Emerald Ash Borer Homeowner Management Options

2. Ash Tree Identification
(Fraxinus sp.)
 Ash (Fraxinus)
 Maples (Acer)
 Horse chestnut (Aesculus)
 Shrubs: Viburnum, Forsythia
etc.
 Hickories (Carya)
 Oaks (Quercus)
 Beech (Fagus)
 Tuliptree (Liriodendron)
 Sweet Gum (Liquidambar)

3. Ash Tree Identification
 Compound leaf
 Fruit is single winged
samara
www.bugwood.org (Paul Wray, Michigan Dept. of Agriculture)

4. Ash Tree Identification
 Diamond patterned bark
 Opposite branches
 Stubby, blunt twigs
www.bugwood.org (Keith Kanoti)

5. Emerald Ash Borer (EAB)
 Invasive wood-boring
beetle introduced from
China/East Asia
 Feeds on ash trees
 Discovered in
Michigan in 2002
 Found in Virginia in
2003 and again in
2008
www.forestryimages.org (Linda Bauer, Debbie Miller)

6. www.emeraldashborer.info (United States Department of Agriculture)

7. Signs
 Larvae burrow into
bark and feed on
vascular tissue
 Leave winding
“galleries” where
they have burrowed
 Adults emerge
through “D”
shaped exit holes
www.forestryimages.org (Pennsylvania Department of Conservation and Natural Resources , David. R. McKay,
David Cappaert)

8. Symptoms
 Canopy dieback/thinning crown
 Epicormic sprouting
 Growth from a previously dormant bud on
the trunk or a limb of a tree
 Woodpecker activity
 Bark splits

9. Canopy Dieback/Epicormics
www.forestryimages.org (Linda Bauer, Daniel Herms)

10. Bark Splits/Woodpecker Activity
www.forestryimages.org (Michigan Dept. of Agriculture)

11. EAB Invasion Wave
http://extension.entm.purdue.edu/treecomputer/index.php?page=concepts/invasionWave.php&section=2
Fairfax County

12. www.goodtreecare.com

13. Management Options for Ash
Trees
1. Remove ash trees that are unsafe as they
die
2. Replace ash trees that were removed
3. Treat the remaining healthy ash trees
Data was prepared using the Emerald Ash Borer Cost Calculator developed at Purdue University,
http://extension.entm.purdue.edu/treecomputer/index.php

14. Tree Removal
 High initial investment
 Loss of tree benefits/ecosystem services
(http://www.itreetools.org/design.php)
○ Stormwater runoff prevention
○ Shade (reduction of energy use)
○ Aesthetics
 Deeds or HOA covenants may require
special exceptions or permission to remove
a tree
○ These requirements will be listed in the property
development plan

15. Ash Removal
Photos courtesy: Rob Gorden, Arborjet Inc.

16. Tree Replacement
 Replace dead ash trees with other
native tree species
 http://www.fairfaxcounty.gov/dpwes/navb
ar/faqs/treecare.htm
 Plant a variety of different species
 Diversity is a proactive approach to insects
or diseases that may emerge in the future

17. Ash Replacement

18. EAB Management Options
 Pesticide Treatment
 Cost is dispersed over many years
 Can lessen pesticide application intensity after
beetle population decreases
 Option to treat the ash tree so that it will
eventually be replaced with another species
without the loss of ecosystem services

19. Ash Protection/Treatment

20. Available from www.emeraldashborer.info
http://www.emeraldashborer.info/documents/Multistate_EAB_Insecticide_F
act_Sheet.pdf

21. Pesticide Treatment Timing
 Trees must be actively respiring (must
have leaves)
 Kill larvae under the bark of the tree
 Kill female adults before eggs are
produced
 Female adults have to
feed on foliage for two
weeks before they
produce and lay eggs

22. 15% of crown is dead

23. Treatable Ash Tree
Photo courtesy of: Donna Brok http://gardenwalkgardentalk.com/2014/07/01/emerald-ash-borer-a-first-hand-look/
40% of crown is dead

24. Untreatable Ash Tree
Photo: Eric R. Day, www.bugwood.org
>50% of crown is dead

25. EAB Homeowner Treatment
 Must be applied every year in mid-
Spring
 Not effective for trees >20-25”
 Dinotefuran requires more product for
trees >15”
Insecticide Description
Application
Method
Dinotefuran Granular Soil
Imidacloprid
2x
Soil drench
Soil*
*Can’t apply near
water sources or
streams

26. EAB Professional Treatment
Insecticide
Application
Method
Advantage Disadvantage
Dinotefuran
Bark spray, soil
injection
Very water
soluble
Less effective at
high EAB density
Can apply later
in the year
Need higher dose
for large trees
Imidacloprid
2x
Soil drench,
trunk injection
Inexpensive
Less effective at
high EAB density
Readily
available
Takes 4-6 weeks to
take effect
Emamectin
Benzoate
(TreeAge)
Trunk injection
Very good
control at all
EAB infestation
stages
Expensive
Azadirachtin
(TreeAzin)
Trunk injection
Certified for
Organic use
Expensive;
Only reduces
fecundity of adults

27. Pesticide Injection (Tree-äge)

28. Example Scenario
 50 ash trees along street
 Majority of trees approximately 12-18”
diameter
 Various stages of EAB infestation
 Thin foliage
 Dead branches
 Canopy dieback

29. Example Scenario Costs
Data was prepared using the Emerald Ash Borer Cost Calculator developed at Purdue University,
http://extension.entm.purdue.edu/treecomputer/index.php
Treatment Initial Cost Year 4
25 year
cumulative
Removal $1,361 $26,958 $29,643
Replacement $2,870 $43,360 $48,079
Pesticide
Treatment
(Tree-Äge)*
$7,023 $24,252 $32,695
*Price may not include labor

30. Yearly Cost Comparison

31. Cumulative Cost
Comparison

32. Pesticide Treatment
Considerations
 We are approaching the near peak of
emerald ash borer pest pressure
 Recommend to treat with TreeAge
injections during this stressful period
 May switch to other, less costly products after

33. Summary
 Ash trees left untreated WILL die and will
have to be removed eventually
 Pesticide treatment must be done regularly
in order to protect the tree over time
 Get quotes from several tree care
companies before you decide on a
treatment
 If you choose to replant, select diverse,
native tree species

34. Additional Resources
 http://www.fairfaxcounty.gov/dpwes/envir
onmental/forest_pest.htm
 http://extension.entm.purdue.edu/EAB/P
DF/TreeCondition.pdf
 http://extension.entm.purdue.edu/EAB/
 www.emeraldashborer.info
 http://www.itreetools.org/design.php

35. For more information, please contact:
Fairfax County Urban Forest Management Division:
Forest Pest Management Branch
703-324-5304, TTY 711
PestMail@fairfaxcounty.gov
A Fairfax County Publication March 2016