Invasive Pest Targeting Crepe Myrtle, Could The UC Be Next?

An invasive pest targeting the Crepe Myrtle tree has made its way into Tennessee.

Officials say the Crepe Myrtle Bark Scale mostly effects Western and Middle Tennessee, but it could soon make its way to the Upper Cumberland.

Frank Hale serves as an entomology professor for the University of Tennessee Extension.

“People tend to move it, so if somebody by accident moves a plant that has it and brings it into your neighborhood, it could be all across town just from that infestation,” Hale said.

Hale said the exotic red-colored insects hide underneath a white scale cover and feed within the tree’s vascular system.

“It essentially removes the sap from the tree, which stresses and damages the cells of the Crepe Myrtle,” Hale said. “It’s kind of like drought stress.”

The bark scale originates from Asia and first came to the U.S. when it landed in Dallas, Texas in the 2000’s. From there, it made its way to Shelby County and has since spread to Tennessee’s Tipton, Madison, and Wilson Counties.

“These scales are small and when you move it somewhere they start to produce and lay lots of eggs,” Hale said. “Within a few years you can have literally hundreds, if not thousands of little insects on the plant.”

The Bark Scale is so small it can potentially flow in the wind or hitchhike on birds, squirrels and other animals,” Hale said. When infestation takes place, a fungi begins to form and turn the tree black.

“The plant also doesn’t bloom as well and you will start to see reduced blooming and much smaller blooms,” Hale said.

Some insecticides seem to keep the insects away, but Hale hesitates to use it because there are so many Crepe Myrtle in the southern United States.

Hale has also pondered using a pressure washer as a non-chemical way to combat the bark scale.

“We have to approach it a little different because within 10-15 years I think it’s going to be across the South,” Hale said. “Wherever you see a Crepe Myrtle, it’s probably going to have this insect infestation.”

In the meantime, if you see anything new and interesting on your Crepe Myrtle, you can contact Hale and his office at 615-835-4571.