This is an image of the Emerald Ash Borer.
- The Emerald Ash Borer (EAB) was first was found in Michigan in 2002 and quickly spread to 33 states by 2018. The borers made their way through the east coast and Louisiana all the way to Texas. The borer was confirmed to be in Fort Worth and Denton recently and research shows they will soon be in Dallas. Chemical treatments can protect a tree for 2-3 year`s but it is far too expensive to treat an entire forest ($15.00 – $20.00 per diameter inch of trunk).
- There are organic methods such as parasitic wasps, but they are not readily available and have limited effectiveness. In essence, we will soon lose all Ash trees in the forest and in North Texas.
- Between 2006 and 2008, the Trinity Forest contained 2,257 acres of mixed Ash and the term mixed ash means mostly Ash with a few other species mixed in and there were 121 acres of pure Ash…out of the 4,667 acres studied. In other words, almost half the trees in the forest will be lost to EAB.
- If we do nothing, it will:
- Reduce our air quality because trees clean our air through biogenic sequestration or a trees ability to capture and hold carbon dioxide, carbon monoxide, nitrogen oxide, sulfur dioxide and ozone. As these trees die, they release all the materials they sequestered back into the soil and then back into the air over time. In other words, the Ash are no longer carbon sinks but rather carbon emitters.
- Trees also filter particulate matter in the air and the loss of the Ash trees will reduce the life expectancy of people in the area and increase asthma as well as respiratory illness.
- Create a fire hazard. Having over 2,000 acres of dead trees greatly increases the potential for a devastating fire…just ask folks in Colorado or California.
- Reduce forest species diversity and wildlife diversity because one species will be wiped out.
- Increased topsoil run off as trees help reduce soil and water runoff.
- Reduced any carbon credit value unless we can show we are replacing the Ash and using the wood for products.
Possible remedies include:
Cutting some of the Ash for use in building furniture, flooring, paneling, among other uses, which allows the wood to hold all the sequestered materials longer as opposed to releasing it when they die. It also helps to provide funding to manage the forest in the future.
If we wait until the borer is found in Dallas, the Department of Agriculture will enact a quarantine and it will be tougher and more costly to remove the Ash and process the wood.
Forest & Wildlife Management Plan 2007
The forest and wildlife management plan the City of Dallas Urban Forest Advisory Committee worked on with Stephen F. Austin forestry experts in 2007, notes there are 4 primary dominant species in the forest and forest is not as species diverse as it should be. The plan calls for the removal of some dominant tree species such as Ash…in specific areas and replanting with other tree species. The plan mentioned EAB as a potential problem in the future, but the insect was not near Texas at the time.
Agrilus planipennis – Highly destructive to Ash (or Fraxinus) and unlike most borers, it attacks healthy trees. Listed below are some facts and treatment options:
- Found in Michigan in 2002 and quickly spread to 33 states by 2018.
- 4 stages, egg, larva, pupa, and adult.
- Each one lays 60-90 eggs on the bark surface and they hatch 1-2 weeks later and chew into the bark and outer vascular system. They overwinter and emerge in the spring.
- Affects all Ash species except Manchurian or Blue Ash (neither exist in Texas).
- In Texas, traps are put out in March to capture adults.
- Movement of infested wood or nursery stock increases the spread.
- Timely removal of infested trees, chipping the brush and burning logs can reduce the spread.
- Woodpeckers offer limited control and parasitic wasps show limited effectiveness.
- Systemic and injected insecticides offer 2 years of protection, but they are expensive ($16-20 per inch of diameter). Imidacloprid (Merit) drench or injection, Bidrin (injection) or sprays with Sevin (carbaryl), trunk injections with Permothrin (Tempo or Astro), or Emamectin Benzoate.
- 1/8 inch D shaped holes in the bark are symptoms, starting in the crown.
- Allen Smith at TFS is the state expert LASmith@TFS.TAMU.EDU
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