Columbian Timber Beetle or is it … Beech Timber Beetle?

1. Columbian Timber Beetleor is it …Beech Timber Beetle? Linda WilliamsWI DNR Forest Health SpecialistNortheast Region March 2011

2. The problem • First visited a site in 2008 • Silver maple swamp • Insect samples identified as Columbian Timber Beetle (Corthylus columbianus) • Significant staining in silver maple • Significant degrade due to staining but no decline or mortality • More recently additional reports, same symptoms • Reducing value “from No.1 log to pallet material”

3. Columbian Timber Beetle • Native beetle, ambrosia beetle • Infested trees appear healthy • Not noticeably affected even after repeated attacks • Hosts • Many maples, many oaks, beech, box elder, yellow birch, basswood • Study by McManus and Giese (1968) showed precipitation, temperature, and flooding, were positively related to population fluctuations of the Columbian timber beetle in red and silver maple in Indiana • No previous outbreaks had been reported in Wisconsin in maple

4. The problem • Stand was being removed from a program and a termination tax would need to be paid based on the value of the timber • We worked with the WI DNR Tax Law section to pilot the process • Most Catastrophic Loss is from known events and is determined at the time of harvest • These trees were not going to be harvested and this damage does not appear to kill these trees

5. Photo by Linda Williams June 22, 2010 • Site conditions were NOT dry (this was a shallow spot where this photo was taken

6. Photo by Linda Williams • Exit/entrance holes • No bleeding on maples • Extensive staining inside • Frass toothpicks short or non-existent

7. Photo by Linda Williams • Dramatic staining up and down from the galleries

8. Photos by Linda Williams How to determine damage level • Coring trees to look for staining • Staining showed clearly but you wouldn’t know what staining was from

9. Photo by Linda Williams • Drawbar & knife • Staining did not show up just under the bark

10. Photo by Linda Williams • Peeled bark shows holes but no staining

11. Photo by Linda Williams • Cutting down a small tree (6”+) to look at the cross section AND a horizontal cut is the best way to determine presence

12. Photo by Linda Williams • Staining pattern clearly evident

13. Photo by Linda Williams • Damage occurs in all sizes of trees • Small holes are easier to spot on smooth barked trees

14. Photo by Linda Williams • Adult beetle (near the 3cm mark) • Beetles collected & sent to Phil Pellitteri for ID

15. Columbian Timber Beetle Guide to Insect Borers of North American Broadleaf Trees and Shrubs

16. Beech Timber Beetle Beetles attack low vigor trees and are most injurious to the green wood of diseased, injured, and dying trees. They also infest recently cut logs and green stumps. Most attacks on standing trees occur within the basal 2.1m of the bole, none are found above 6.1m. -from Guide to Insect Borers in North American Broadleaf Trees and Shrubs

17. Beech Timber Beetle Columbian Timber Beetle

18. Beech Timber Beetle • From USFS Research Note NE-49 on birch

19. Results • Identification of specimens from 2008 • Columbian timber beetle (Corthylus columbianus) • Identification of specimens from 2010 • Beech timber beetle (Xyloterinus politus) • Site was determined to qualify for Catastrophic Loss • Other sites in the area that are suspected to be infested can be evaluated by cutting down a small tree, taking a cross section, and a horizontal section • Confounding factors • Attacked trees appear vigorous, healthy, no mortality • Staining extensive, not just in outer growth rings • Frass toothpicks minimum to non-existent • Attacks extend into branches

20. Photos by Linda Williams More to come: • Plan to sample again spring 2011 • Will monitor sites for decline • Would like to host a field day for foresters in area to see the damage