Hemlock Woolly Adelgid Training Background History of HWA

Hemlock Woolly Adelgid Training

Background History of HWA • Hemlock woolly adelgid (HWA) (Adelges tsugae) is a non-native insect pest that kills native eastern hemlock (Tsuga canadensis) • 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 and Mountains • 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

2011 HWA Infested County & Hemlock Native Range Map

2013 HWA Infested County Map

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 • Hemlock forests play a vital role in riparian areas as they prevent erosion on steep banks and provide shelter for wildlife by moderating temperatures in cold winter months and during hot summers days. 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

How to Identify HWA Eggs Hatching Crawlers Adults on Hemlock Twig

Life Cycle of HWA Hemlock woolly adelgid annual life cycle on hemlock in North America. (From Cheah et al. 2004)

Most Visible Sign of HWA 10

HWA Spread Methods • • • Wind Birds and animals Transplant of trees from infested areas Purchasing infested nursery stock People

Stages of Hemlock Decline Mortality Healthy Slight defoliation 7 3 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 • Because there are no natural predators, they multiply rapidly • Sheer numbers feeding on a hemlock results in loss of vigor and eventual death (3 to 7 years)

Methods Available to Treat HWA • • Soil Drench Soil Injection Stem Injection Foliage Spray or Basal Spray Soil Drench Method Kioritz Soil Injector 14

Soil Drenching • • Pros: Very easy to use Versatile system Lightweight Can use both HWA chemical products for this system • • Cons: Should not be used by trees next to a water source Have to move back leaf and duff litter to expose roots to drench or create holes around base of trees More room for chemical amount error Should not be used on steep slopes

Soil Injection Pros: • Can be used by trees next to a water source • Can give an accurate amount of chemical to a tree • Can use both HWA chemical products for this system • Versatile system NU-ARBOR 1 -Two Root Injector Cons: • Sometimes injector clogs up and must be cleaned • Injector equipment is more expensive to buy than soil drench • Hard to find Kioritz Soil Injectors are no longer being produced but other soil injectors are becoming available • The injector needs maintenance Kioritz Soil Injector

Stem Injection Pros: • Can be used by trees next to a water source • Can give a accurate amount of chemical to a tree • Less weight compared to a soil injection • • • Arbor-Jet Stem Injector • • • Cons: Limited on the types of chemicals that can be used Equipment costs more than other HWA treatment methods Must drill holes in trees to apply chemical but newer systems are becoming less invasive More time-consuming system compared to the other methods The injection system needs maintenance Creates wounds in the tree

Bark Spray Pros: Cons: • Good for treating • Cost for the chemical moderate to heavy Safari is more compared infestations to Imidacloprid • No drilling holes in trees to • One batch per tree apply chemical • Potential for drift • More potential for chemical exposure • Can only use Safari product in this system • Do not apply to wet bark, D. B. Smith Contractor Series Sprayer during rainfall or if rain is expected within 12 hours. 18

Foliage Spray Pros: • Good for treating foliage on small hemlocks • Good for treating light to moderate infestations • Can use both HWA chemical products in this system Field King™ Backpack Sprayer • • Cons: Should not be used by trees next to a water source The system is heavier compared to the other HWA treatment methods More potential for chemical exposure Foliar applications are best made in late spring or from July through September when the insect is not covered by protective wool

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 Only nearby rearing facility is the University of Tennessee and for public lands only At this time, only one company in Pennsylvania is selling beetles for private landowners Not good for treating light HWA infestation Better used on smaller diameter hemlocks Predator beetle preying upon HWA Photo by UT Dept. Ent. and Plant Path.

Treating Light Infestation • Full foliage, good green color in needles • Products-Imidacloprid, • Methods-Soil injection, soil drench, stem injection and foliage spray • Best time to treat-Spring and Fall but can be done yearround depending on weather and soil conditions

Treating Moderate Infestation • Thinning foliage, poorer color, needles starting to drop • Products-Imidacloprid, and Safari • Methods-Soil injection, soil drench or stem injection(imidacloprid only), foliage and bark spray(Safari) • Best time to treat-Spring and Fall but can be done 22 year-round, depending on weather and soil condition

Treating Heavy Infestation • Foliage very thin or missing in places, gray green, die back is staring or occurring • Products-Imidacloprid, Safari • Methods-Soil injection, soil drench, stem injection(Imidacloprid) and bark spray (Safari) • Best time to treat-Spring and Fall but can be done year-round, depending on 23 weather and soil condition

Equipment Cost of Each Method Soil Drench • Between $7. 95 -$8. 18 Soil Injector • Between $495 -$1, 700 Stem Injection • Between $394 -$400 Foliage/Bark Spray • Between $38. 75 -$67. 95 • (One 5 gallon jug or one 48 ounce Nalgene) (Hypo-Hatchet® Tree Injector or Arbor. Jet Quick Jet) Other systems cost up to $1, 500 or more (NU-ARBOR 1 -Two Root Injector or HTI Soil Injector) (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

Chemical Information Imidacloprid: • Used in any treatment method except bark spray • For light to moderate infestation • Treatment life is between 3 -5 years, depending on tree • Could affect honey bees and aquatic invertebrates • Must be kept out of direct sunlight • Can not be used in bark spray Safari (dinotefuran): • Used in any treatment method except stem injection • For moderate to heavy infestations • Do not apply directly to water, 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 • Treatment life is between 1 -3 years, depending on tree • Could affect shrimp and aquatic invertebrates *Please be sure to read and follow all label instructions when using any pesticides.

Cost Comparison of Chemicals Commonly Available Sizes Cost Range Per Inch Unit (commonly of Tree Diameter Inches of Tree sold sizes; not (not factoring for Diameter Treated Per including double dosing trees Unit shipping and ≥ 24 inches in handling) diameter) pouch of 4 1. 6 -oz water-soluble bags $0. 18 -$0. 26/inch of (generally the Generic Brands of 75% Water diameter (when smallest available $35 -$50/pouch Soluble Imidacloprid (75% 192 inches/pouch of 4 purchasing pouches amount); flats or of four WSP/WSB) barrels of 16, 48 or of 4) 88 1. 6 -oz water soluble bags Generic Brands of 21. 4 -22. 6% 1 gallon $120 -$180/gallon 1, 093 inches/gallon Flowable Imidacloprid (2 F/2 L) Imidacloprid Tablets(Cortect $120 -$180/bottle 125 inches/bottle of 250 -tablet bottle brand only) of 250 Imidacloprid 5% Injectable 1 Liter; case of 4 $250 -$300/Liter 250 inches/Liter Chemical (Ima-Jet brand only) Liters Dinotefuran 20 SG Soluable 3 pound bottle; 12 - $370 -$390/3 468 inches/3 pounds Granule (Safari brand only) ounce bottle pounds $0. 11 -$0. 16/inch of diameter $0. 96 -$0. 1. 44/inch of diameter $1. 00 -$1. 20/inch of diameter 26 $0. 80 -$0. 85/inch of diameter

Cost Comparison of Chemicals Inches of Tree Diameter Low Price High Price Treated Per Unit 10 in/26 in tree Generic Brands of 75% Water Soluble Imidacloprid (75% WSP/WSB) 192 inches/pouch of 4 $1. 80 -$9. 36 $2. 60 -$13. 52 Generic Brands of 21. 4 -22. 6% Flowable Imidacloprid (2 F/2 L) 1, 093 inches/gallon $1. 10 -$5. 72 $1. 60 -$8. 32 Imidacloprid Tablets (Cortect brand only) Imidacloprid 5% Injectable Chemical (Ima-Jet brand only) Dinotefuran 20 SG Soluble Granule (Safari brand only) *Tree greater than 24 inches have to be double dose 125 inches/bottle of 250 $9. 60 -$49. 92 $14. 40 -$74. 88 250 inches/Liter $10. 00 -$52. 00 $12. 22 -$63. 44 468 inches/3 pounds $8. 00 -$41. 60 $8. 50 -$45. 76

Steps for Private Landowners Treating HWA 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 1. Inspect trees to determine level of HWA infestation present: none, light, moderate or heavy. 2. Assess site conditions 3. Overall tactic 4. Collect tree data 5. Types of treatment and options for labor 6. Types of chemical for treatment 7. Chemical treatment methods 28

Steps for Private Landowners Treating HWA 8. Mixing rates 9. Estimate cost of treatment 10. Combine Tree Data and the Cost of Chemical *NOTE: It is the user's responsibility to read and follow all label instructions when using any pesticide materials. 29

For more information or technical assistance for landowners, please contact: Douglas Godbee 865. 318. 1371 Douglas. Godbee@tn. gov or visit www. protecttnforests. org