Northsiders with crape myrtles, beware.
According to a report from the Mississippi State University extension service, crape myrtle bark scale poses a great threat to southern crape myrtles.
“It threatens to turn what has historically been a beautiful, low-maintenance landscape tree into an unsightly, high-maintenance landscape tree,” the report reads.
Bark scale was first found on a crape myrtle in Mississippi in the spring of 2015.
If the trees are not treated, they will become covered in a black, sooty mold.
Sooty mold does not mean a tree has bark scale. However, if white, felt-covered scales that bleed pink when punctured appear, that is a sign that a crape myrtle has bark scale.
Bark scale on plants that are heavily infested is easy to spot.
Destruction of the infected crape myrtle is not always necessary. However, sometimes it is the best way to remove the problem.
Donna Yowell, the executive director of the Central Mississippi Urban Forestry Council, said that the council does not always advise that crape myrtles with bark scale be destroyed.
“There are several things you can do,” Yowell said. “There are many spray programs available, so that complete removal is not always necessary.”
Barchelai Smith at Green Oak Garden Center said their chemicals for treatment of bark scale have been flying off the shelves.
Smith said there was an influx of people seeking treatment options for their crape myrtles in the last few months.
“There have been tons of people coming in for that,” Smith said. “What we are recommending is a couple of systemic controls that the extension service is recommending. That stuff has been flying off the shelf for the past two months.”
He added that the extension’s recommended treatment regimen is still being researched.
“They’re trying to find better ways of treating it,” he said. “It’s a new thing that is spreading pretty quickly. They’re still researching the best way to control it. We have several different chemicals available for sale.”
The MSU extension report encourages those purchasing plants to take time to inspect before buying. The best way to prevent spreading crape myrtle bark scale is to not buy or plant infested crape myrtles.
Crape myrtle bark scale is part of a group of insects called felt scales. It spreads in close range by wind or birds or flying insects transferring crawlers. Long-range dispersal happens through human transport of infested plants.
Dr. Gary Bachman from the MSU extension service advises those who have found crape myrtle bark scale to begin by using a soft brush to scrub the trunk and limbs to remove females, crawlers and eggs.
According to Bachman, this process helps the insecticides to be more effective. It also will remove a lot of the black, sooty mold.
When treating the tree, he suggests applying a systemic insecticide to the plant root zone during the months of May and July. The insecticides will take several weeks to work as the chemicals spread through the plant.
