Emamectin Benzoate(EB), a glycoside insecticide,and the active ingredient in Tree-Age G-4.

1.Tree-Age contains 4% EB per quart or .36 lbs per gallon. The otheringredients are fluids to help absorb EB into the tree’s system. Since Tree-Age is also diluted with water, there is approximately 1 teaspoon of EB injected into the average tree, a 16” DBH oak.

2.EB does go into the leaves but composted leaves are not harmful to soil or water.

3.The firewood of any EB-injected tree which doesn’t survive is safe to burn in a fireplace or woodstove.

4.If a dead, injected tree is chipped, it is safe to compost into the soil. EB is parts per billion in a tree.

5.EB does not harm woodpeckers. They do not want to eat dead bugs. They have the ability to listen for the sound of chewing inside the tree and will only peck there—not where EB is in action.

When to Inject

1.Inspect all of your trees. Know what condition they are in and what your priorities are for saving them. Injection is not done only once. It will need to be repeated every 3-5 years.

2.On any infected tree, use a tiny dab of paint to mark the D-holes. Round holes are not GSOB. Then count. Numbering and/or mapping your oaks is very important.

3.Standard rating of a GSOB- infected oak showing the small GSOB D-shaped holes on its trunk: 1-5 holes= slightly infested. 5-15 holes = moderately infested.30 or more holes = heavily infested.

4.There is a limited time period for injection since the oaks are dormant from June through September. If rains arrive in October, treatment can certainly begin. At this writing, March 2021, we have been in a drought.

5.April is one of the best times to treat. The Tree Age fluid needs 4-6 weeks to move throughout the tree and enable the tree to fend off GSOB. Results will depend on the health of the tree, how much rainfall or water it has had and the outside temperature. Soil temperature must be above 45 degrees. When GSOB is in the larvae stage, it is feeding and taking in chemical. At pupae stage, before hatching, it is no longer eating or absorbing the chemical. There is one cycle of GSOB per year. We often see a tree “die suddenly” but GSOB has probably been in that tree for 3-4 years. The tree continues to pull water and nutrients between the infested areas. Eventually, the insect girdles the tree and shuts down all water and nutrients to the tree. GSOB begins at the top/canopy of a tree and works its way down the tree.

6.The G-4 version of Tree-Age (G=general use) is only for homeowners to use on their own property. A homeowner cannot inject trees on another’s property. The DIY process requires study and attention to detail. If not done properly, the tree may die. A certified arborist trained in tree injection has been injecting oaks here for almost 5 years with great success. Violations will cause us to lose our DIY options. G-4 has been banned in the state of New York.

7.Injecting requires special equipment which can be used again and again. However, it is an expensive investment.

8. Watering an oak tree before treatment may be necessary if rainfall is not significant during the rainy season. 90% of an oak’s roots are within 8” of the soil surface. Water 10’ from the trunk even though it is well known that an oak’s roots often extend 1. 5 or more times the height of the tree. Since the Green Valley wells are low, water would need to be brought in.

9.Halo Effect: This was first noticed in the untreated ash trees surrounding ash trees which were treated for EAB with Tree Age. Many of them did not become infected. Beetles eating the EB-dosed leaves do not survive, unable to fly to another tree. This will probably be the same for GSOB since it is the same genus as EAB.

10. Slime Flux: The only side effect of injection. It’s ugly but it doesn’t kill the tree. It is common in oaks since they must be treated in the Spring when sugar and protein are in the sap. Anaerobic bacteria gets into the injection sites when drilling into the tree. It is easily treated with bactericide or fungicide. It is also helpful to spray hydrogen peroxide on each injection site before and after drilling.

11.G4 moves both directions through the tree’s phloem. It does not contaminate our ground water.

12.Monitor your oak trees. Check them in August/September as well as in the spring. Be sure to check canopy and look for any additional GSOB holes. Trees should be stable for 2-3 yrs, sometimes 5 yrs. Rainfall and surrounding infestation will play a role in the health of our oaks.