Controlling the Emerald Ash Borer Beetle Using an Ash Tree Predator

There are many people in the United States and in the state of Tennessee that rely on natural resources like trees every day without even recognizing it. The dining table at the family's home is constructed of ash. Towering ash trees provide welcome shade while citizens take in the beauty of city parks. Ash bats were first used by Little Leaguers to hit home runs. Moreover, these people may not realize that these and many other everyday amenities are suddenly at risk — all because of a small, seemingly unimportant bug that may already be evident among their ash trees. Ash trees (Fraxinus spp.) and the Tennessee timber industry, as well as the hundreds of other businesses that rely on ash wood and the thousands of Tennessee communities that are home to ash trees, are under threat from the Emerald Ash Borer (EAB) beetle.

Since the beginning of time, pests and disease have preyed on trees. A Davey Certified Master Arborist like Scott Johnson explains, "Trees generally live in a balance with the pests that eat on them. Trees have no natural defenses when an alien invasive species is introduced." Because of the lack of natural predators for the pest, the situation can quickly spiral out of control.

According to Therese M. Poland, Ph.D., and Deborah G. McCullough, Ph.D., entomology researchers for Journal of Forestry, the Emerald Ash Borer, a beetle generally found in Asia, has been damaging ash trees in the northeast United States and southern Canada since the 1990s (118). The EAB is thought to have arrived in the United States via international shipping pallets and containers made of wood. According to Juli Gould of the USDA Animal and Plant Health Inspection Service and Leah Bauer of the USDA Forestry Service, the EAB is not a severe problem in its native habitat. Due to the thicker bark of ash trees in Asia and the presence of EAB predators indigenous to the region (Gould and Bauer). ash trees are one of the most common trees to shade city blocks in North America, where the EAB population increased particularly swiftly," says Scott Johnson.

The EAB only affects ash trees. Eggs are laid on the ash tree's outer bark by adult beetles. The larvae dig into the bark after hatching from the eggs. Ash phloem is eaten by the EAB's larvae, resulting in the tree's demise over the course of four years, according to Gould and Bauer. Larval beetles emerge through the tree's bark, leaving D-shaped holes in their wake (Poland and McCullough 118). To find out if their trees have been affected, tree owners should keep an eye out for this telltale indication.

Humans are the primary means through which the EAB spreads (Genetically). People buy or carry wood from EAB-infested states or locations to use as firewood, and the EAB goes with them. Only half a mile may be spread each year without the help of humans, but the EAB has been spreading an average of 20 miles per year with human assistance, says Dan Herms, Professor of Entomology at Ohio State University. A quarantine has been put in place in regions where the EAB has been found by local, state, and federal authorities. In spite of this, individuals continue to transport firewood, which aids in the rapid spread of the EAB by making it easier for them to spread. A quarantine has been imposed on 18 Tennessee counties due to the discovery of the Emerald Ash Borer ("Emerald Ash Borer").

The EAB's potential impact on the Tennessee ash trees, local communities, and timber-related industries across the county is staggering. The EAB's detrimental effects on the timber industry are explained by Poland and McCullough:

Ashes are used in a wide range of products, including tool handles, baseball bats and furniture. At least six ash species are commercially important. Ash accounts for around 7.5 percent of the volume of hardwood saw timber in the eastern United States, with an undiscounted stumpage value of at least $25.1 billion in the eastern United States. In the United States alone, there are more than 8 billion ash trees, with 40 percent of them belonging to the large-diameter type. It was calculated that forest ash in the United States has a compensatory value of $282.3 billion (123).

According to Johnson, the EAB is a threat to the safety of residents in the affected areas because of the harm it does financially. A tree's degradation raises the chance of falling limbs and trees, according to him. Individuals and towns alike could lose billions of dollars if these ash trees are felled, and the beauty of many urban streets could be ruined. Richard S. Cowles, Ph.D. and other specialists estimate that "Ash species [.. ] represent 10 to 40% of the canopy cover in many communities," according to their research findings. Gould and Bauer estimate that 30 to 90 million ash trees, worth $20 to $60 billion, will be lost in the urban environment alone. Aesthetics on public and private property alike will be severely diminished.

EAB sightings have already been documented in 18 counties in Tennessee (Emerald Ash Borer Found in Middle Tennessee). Ash trees in Tennessee are at risk from the Emerald Ash Borer, which has been found in the state's urban areas and woods. The Emerald Ash Borer (EAB) is estimated to be worth more than $10 billion. Property values could be negatively impacted by the loss of these ash trees in Tennessee. Tree removal and replacement costs in towns and municipalities might reach the millions of dollars for taxpayers.

Even while there are various solutions to the EAB issue, none of them will work in every case. Poland and McCullough say that if the tree has not already been affected, prophylactic methods, such as insecticidal trunk injections, can save the ash trees (125). Even if a tree is already infested, early detection is key to a successful treatment. According to Johnson, one option for eliminating the EABs' food supply is to remove and burn the ash trees that surround the affected region in strips. Like a burn line in a forest, this prevents a forestfire by keeping the pest contained inside a designated border.

Educating the general people on the growing danger of the EAB infesting Tennessee and other afflicted areas is the first step in slowing its rapid growth. People will only take action if they are aware of the symptoms of EAB infestation and are convinced of the risk this parasite poses. EAB has been spotted in Tennessee, but residents and visitors are mainly ignorant of the quarantine that prevents the transportation of firewood from certain counties. As a result, quarantine only has a marginal impact on the situation. In order to regulate the EAB in the long run, public education campaigns such as PSAs and other media must be implemented. In addition, the quarantines must be strictly enforced by state officials, who will impose steep fines and other punishments for anyone who violates them.

References:

Cowles, Richard S. et al. “Coalition for Urban Ash Tree Conservation.” Emeraldashborer.info. USDA Forest Service, Michigan State University, Purdue University, Ohio State University. 6 Jan 2011. Web. 4 Nov. 2012.

“Emerald Ash Borer Beetle Discovered in East Tennessee.” Mghc.org. University of Tennessee Knoxville. 2 Aug. 2010. Web. 28 Oct. 2012.

“Emerald Ash Borer Found in Middle Tennessee for the First Time.” TN.GOV. Tennessee Department of Agriculture. 20 Sept. 2012. Web. 4 Nov. 2012.

“Genetically Engineered Trees to Fight Beetles.” Los Angeles, United States, Los Angeles: National Public Radio, 2008. ProQuest Research Library. Web. 1 Nov. 2012.

Gould, Juli and Leah Bauer. “Biological Control of Pests in Forests of Eastern United States: Emerald Ash Borer.” forestpestbiocontrol.info. UMass Amherst. n.d. Web. 28 Oct. 2012.

Johnson, Scott. Personal Interview. 13 November 2012.

Poland, Therese M., and Deborah G. McCullough. "Emerald Ash Borer: Invasion of the Urban Forest and the Threat to North America's Ash Resource." Journal of Forestry 104.3 (2006): 118-24. ProQuest Research Library. Web. 1 Nov. 2012.