emerald ash borer history, biology and considerations for management the davey institute

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?

Pruning Techniques

Proper Pruning video

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