DRC_emerald ash borer.jpg

An adult emerald ash borer beetle is about a half-inch long with a metallic green body and wings that form a V when folded over its back.

DRC_Michele Rawleigh.jpg

Michele Rawleigh

The recent discovery of the emerald ash borer in Fort Worth has prompted several actions designed to slow the advance of the infestation, including a quarantine on the movement of some wood products out of Tarrant County.

One Texas A&M Forest Service estimate has Texans spending $19 billion over the next 20 years as a result of the emerald ash borer.

The emerald ash borer, a native of Asia, was first recorded in Michigan in 2002 and is now found in 35 states and Canada, having killed hundreds of millions of ash trees in its path. The first sighting in Texas was in 2016 near Caddo Lake. Recently EAB was confirmed near Eagle Mountain Lake in Tarrant County.

With a recommended treatment zone of 15 miles from the infestation epicenter, the beetle is knocking on Denton County’s door. The Texas A&M Forest Service has been monitoring traps in the county for the past two years with no captures yet. However, included in the county’s traps this year will be two in the southwestern portion closest to the outbreak.

An adult emerald ash borer beetle is about a half-inch long with a metallic green body and wings that form a V when folded over its back. The S-shaped tunnels created by the larvae are found just under the bark. The tunnels interrupt the flow of water and nutrients, killing the tree in a few years.

When the larvae have finished their life cycle inside the tree, they chew D-shaped exit holes through the bark and the adult green beetles emerge to find their next victims.

Symptoms of an infested ash tree may include any or all of the following:

  • Dead branches and thinning of the crown.
  • Leafy shoots that sprout directly from the trunk.
  • Splitting or missing bark that exposes the tunnels.
  • Extensive woodpecker activity.
  • D-shaped exit holes.

There are several preventative treatment options for ash trees within the 15-mile recommended treatment zone. They consist primarily of insecticide injections into individual ash trees or into the surrounding soil to be absorbed by the tree. However, the treatments need to be repeated frequently, annually to every two or three years depending on the method.

Removing undesirable or unhealthy ash tree specimens is one way to slow EAB’s advance. It is generally more cost effective though to treat healthy, mature ash trees than to remove and replace them.

Other activities that will help prevent or slow the spread of EAB:

  • Consider working on treatment plans as a neighborhood to prevent EAB from gaining a foothold.
  • If planting a new tree, select a native tree other than ash to increase the diversification of our tree population.
  • Do not transport firewood, lumber, ash nursery stock or other regulated wood products out of quarantine areas.
  • If you see a shiny green beetle that you think you might be an emerald ash borer, report it to the EAB Hotline at 866-322-4512.

For more information, visit the Texas A&M Forest Service website at www.tfsweb.tamu.edu/eab/ or the Emerald Ash Borer Information Network at www.emeraldashborerinfo.org.

Michele Rawleigh is a Denton County Master Gardener.

Recommended for you