1. Minnesota First Detectors Thousand Cankers Disease (TCD) 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; in Tennessee (2010), Virginia, Pennsylvania (2011) Why is it important? Because as it spreads eastward, it threatens native eastern black walnut What are we doing? Prevention, early detection; management Declining black walnut Boulder, Colorado Oct. 2011 K.Kromroy

2. Minnesota First Detectors Thousand Cankers Disease: What is it? Two Juglans occur in Minnesota A disease of walnut trees (Juglans species)… www.plantcare.com/.../black-walnut-2127.aspx www.tree-pictures.com/butternut_tree_photos.html Eastern black walnut (Juglans nigra): Very susceptible Butternut (Juglans cinerea): Jan. 2012, Eugene OR - 1st report of natural infection

3. Minnesota First Detectors Walnut twig beetle (WTB) Pityophthorus juglandis Whitney Cranshaw, Colorado State University, Bugwood.org T unneling Entry / exit holes W. Cranshaw, Colorado State Univ. www.forestryimages.orgwww.forestryimages.org.... caused by a tiny insect that feeds and tunnels in the inner bark of the trunk and branches.

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

5. Minnesota First Detectors Ned Tisserat, Colorado State University Cankers grow together, eventually girdling and killing the branch or trunk

6. Minnesota First Detectors Whitney Cranshaw, Colorado State University Yellowing & wilting foliage, branch dieback; death in susceptible species K. Kromroy, MDA. Boulder, Colorado Oct. 2011

7. Minnesota First Detectors History of WTB and TCD Prior to 2003 Original description of WTB, New Mexico 1928Early 1990’s 2001 2003 Reports of black walnut decline & mortality in Oregon & Utah Report of black walnut mortality, northern New Mexico; WTB associated. Reports of black walnut decline & mortality in Boulder & Denver, Colorado

8. Minnesota First Detectors Thousand Cankers Disease: Where is it now? Original host: Arizona walnut 2010 2011 TCD is in all the red states

9. Minnesota First Detectors …because it threatens eastern black walnut in its native range & there is no control Why is it important?

10. Minnesota First Detectors 5.9 million Number of Black Walnut Trees > 1” dbh on Forestland

11. Minnesota First Detectors Black Walnut in Minnesota  5.9 million trees on forestland; Winona, Wabasha, Fillmore Counties > 1 million black walnut each  Annual state harvest is 1-2 million board feet; 4% of $75 million total stumpage value for all wood harvested  40+ mills in Minnesota use walnut; 12% imported (WI, IA) bark on  Almost 300,000 black walnut in urban areas (2010 MN DNR Rapid Assessment data).

12. Minnesota First Detectors Black Walnut Through Minnesota – hundreds of logs each year P. Ahlen, MDA

13. Minnesota First Detectors Ecologic Harder to measure Nuts as food for wildlife – squirrels, beavers, red-bellied woodpeckers Important species of riparian corridors Social Culture around walnuts for food Bark used for medicine, dye Other Values of Black Walnut

14. Minnesota First Detectors To our knowledge, TCD is still absent from Minnesota Choinski, 9/2011

15. Minnesota First Detectors PREVENTION Education Regulation Thousand Cankers Disease: What are we doing? EARLY DETECTION

16. Minnesota First Detectors Prevention: What are the pathways? PATHWAYESTIMATED APPROACH RATE Newton, L. & Fowler, G. 2009. Pathway Assessment: Geosmithia sp. and Pityophthorus juglandis Blackman movement from the western into the eastern United States. USDA APHIS Rev. 1:10.19.2009. 50 pgs. TimberLow; little timber shipped from west to east FirewoodLow - moderate; firewood distributors, long distance campers Wood packingLow to moderate Nursery stockLow; no reports of infested nursery plants Scion wood Low; programs in west revised to prevent spread Natural spreadLow; beetle flies 1-2 miles

17. Minnesota First Detectors ………..Wood for hobbyists ESTIMATED APPROACH RATE: ???? Internet sales; mail order companies; friends/acquaintances WTB spread from California to Pennsylvania http://www.furnituredesignidea.com/3729/cool-wooden- furniture-heartwood-design-furniture http://www.primocraft.com/Bar- Features/Walnut-Burl-Inlay.html

18. Minnesota First Detectors http://www.woodweb.com/cgibin/ forums/vawp.pl?read=531138 Black walnut logs, slabs, burls with bark attached. T. Seeland, MDA. Davis, Nov. 2011

19. Minnesota First Detectors  Newsletters, websites  Telephone, email, visits  Presentations TO  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 Education

20. Minnesota First Detectors Regulation Who regulates? Infested western states - No APHIS - No Eastern states - Yes

21. Minnesota First Detectors Thousand Cankers Disease: Regulation Thousand cankers disease occurs Black walnut native range Exterior quarantine, terms vary by state Interior quarantine, by county 2 counties added

22. Minnesota First Detectors Early Detection 2011 More than 2500 walnut trees visually assessed in urban, rural and industrial communities 5 suspect trees sampled and examined in lab NO TCD 2012 Visual assessment of walnut trees at or near mills that use walnut Traps with walnut twig beetle lure hung at 2 sites Data analyses in progress 2013 Farm bill funding for TCD surveys in MN and 16 other states MN will hang traps at 10 high risk sites Continue visual assessment

23. Minnesota First Detectors Lure Early Detection: It’s here – a trap with a lure! S.Seybold, USFS

24. Minnesota First Detectors Visual Assessment: Early symptoms  Thinning crown  Yellow or wilting leaves  Tree may be infested 7 or more years before see crown symptoms J.Juzwik, USFS

25. Minnesota First Detectors Early symptoms  Wilting leaves  Attached brown leaves  Small leaves J.Juzwik, USFS

26. Minnesota First Detectors Photo by T. Seeland, MDA, Denver, Colorado, June 2011 Oozing canker on Juglans nigra

27. Minnesota First Detectors Actively declining symptoms – rapid wilting Branch cankers below wilting foliage J.Juzwik, USFS

28. Minnesota First Detectors Top down dieback B.Moltzan, USFS

29. Minnesota First Detectors Many tiny holes on branches >1.5 inches W. Cranshaw, Colorado State Univ. www.forestryimages.orgwww.forestryimages.org

30. Minnesota First Detectors Galleries and meandering tunnels Whitney Cranshaw, Colorado State University, Bugwood.org

31. Minnesota First Detectors Small cankers in inner bark J.Juzwik, USFS

32. Minnesota First Detectors Old cankers under bark on Juglans nigra lose their color Photo by T. Seeland, MDA, Denver CO June 2011

33. Minnesota First Detectors Large dead areas on branches & stems J.Juzwik, USFS

34. Minnesota First Detectors What else might be mistaken for TCD? AnthracnoseFusarium canker Joseph O'Brien, USDA Forest Service, Bugwood.org J.Juzwik, USFS

35. Minnesota First Detectors Unknown What else might be mistaken for TCD? Site stress Photo by Choinski, 9/2011 J.Juzwik, USFS

36. Minnesota First Detectors Other insects and their damage Asian ambrosia beetle Xyleborinus saxeseni Insects found on girdled black walnut in Indiana & Missouri:  Ambrosia beetles – 7 species  Weevils – 5 types  Bark beetles – 2 species 80% of beetles in MO Natasha Wright, Florida Department of Agriculture and Consumer Services, Bugwood.org

37. Minnesota First Detectors Cossoninae weevil Himatium errans Weevil holes Weevil tunnels? On walnut log, St. Paul rail yard 2011 Photos by J.Juzwik, USFS

38. Minnesota First Detectors  Tree removal  Proper disposal  Bury  Burn Sanitation Management Disposal site in Boulder, Colorado October 2011, K.Kromroy, MDA

39. Minnesota First Detectors  Treatments for wood: Heat, debarking, fumigation  Treatments for trees: Insecticides  Insects  WTB genetics, behavior, cold tolerance  Other insects that may vector pathogen  Fungi  Genetics, aggressiveness  Other canker fungi  Variation in susceptibility/resistance of the host  Role of stress in WTB attraction and in canker development  Time-line of disease progression Studies in progress – preliminary results Management

40. Minnesota First Detectors Acknowledgements  Jenny Juzwik, Paul Castillo - USFS Northern Research Station.  Keith Jacobsen, Don Deckard, Lance Sorenson -MN DNR.  Mike Greenheck - Gorman Creek Farms, Kellogg MN.  Angie Gupta - UM Extension.  Tina Seeland, Bob Koch, Mark Abrahamson - MDA