Embed Size (px)
Citation preview
Emerald Ash BorerHistory, Biology and Considerations for
Management
The Davey Institute
Early History
Summer 2001, Detroit» Early reports of dying ash» Two lined chestnut borer thought
to be causal agent
Winter/Spring/Summer, 2002» David Roberts, MSU pathologist,
rears unknown metallic green beetle from infested logs
» Beetle later identified and– Given the name ‘emerald ash
borer’
Fall, 2002» 5-7 million trees affected in 6 county
area of SE MI were identified as infested
History
Discovered July 2002: MI and Ontario
Detroit: Michigan State
University
Windsor: CFS & MNR forest
health staff
Natural dispersal:
speculative, probably 10
km/yr
EAB has greatly extended its
range in Ontario (mostly as a
result of human activities).
Potential Impact
Widespread mortality is
already being experienced in
several areas of the
province.
Up to 10 billion forest trees
threatened in Canada and
US ~1-2% of urban canopy
threatened» Up to 35% in some areas
Where Did EAB Come From?
Probably arrived on crating
materials in Detroit/Windsor
Area» Much heavy equipment is
manufactured in Asia because
of the booming steel industry
Researchers now believe
the infestation was
already 15 to 20 years old
when first identified in
2002
How Did They Get Here?
Crating Materials
» Fresh wood used for
crating
Crating often not
fumigated
Thick slat size
» Allowed larval and
pupal Stages to
survive the trip intact
» Adults emerged from
discarded crating
After emerging, tiny
larvae move to
cambium area
Feed on outer
xylem, cambium and
phloem tissues
Larvae do the
damage, not the
adults
EAB Biology: Life CycleLarval Stage
xylem
phloem
Tunnels typically S-
shaped under low
population conditions
As populations
increase, tunnels
become more variable in
shape Feed from June through
October
EAB Biology: Life CycleLarval Stage
EAB Biology: Life CycleLarval Stage
Infestations begin in upper
crown, as is typical of most
flatheaded borers» Branches over 6 inches in
diameter with rough bark have
more larvae
» Look there first
By time larval galleries are
present low on trunk,
infestation is already several
years old
EAB Biology: Life CycleLarval Stage
Larvae eventually
destroy the entire
vascular system of
the tree.
EAB Biology: Life CycleAdult Emergence
Adult Emergence» Adults chew their way
from their overwintering
chamber to the surface
» Leave behind a D-shaped
emergence hole
– Can be oriented in
any direction
– Hard to see on rough
bark
EAB Biology: Life CycleAdult Dispersal
Beetles are good flyers
and can fly several miles
Most fly much shorter
distances if host trees are
nearby» Purple traps used to
monitor
They can also hitchhike
on vehicles and wood
debris
Thinning (not
dieback) is
typically one of
the first
symptoms
noticed when
trees are in leaf
EAB Biology: Symptoms and SignsCrown Thinning
Treatments applied
beyond 30% thinning
are likely to be
unsuccessful
» Note that a tree with
30% thinning still looks
pretty good
EAB Biology: Symptoms and SignsCrown Thinning
Crown Thinning
» Dieback follows
thinning
EAB Biology: Symptoms and SignsCrown Thinning
EAB Biology: Symptoms and SignsCrown Thinning
It is common to
see trees with
varying levels of
thinning on the
same site
EAB Biology: Symptoms and SignsCrown Thinning
Expected Thinning Over Time
EAB Biology: Symptoms and SignsWater Sprouts
As the crown thins/dies,
watersprouts often develop
on the trunk and lower
scaffold branches
Tree is attempting to replace
lost foliage
Can indicate the current
point of vascular disruption
EAB Biology: Symptoms and SignsWoodpecker Activity
Woodpeckers chip
off bark looking for
larvae
» This is especially
true during winter
months
» Excellent visual cue
to EAB presence
» Can consume 20 to
55 percent of larvae
Do Nothing
» Based on what we know now, ash tree will die
» Dead ash trees quickly fall apart
Remove ash trees and replace with other
species
» Begin with lowest quality trees
Treat Trees
» Understand there will be losses, even with
treatment
EAB Management: Treatment ProtocolsThree Basic Options
Decide if keeping the ash tree(s) is(are) worth the cost to protect» Should consider the value of the existing trees
Decide how many trees to protect» Based on location, condition, budget
Recommend treatment protocols appropriate to situation
EAB Management: Treatment OptionsHow Do We Proceed?
Cultural Options» Initially healthy trees should be able to last longer
and/or recover more quickly with proper watering and Soil Care/Fertilization treatments when combined with appropriate chemical treatments
Chemical Treatments» Trunk injection with TreeAzin
EAB Management: Treatment OptionsHow Do We Proceed?
» Systemic Insecticide is produced from extracts of Neem Tree seeds
» Injected into the trunk of ash trees
» TreeAzin™ is exempt from Ontario's Cosmetic Pesticide Ban Act.
Treating EAB With TreeAzin
» Early summer injections (5ml/cm dbh) provide effective control of EAB for two seasons
» 95% of EAB larvae are killed
» 98% of eggs laid are not viable
Effective against Emerald Ash Borer
» Among many other benefits, urban trees reduce air and noise pollution, increase property value, help reduce stress, provide wildlife habitat, and add beauty to a community.
Treatment Pros and Cons
Diplodia Tip Blight
What is Diplodia?
Fertilization
How and why to fertilize your trees
» Low salt index and slow-release action does not burn delicate feeding roots.
» Trees resist and recover from environmental and pest problems
Fertilize with ARBOR GREEN PRO
Promotes Root Health» Improve TreeAzin
up-take» Injected into soil
at feeding root zone
» Uniform growth for improved root/soil contact
Maintain Tree Health
Replacement Trees
Chanticleer Pear Serviceberry Autumn Blaze Maple
Replacement Trees
Autumn Fantasy Maple Ivory Silk Lilac
