Bark Scale and the Crepe Myrtle: Understanding the Threat and How to Protect Your Trees

Crepe myrtles are beloved for their beautiful blooms and easy care, making them a popular choice for gardeners across the United States. However, in recent years, these trees have come under threat from a tiny pest known as bark scale. Here, we’ll take a closer look at this pest and explore how to protect your crepe myrtles from its damage.

What is Bark Scale?

Bark scale is caused by an aphid that feeds on the sap of trees, particularly crepe myrtles, leaving a black fungal infection in its wake. These pests are tiny, measuring only a few millimeters in length, but they can cause significant damage to trees over time. Bark scale infestations can lead to leaf loss, branch dieback, and in severe cases, tree death [1].

Identifying Bark Scale Infestations

One of the first signs of a bark scale infestation is the presence of white or grayish scales on the bark of a crepe myrtle. These scales are often arranged in rows and resemble small bumps on the trunk and branches. As the infestation progresses, the tree may start to show signs of decline, such as thinning foliage, stunted growth, and the development of sooty mold on the bark and leaves [2].

Protecting Your Crepe Myrtle

Photo by Junaid Khan on Unsplash

If you suspect that your crepe myrtle is infested with bark scale, there are several steps you can take to protect your tree. One of the most effective methods is to use a horticultural oil spray, which suffocates the pests by coating them in oil. This treatment should be applied in the fall, winter, or early spring before new growth appears [3].

In addition to horticultural oil, there are other natural methods for controlling bark scale, including releasing predatory insects such as ladybugs or lacewings. These beneficial insects feed on the bark scale and can help keep populations under control [4].

Preventing future infestations is also key to protecting your crepe myrtle. Regular pruning and maintenance can help keep the tree healthy and less susceptible to pests and disease. Additionally, avoiding the use of harsh chemicals and pesticides in your garden can help preserve the natural balance of beneficial insects and predators that keep pests in check [5].

In conclusion, bark scale is a serious threat to crepe myrtles and other trees, but with proper identification and treatment, it is possible to protect your trees and keep them healthy and beautiful for years to come. By taking a natural and holistic approach to pest management, you can help preserve the health and vitality of your garden ecosystem.

FAQ Questions:

What is bark scale?

Bark scale is a type of insect that feeds on the sap of trees, particularly crepe myrtles. These pests are tiny, measuring only a few millimeters in length, but they can cause significant damage to trees over time.

What are the signs of bark scale infestation?

The first signs of bark scale infestation are the presence of white or grayish scales on the bark of a crepe myrtle. These scales are often arranged in rows and resemble small bumps on the trunk and branches. As the infestation progresses, the tree may start to show signs of decline, such as thinning foliage, stunted growth, and the development of sooty mold on the bark and leaves.

How do I protect my crepe myrtle from bark scale?

To protect your crepe myrtle from bark scale, you can use a horticultural oil spray, which suffocates the pests by coating them in oil. Releasing predatory insects such as ladybugs or lacewings is another natural method for controlling bark scale. Additionally, regular pruning and maintenance can help keep the tree healthy and less susceptible to pests and disease.

What is the best treatment for bark scale?

The best treatment for bark scale is a horticultural oil spray, which suffocates the pests by coating them in oil. This treatment should be applied in the fall, winter, or early spring before new growth appears.

Can I prevent bark scale infestations?

Preventing future infestations is key to protecting your crepe myrtle. Regular pruning and maintenance can help keep the tree healthy and less susceptible to pests and disease. Additionally, avoiding the use of harsh chemicals and pesticides in your garden can help preserve the natural balance of beneficial insects and predators that keep pests in check.

References:

Fitzpatrick, S.M., and Forth, H. (2020). The Basics of Bark Scale. The University of Georgia, Extension Bulletin 1506. https://extension.uga.edu/publications/detail.html?number=B1506.

USDA Forest Service. (n.d.). Bark Scale: An Emerging Pest of Crape Myrtle. https://www.fs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb5327678.pdf.

Texas A&M AgriLife Extension. (n.d.). Bark Scale Management in Ornamental Plants. https://agrilifeextension.tamu.edu/library/landscaping/bark-scale-management-in-ornamental-plants/.

Landers, A., Smith, D., and Cloyd, R. (2015). Lacewings, Ladybugs, and Parasitic Wasps for Bark Scale Control. Kansas State University, Research and Extension. https://www.ksre.k-state.edu/dotasset/73a6078c-d7c5-414e-b9f1-31f6b4e6de