2019-008 Emerald Ash BorerDate: January 18, 2019 Report No. 2019-008
INFORMAL STAFF REPORT
TO MAYOR AND CITY COUNCIL
SUBJECT:
Provide information on the confirmed spread of the Emerald Ash Borer to the DFW region.
EXECUTIVE SUMMARY:
Emerald Ash Borer (EAB) is an invasive exotic beetle native to Asia that was first discovered
near Detroit, Michigan in 2002. EAB is responsible for the death of millions of ash trees across
the country due to larvae feeding on the inner bark of the tree and disrupting a tree’s ability to
circulate and process water and nutrients. EAB has been confirmed in Texas and will soon be a
concern for the City of Denton’s ash trees. As such, we want to provide an update to Council on
what the Parks and Recreation Department is doing to prepare for this issue.
Since it was first detected in Michigan, the beetle has spread to 35 States and 6 Canadian
provinces. As of December 2018, the Texas A&M Forest Service confirmed reports of EAB in
Tarrant County (northwest of Fort Worth). EAB has infested and killed ash trees in the Eagle
Mountain Lake area (less than 30 miles away from Denton).
DISCUSSION:
The State of Denton Urban Forest 2016 Report calculated Denton’s urban forest to consist of
about 4% (138,000) ash trees, including trees located on public and private properties. Ash trees
represent the eighth most populous tree in Denton with a structural (replacement) value of
$102.6 million. Ash also provide approximately $287,000 in annual environmental benefits such
as carbon sequestration, avoided water run-off, pollution removal, and energy savings.
Options for managing EAB are:
1. Commit to a preventative treatment program for the life of the tree.
2. Treat ash trees to allow for systematic removal and replacement over time.
3. Remove the tree and replant with a different species of tree.
While treatments can begin after a tree has been infested, generally by the time EAB is detected
the infestation is too far-gone (less than 50% of crown remaining) for treatments to be effective.
Depending on the insecticide used, treatments are required annually, biennially or triennially.
Staff is developing an EAB Preparedness Plan, which includes a community outreach strategy.
The media for community outreach may include information sharing via the City website, social
media, pamphlets, and brochures. This plan is based on an outline provided by the Texas A&M
Date: January 18, 2019 Report No. 2019-008
Forest Service entitled Community Forest Planning Guide: EAB. The objectives of this plan are
to:
1. Reduce the financial cost to manage EAB establishment in the community
2. Reduce tree canopy cover losses from EAB
3. Reduce the amount and severity of damage and loss to people, property, the economy and
the environment that results from tree loss due to EAB
4. Maintain community forest health, safety, and benefits
5. Maintain and enhance confidence in elected officials, city staff, and programs
EAB will also be a topic of discussion in the forthcoming Urban Forest Master Plan.
Please see the following websites and attachments for additional information:
http://www.emeraldashborer.info/
https://www.aphis.usda.gov/aphis/maps/plant-health/eab-storymap
https://www.aphis.usda.gov/aphis/ourfocus/planthealth/plant-pest-and-disease-programs/pests-and-
diseases/emerald-ash-borer
STAFF CONTACT:
Haywood Morgan, Jr.
Urban Forester, Parks and Recreation
(940) 349-8337
Haywood.Morgan@cityofdenton.com