HEMLOCK WOOLLY ADELGID

Tennessee Division of Forestry

Background History of HWA Hemlock woolly adelgid (HWA) (Adelges

tsugae) is a non-native insect pest that kills native eastern and carolina hemlocks (Tsuga canadensis & Tsuga caroliniana)

HWA was first discovered in Virginia in 1951 and as of 2012 has spread to 18 eastern states where it has significantly altered or reduced native hemlock populations

Background History of HWA in Tennessee

In Tennessee HWA was discovered in Sevier & Blount counties in 2002 and has since spread west to the Cumberland Plateau

Much of the hemlock population in the Blue Ridge eco-region of our state has already been lost or is severely threatened by this pest

Since 2002, HWA has spread to 36 Tennessee counties

HWA Threats HWA is the single greatest threat to

hemlock health and sustainability in the eastern US and is comparable to Dutch Elm Disease and American Chestnut Blight in potential impacts

If left untreated, HWA can kill a hemlock tree within 3 to 7 years of infestation

HWA Threats Hemlock forests play a vital role in riparian areas as

they: - prevent erosion on steep banks which helps to prevent

disruptive water quality issues - provide shelter for many wildlife species - keeps water temperatures moderate in cold winter

months and cool during hot summers days for aquatic species

HWA can potentially destroy these values and forever change the forest landscape!!

Why Hemlocks are Important to Tennessee

Aesthetic Value Economic Value

Environmental Value Personal Value

HWA Spread Methods Wind Birds and animals Transplant of trees from

infested areas Purchasing infested nursery

stock People

Most Visible Sign of HWA

Healthy

Stages of Hemlock Decline

Slight defoliation Mortality

3 7

Years

How Does HWA Kill Trees? Nymphs and adults insert a

stylet near the base of needles and feed on sap and nutrients

May inject a saliva into the tree to disrupt plant growth

Multiply rapidly- no natural predators

Sheer numbers feeding on a hemlock results in loss of vigor and eventual death (3 to 7 years)

Biological Controls: Predator Beetles

Pros: Best chance for long-term

control of HWA Can be used on large

inaccessible areas Good for treating moderate

to heavy HWA infestations Three different species of

beetles are being raised at UT

Cons: Expensive: beetles can cost

between $2-$3 each & most areas require thousands of beetles for introduction

Successfully introduction requires extremely specific site conditions

Only nearby rearing facility is the University of Tennessee and for public lands only

Two companies in Pennsylvania and North Carolina are selling beetles for private landowners

Laricobius nigrinus beetle being release on state forest land

Chemical Information-Imidacloprid

Imidacloprid: For light to moderate infestation Treatment life is between 3-8 years,

depending on tree Must be kept out of direct sunlight

Chemical Information-Imidacloprid

Imidacloprid is a Neonicotinoid insecticide are synthetic derivatives of nicotine, an alkaloid compound found in the leaves of many plants in addition to tobacco.

Could affect honey bees and aquatic invertebrates

Treatment Methods Use: Soil Drench, Soil Injection, Stem Injection and Foliage Spray

Chemical Information-Dinotefuran

Dinotefuran (Safari): For moderate to heavy infestations Do not apply within 20 feet of direct water

source, or to areas where surface water is present or to areas below the mean high water mark

For trees in forests that are pollinated by bees or other invertebrates, make applications post-bloom

Chemical Information-Dinotefuran

Must be kept out of direct sunlight Treatment life is between 1-3 years,

depending on tree Could affect shrimp and aquatic

invertebrates Treatment Methods Use: Soil Drench, Soil

Injection, Foliage and Bark Spray

*Please be sure to read and follow all label instructions when using any pesticides.

Methods Available to Treat HWA

Soil Drench Soil Injection Stem Injection Foliage Spray or Basal Spray

Soil Drench Equipment

Kioritz Soil Injector

Soil DrenchingCons:

Have to move back leaf and duff litter to expose roots to drench

More room for chemical amount error

Should not be used on steep slopes

Can not be used at least 5 foot from a water source for Imidacloprid and 20 feet for Dinotefuran

Pros: Very easy to use Versatile system Lightweight Can use both HWA chemical

products for this system

Soil Drench Equipment

Soil InjectionPros:

Can give an accurate amount of chemical to a tree

Can use both HWA chemical products for this system

Versatile system

Cons: Sometimes injector clogs up

and must be cleaned and needs maintenance

Hard to find Kioritz Soil Injectors are no longer being produced but other soil injectors are becoming available

Can not be used at least 5 foot from a water source for Imidacloprid and 20 feet for Dinotefuran

NU-ARBOR 1-Two Root Injector

Kioritz Soil Injector

Stem InjectionPros:

Can be used by trees next to a water source

Can give a accurate amount of chemical to a tree

Less weight compared to other treatment methods

Cons: Can only use Imidacloprid

chemical in injector Equipment costs more

than other HWA treatment methods

Must drill holes in trees to apply chemical but newer systems are becoming less invasive

Creates wounds around the base of the tree

Trees need to have greater than 50% live crown left for successful treatment

Arbor-Jet Stem Injector

Bark Spray

Pros: Good for treating moderate

to heavy infestations No drilling holes in trees to

apply chemical

Cons: More potential for

chemical exposure and drift

Can only use Dinotefuran chemical in this system

Do not apply to wet bark, during rainfall or if rain is expected within 12 hours.

Can not be used within the 20 feet of a water source

D.B. Smith Contractor Series Sprayer

Foliage SprayPros:

Good for treating foliage on small hemlocks with trees less than 30 feet in height

Good for treating light-heavy infestations

Cons: Can not be used at least 5

foot from a water source for Imidacloprid and 20 feet for Dinotefuran

More potential for chemical exposure and drift

Best to begin applications before the onset of high pest populations

Foliar applications are best made in late spring or from July through September when the insect is not covered by protective wool

Field King™ Backpack Sprayer

Treating Light Infestation Full foliage, good green

color in needles Products-Imidacloprid,

Dinotefuran Methods-Soil injection,

soil drench, foliage spray and stem injection

Best time to treat-Spring and Fall but can be done year-round depending on weather and soil conditions

Treating Moderate Infestation Thinning foliage, poorer

color, needles starting to drop

Products-Imidacloprid, Dinotefuran

Methods-Soil injection, soil drench, foliage, bark spray and stem injection

Best time to treat-Spring and Fall but can be done year-round, depending on weather and soil condition

Treating Heavy Infestation Foliage very thin or

missing in places, gray green, die back is starting or occurring

Products-Imidacloprid, Dinotefuran

Methods-Soil injection, soil drench, bark spray and stem injection

Best time to treat-Spring and Fall but can be done year-round, depending on weather and soil condition

Equipment Cost of Each Method

Soil Dench Between $7.95-$8.18(One 5 gallon jug or one 48 ounce Nalgene bottle)

Stem Injection Between $394-$400(Hypo-Hatchet® Tree Injector or Arbor-Jet Quick Jet) Other systems cost up to $1,500 or more

Soil Injector Between $495-$1,700

(NU-ARBOR 1-Two Root Injector or HTI Soil Injector)

Foliage/Bark Spray Between $38.75-

$67.95(D.B. Smith Contractor Series Sprayer or 4-Gallon Capacity Field King™ Backpack Sprayer)

*Please note prices will vary with sales tax, shipping cost local availability and any extra accessories you may need to buy

Cost Comparison of Chemicals

Cost Range Per Unit (commonly sold sizes; not including shipping and handling)

Inches of Tree Diameter Treated Per Unit

Cost Range Per Inch of Tree Diameter (not factoring for double dosing trees ≥ 24

inches in diameter)

Generic Brands of 75% Water Soluble Imidacloprid (75% WSP/WSB)

$34-$50/pouch of 4 at 1.6g per bag

192 inches/pouch of 4 at 1.6g per bag

$0.17-$0.26/inch of diameter (when purchasing pouches of 4)

Generic Brands of 21.4-22.6% Flowable Imidacloprid (2F/2L) $105-$180/gallon Up to 3,840 inches/gallon $0.05-$0.14/inch of diameter

Imidacloprid Tablets(Cortect brand only) $112-$180/bottle of 250 125 inches/bottle of 250 $0.90-$0.1.44/inch of diameter

Imidacloprid 5% Injectable Chemical (Ima-Jet brand only) $250-$302/Liter 250 inches/Liter $1.00-$1.21/inch of diameter

Dinotefuran 20SG Soluable Granule (Safari brand only) $357-$390/3 pounds 468 inches/3 pounds $0.76-$0.85/inch of diameter

Steps for Private Landowners Treating HWA

1. Determine your goals and objectives for your forest as well as for your hemlocks. Treating your hemlocks should be a long term commitment that may involve multiple treatments. Developing a comprehensive forestry management plan is highly encouraged

2. Inspect trees to determine level of HWA infestation present: none, light, moderate or heavy.

3. Assess site conditions (soils, terrain, slopes and accessibility of site)

Steps for Private Landowners Treating HWA

4. Collect tree data (record for each trees dbh and number of trees per acre for site)

5. Based on steps 2-4, determine treatment strategy (chemical type, amount of chemical, labor and treatment method)

6. Estimated cost of Treatment

7. Develop long term budget for continue treatment for HWA

*NOTE: It is the user's responsibility to read and follow all label instructions when using any pesticide materials.

For more information or technical assistance please contact:

Heather Slayton615-218-4377

Heather.Slayton@tn.govor visit

www.protecttnforests.org