley/Emerald Hills; Woodside Town Hall; 2955 Woodside Road; Woodside; 1:00 – 3:00 p.m.; For more information, contact Debbie Mendelson at sodblitz@gmail.com.
5/29 – Protect the Value of Your Forest: A Workshop for Forest Landowners; The McConnell Foundation; 800 Shasta View Drive; Redding; Ukiah; 9:30 a.m. – 3:00 p.m.; Registration is $25 and can be done online at http://ucce.ucdavis.edu/survey/survey.cfm?surveynumber=10294. For more information, go to http://ucanr.edu/sites/forestry/Events/?calendar=yes&g=28858 or contact Rick Standiford at standifo@berkeley.edu.
6/1 – Atherton SOD Blitz; Carriage House; Holbrook Palmer Park; 150 Watkins Ave.; Atherton; 10:00 a.m. – noon; For more information, contact Susan Finocchio at susanfin@earthlink.net.
6/8 – Los Altos Hills SOD Blitz; Los Altos Hills Town Hall; 26379 Fremont Rd.; Los Altos Hills; 10:00 a.m. to noon; For more information, contact Sue Welch at sodblitz09@earthlink.net.
6/15 – Sonoma SOD Blitz, Option 1 – Santa Rosa; Location to be determined; 10:00 a.m. – noon; For more information, contact Phyllis Turrill at rainbow3@comcast.net.
6/15 – Sonoma SOD Blitz, Option 2; Sonoma Community Center; 276 East Napa Street; Sonoma; 10:00 a.m. – noon; For more information, contact Phyllis Turrill at rainbow3@comcast.net.
6/15 – Sonoma SOD Blitz, Option 3; Sebastopol; Location to be determined; 10:00 a.m. – noon; For more information, contact Phyllis Turrill at rainbow3@comcast.net.
6/15 – Napa SOD Blitz; UC Cooperative Extension Office, 1710 Soscol Avenue, Napa; Time to be determined; For more information, contact Bill Pramuk at info@billpramuk.com or Henni and Gerrald Cohen at hennic1044@gmail.com.
6/15 – Protect the Value of Your Forest: A Workshop for Forest Landowners; UC Berkeley Campus; 159 Mulford Hall at Oxford Ave. and University Ave.; Berkeley; 9:30 a.m. – 3:00 p.m.; Registration is $25 and is available online at http://ucce.ucdavis.edu/survey/survey.cfm?surveynumber=10294. For more information, go to http://ucanr.edu/sites/forestry/Events/?calendar=yes&g=28858 or contact Rick Standiford at standifo@berkeley.edu.
6/22 – Protect the Value of Your Forest: A Workshop for Forest Landowners; Placer County UCCE office, DeWitt Center, Room 306; 11477 E Avenue; Auburn; 9:30 a.m. – 3:00 p.m.; Registration is $25 and is available online at http://ucce.ucdavis.edu/survey/survey.cfm?surveynumber=10294. For more information, go to http://ucanr.edu/sites/forestry/Events/?calendar=yes&g=28858 or contact Rick Standiford at standifo@berkeley.edu.
8/24 -25 – 5th Phytophthora, Pythium, and Related Genera Workshop; Beijing, China; The first day focuses on the methodology for studying Oomycetes (particularly Phytophthora and Pythium species), while the second day will cover contemporary research topics. For abstract submission, registration, and workshop information, go to http://www.icppbj2013.org/file/workshop/5thInternationalWorkshop.asp.
9/4 – SOD Treatment Workshop: meet at oak outside of Tolman Hall, UC Berkeley Campus; 1:00 – 3:00 p.m.; Pre-registration is required. This class is free and will be held rain or shine. To register, or for questions, email kpalmieri@berkely.edu, and provide your name, phone number, affiliation and license number (if applicable), and the date for which you are registering. For more information, go to http://nature.berkeley.edu/garbelotto/english/sodtreatmenttraining.php.
10/2 – SOD Treatment Workshop: meet at oak outside of Tolman Hall, UC Berkeley Campus; 1:00 – 3:00 p.m.; Pre-registration is required. For more information, see the 9/4 listing above.
10/23 – SOD Treatment Workshop: meet at oak outside of Tolman Hall, UC Berkeley Campus; 1:00 – 3:00 p.m.; Pre-registration is required. For more information, see the 9/4 listing above.
11/13 – SOD Treatment Workshop: meet at oak outside of Tolman Hall, UC Berkeley Campus; 1:00 – 3:00 p.m.; Pre-registration is required. For more information, see the 9/4 listing above.
Symptom Gallery
