Advanced Intelligence Report Treating For Emerald Ash Borer With Bayer Advanced Tree and Shrub Insect Control Soil Drench Dr. Bruce Stewart, Bayer Advanced Consumer Products Emerald Ash Borer (EAB) is the latest high-profile invasive insect pest to attack ornamental trees in North America. A native of Asia, it was first identified in the Detroit, MI area in 2002. EAB has since been found in Ohio and Indiana, and has the potential to be spread wherever ash trees are found in North America. Efforts to contain EAB are ongoing. Tree mortality is caused by the larvae or immature stages, which feed underneath the ash tree s bark and can be easily spread by transport of ash logs, firewood, and nursery stock. Current containment strategies for EAB varies from state to state and may consist of elimination of ash trees in infested areas, extensive surveying of high risk areas, implementation of quarantines for ash products, and insecticidal treatments of EAB infested trees or treatment of trees near EAB infested sites. One insecticidal treatment that has shown promise of protecting ash trees from the EAB is Bayer Advanced Tree & Shrub Insect Control (1.47% imidacloprid, tradename Merit). If used properly, a soil drench of this insecticide can be used to protect ash trees from EAB. Below are some commonly asked about the product and its application. 1
Advanced Intelligence Report 1. How do you apply the product? Use of Bayer Advanced Tree & Shrub Insect Control is straightforward. Simply mix 1 oz of Bayer Advanced Tree & Shrub Insect Control for each 1 inch of circumference around the ash tree and place this amount in 1 gallon of water. The tree s circumference can be measured with a tape measure exactly as you would measure your waist size. When measuring a tree s circumference, place the tape measure at the level of your chest. For example: If the ash tree measures 20 inches around, place 20 oz of the product in 1 gallon of water and pour around the base of the ash tree. If the ash tree is larger than 50 inches around, put the appropriate amount of product in 2 gallons of water and pour around the base of the ash tree. 2. When is the best time of year to apply the product for EAB? We recommend that treatments be applied in early spring (preferably before mid-may). There is some evidence that fall applications may be effective as well but further research is needed to confirm this. Soil drenches should not be applied if the ground is frozen or waterlogged as the material may not soak into the ground to be absorbed properly by the tree s roots. 3. Where should the product be applied on the tree? Pour the mixed solution on the base of the tree where it flows down over the root flare and directly around the base of the tree. The tree base is where the highest concentration of roots is found (as can be visually observed when a tree blows over in the wind). Also, roots found directly around the tree trunk are very successful in taking up the product. Applications of imidacloprid made directly around the tree s trunk work most effectively in controlling insect pests (Journal of Arboriculture 24:297Pour solution on tree root flare. 299 and several other published scientific reports). 2
4. Can you treat ash trees already infested with EAB and have success? For best results, you should start treatments with Bayer Advanced Tree & Shrub Insect Control before your ash tree becomes infested and before any dieback is evident. Healthy trees with little or no dieback have the best chance of surviving EAB when drenched. Ongoing research shows that trees with levels of dieback up to 50% do not get worse after being drenched for 2 consecutive years but the ability to cure heavily infested trees is still in question and more research is needed. 5. Do you have to treat ash trees every year for EAB? It is currently recommended that ash trees be treated every year to keep them protected from EAB. 6. Will this product harm my trees? If used according to the label directions, this product will not harm ash trees. Several research trials have demonstrated that imidacloprid not only protects plants from insects but also provides other significant benefits, such as increased growth, disease suppression, increased yield, and increased stress tolerance. 7. How long will the product protect my ash tree from the EAB? A single application of this product will provide 12 months of protection to ash trees. Some university researchers are recommending two applications per year for ash trees that are larger than 20 inches in circumference. 8. How long does it take the product to move up through the tree? Many factors are involved in the process of moving the insecticide through the tree s tissues, such as relative health of the ash tree, soil type and condition, and environmental conditions. Translocation (the movement of the chemical up from the roots to the above ground plant parts) of Bayer Advanced Tree & Shrub Insect Control may require a week to a month in small trees (less than 20 inches in circumference) and may take 2 to 3 months in larger trees. 3
9. Can this product be used at the time of planting? Yes. It is recommended that the soil drench be applied immediately after the tree is planted, to be followed by a thorough watering 10. Can a homeowner treat his or her own trees effectively? Bayer Advanced Tree & Shrub Insect Control was developed to be very effective yet easy to apply. Most homeowners will have no trouble achieving the desired results if they carefully follow label instructions. 11. Can large ash trees (over 20 inches in circumference) be protected from EAB with Bayer Advanced Tree & Shrub Insect Control? Uninfested trees of any size can be protected from EAB with Bayer Advanced Tree & Shrub Insect Control. Also, smaller (those less 20 inches in circumference), moderately-infested trees can be protected from EAB with a soil drench. Protection of infested trees that exceed 20 inches in circumference is less certain and research is currently being conducted to determine if dieback can be arrested by an imidacloprid soil drench. Preliminary research has suggested that dieback can be halted in large ash trees receiving 2 consecutive years of soil drenching with Bayer Advanced Tree & Shrub Insect Control but more studies are needed to confirm this. 12. What is the cost for protecting ash trees with Bayer Advanced Tree & Shrub Insect Control? A 32 oz bottle of Bayer Advanced Tree & Shrub Insect Control costs approximately $20. At that price, each circumference inch of the tree will cost approximately $0.60 to protect. Some examples of the tree trunk size (at chest height) and corresponding cost per year to treat are provided below: Approximate Circumference of Tree Trunk Cost to Treat Tree Golf Ball Size $3.00 Soft Ball Size $8.00 Basketball Size $19.00 4
13. How safe is the product? What precautions are needed? Since Bayer Advanced Tree & Shrub Insect Control is a targeted treatment applied to the base of trees, it is not sprayed up into the tree canopy. The application method reduces exposure to non-target organisms. For safety s sake, it is recommended that children and pets be kept clear of freshly treated trees until the treatment has completely dried. 14. Does Bayer Advanced Tree & Shrub Insect Control have a guarantee? If the product is used appropriately and the homeowner is not satisfied, Bayer Advanced will refund the original purchase price of the product. 15. Under what conditions would the use of Bayer Advanced Tree & Shrub Insect Control NOT be appropriate? If the ash tree has severe dieback (more than 50% dieback), it will probably not respond well to treatment. However, if the tree is important or valuable, it may be wise to treat for one year and then re-evaluate its condition before deciding to remove it. When using the product, don t apply if the ground is frozen or waterlogged or if the tree is on a steep slope or next to a body of water. Don t apply the product if there is a probability that it will flow to a non-target site. 16. Other than EAB, what insects does Bayer Advanced Tree & Shrub Insect Control? Aphids Adelgids Scales Psyllids Lace bugs Mealybugs Leafhoppers Thrips Royal palm bugs Whiteflies Sawfly Black vine weevil Pine tip moth Leafminers Leaf-feeding beetles Flatheaded Borers: (including Bronze Birch, Alder, and Emerald Ash Borers) Roundheaded Borers: (including Asian Longhorned Beetle and Eucalyptus Longhorned Borers) 5
17. Are there insects that Bayer Advanced Tree & Shrub Insect Control does not affect? Some of the more common ornamental pests that the product does not control are mites, gypsy moth, fall armyworm, and eastern tent caterpillar. 18. What research is being done on the effect of Bayer Advanced Tree & Shrub Insect Control on EAB? Bayer is supporting a number of research scientists to better understand the impact imidacloprid has on protecting ash trees from EAB. Specifically, research efforts are focused on determining the influence of application timing, tree size, and % dieback on imidacloprid s ability to protect ash trees from EAB. For more information, visit www.bayeradvanced.com Better Thinking, Better Results 6