Thousand Cankers Disease

1. Thousand Cankers Disease • What is it? • Where is it? • Why do we care? • What should we be do about it now? Kathleen Alexander, Boulder, CO

2. Thousand Cankers Disease • What is it? A disease of some walnut trees that is caused by an insect and a fungus • Where is it? In western and southwestern areas of the United States • Why do we care? Because if it spreads eastward, it may threaten native eastern black walnut in several states • What should we do about it now? Be aware - recently discovered, still many unanswered questions

3. Thousand Cankers Disease: What is it? A disease of some walnut trees (Juglans species) • Two occur in Minnesota – J. cinerea, J. nigra

4. Thousand Cankers Disease: What is it? • ….. caused by a tiny insect that feeds and tunnels in the inner bark of the trunk and branches Walnut twig beetle Pityophthorus juglandis Tunneling Entry / exit holes Whitney Cranshaw, Colorado State University, Bugwood.org W. Cranshaw , Colorado State Univ. www.forestryimages.org

5. Thousand Cankers Disease: What is it? • The walnut twig beetle introduces a fungus - Geosmithia morbida • that kills the bark and phloem, causing a canker Jim LaBonte, OR Dept. Agric. Whitney Cranshaw, Colorado State University, Bugwood.org “Canker: A visible dead area, usually of limited extent, in the cortex or bark of a plant.” (Tainter & Baker, 1996) Ned Tisserat, Colorado State University

6. Thousand Cankers Disease: What is it? • Cankers coalesce, eventually girdling and killing the branch or trunk Ned Tisserat, Colorado State University

7. Thousand Cankers Disease: What is it? • Yellowing & wilting foliage, followed by branch dieback & death may occur in susceptible species Kathleen Alexander , City Forester, Boulder, CO Whitney Cranshaw, Colorado State University

8. Thousand Cankers Disease: Where is it? States in red & Tennessee Confirmed July 2010 Original host, Arizona walnut Juglans major

9. Thousand Cankers Disease: Where is it? KY MO • Black walnut dieback for 2+ years. • TCD confirmed July 2010. • TCD confirmed in 4 counties. • Surveys initiated in neighboring states. VA NC 1st report in native range Knoxville, TN Source: M. Mielke NCFPW 2010 MS AL GA Urban settings news.tennesseeanytime.org/node/5926

10. Thousand Cankers Disease: Why do we care? …because it threatens eastern black walnut in its native range & there is no control

11. Thousand Cankers Disease: Why do we care? 5.9 million

12. Thousand Cankers Disease: Why do we care? Impacts on wood products industries • United States • 1.9% total hardwoods available commercially • net volume growing stock valued at > $500 billion • exports to 67 countries • annual average value of export is $325 million • Minnesota • 1-2 million board feet harvested annually • 0.1% of volume of all wood harvested • $3 million = 5% of $60 million total stumpage value for all wood harvested

13. Thousand Cankers Disease: Why do we care? Other impacts • Ecologic • Harder to measure • Nuts as food for wildlife – squirrels, beavers, red-bellied woodpeckers • Important species of riparian corridors • Bark used for medicine, dye • Social • Culture around walnuts for food

14. Thousand Cankers Disease: What should we do? National Response Framework for Thousand Cankers Disease (TCD) on Walnut To coordinate response among government, non-government & private stakeholders Prepared by: TCD-Technical Working Group

15. Thousand Cankers Disease: What should we do? PREVENTION Minimize introduction risk potential pathways?

16. Thousand Cankers Disease: What should we do? Tools for prevention • Regulation • Outreach • Early detection

17. Thousand Cankers Disease: What should we do? Regulation • Who regulates? • Infested western states? No • APHIS? • Not at this time • Eastern states? • Yes

18. Thousand Cankers Disease: Regulation State Quarantines Exterior quarantines Exterior quarantines ? Interior quarantine Source: E.Borchardt, MN Dept. Agric.

19. Thousand Cankers Disease: What should we do? Outreach • Newsletter articles, websites • Telephone, email, visits • Presentations • First Detector network • Partner organizations • Mill owners • Loggers • Landowners • Tree care companies • Nurseries Photos courtesy of Mike Greenheck, Forest Field Day , Gorman Creek Farm, Kellogg, MN, October 2010

20. Thousand Cankers Disease: What should we do? Early Detection • TCD tree takedown workshops • First detector training • Visual surveys & sampling from suspect trees • Site solicitation efforts

21. Early Detection: Does your black walnut have TCD? • Early symptoms (late June to late August) Area of thinning crown Yellow or wilting leaves Leaves smaller than healthy leaves Attached brown leaves

22. Early Detection: Does your black walnut have TCD? • Actively declining crown symptoms Limbs die in 1 season Rapid wilting Cankers on branch below wilting foliage Little live crown on trees affected previous season

23. Early Detection: Does your black walnut have TCD? • Late symptoms • Many tiny holes on branches >1.5 inches • Galleries and meandering tunnels • Small cankers in inner bark if scrape away outer bark • Large dead areas on branches & stems

24. Early Detection: Does your black walnut have TCD? • What else may be confused with Thousand Cankers Disease? Anthracnose • Nectria cankers Fusarium cankers -similar decline • Other beetles Hail injury, storm damage • Squirrel girdling of branches

25. Thousand Cankers Disease: What should we do? Targeted survey for thousand cankers disease of walnut in Minnesota: USDA Forest Service Northern Research Station and the Minnesota Department of Agriculture • POTENTIAL TREES FOR 2010 THOUSAND CANKERS DISEASE TARGETED SURVEY • (Minnesota) • Dieback in Black Walnut Observed between mid-June and late August 2010 • Please return by mail, email or fax to one of the following locations: • Jennifer Juzwik / Mike Ostry/Paul Castillo Kathy Kromroy • USDA Forest Service, 1561 Lindig St. Minnesota Dept. of Agric., Plant Protection Division • St. Paul, MN 55108 625 Robert Street North, St. Paul, MN 55155-2538 • E-mail: jjuzwik@fs.fed.us or mostry@fs.fed.usKathryn.Kromroy@state.mn.us • Facsimile: (651) 649-5040 Facsimile: (651) 201-6108 • Telephone: (651) 649-5114 (JJ) and (651) 649-5113 (MO) Telephone: (651) 201-6343 • OR • Please enter information on-line using the US Forest Service, NA S&PF “survey monkey” at: http://www.surveymonkey.com/s/thousandcankers • SUBMITTER’s CONTACT INFORMATION:Date of submission: • LANDOWNER OR LAND MANAGER INFORMATION: JUGLANDACEAE INFORMATION: Please fill in the section with as much information as you have DESCRIPTION OF THE SITUATION

26. Acknowledgements • Jenny Juzwik, Mike Ostry, Paul Castillo. USFS Northern Research Station • Manfred Mielke. USFS State & Private Forestry • Keith Jacobsen, Lance Sorenson, Don Deckard, MN DNR • Mike Greenheck, grower, Gorman Creek Farms, Kellogg MN • Mel Baughman, Angie Gupta, UM Extension