The Big 3 Tree Pests in Oklahoma City area

Date posted:

While we view trees as objects of beauty and grandeur, many things view trees as a tasty meal. Over the years we have treated thousands of trees in central Oklahoma, whether it's the old Oaks in Oklahoma City, the elegant Elms in Edmond, or the Maples in Moore, we have noticed there are some common offenders amongst us. Depending on the time of year and the tree species, we can usually tell you what is ailing your tree before an actual site visit or description. So without further ado, let's outline a quick summary of the usual suspects and some management options.

1.) Bagworm: The larvae arrives in Spring, usually in late April or May and they begin feeding on the plant material immediately. The larvae becomes noticeable once the bags start emerging, usually beginning around 1/4 inch long. In the Oklahoma City area Bagworms are far more likely to be found on Junipers, Cypress, and Arborvitae. They have been documented on a 128 species throughout the United States though. Probably one of our most common trees is the Eastern Red Cedar (which is a Juniper rather than a Cedar) and is arguably the favorite meal of Bagworms around here. Heavily infested Junipers and Cypress can be completely defoliated causing the death of the tree, deciduous trees however are rarely affected for more than a season.

         If practical, hand picking the bagworms off the tree can be quite effective as long as all are removed. Make sure all bags are picked off the tree by spring before the overwintering eggs hatch.  If handpicking is impractical either the homeowner or a Certified Arborist may deem chemical control the best option. A yearly application in early to mid June is generally the best timing to catch most of the eggs hatching and provides season long control.

2.) Fall Webworms: Often confused with Bagworms, Webworms can single handedly turn a beautiful tree into an eyesore within a few short weeks. While they rarely completely defoliate the tree, they can greatly weaken the tree making it more susceptible to borers and disease. The earlier the damage the worse off the tree will be. Their webs are most commonly observed in late summer and early fall, hence their name, the Fall Webworm. In Central Oklahoma they are commonly found in Pecans, Black Walnuts, Hickory, and Persimmons. They have been documented in many other species however depending on the severity of that years outbreak. In outbreak years they can emerge as early as late May and June though. Their are two types of Fall Webworm in Oklahoma, the black headed and the red headed. The main difference between the two is that the black headed has three generations per year and the red headed has two generations, making both very difficult to control

       Control of the Fall Webworm can be a difficult task due to the size of the trees they are generally found on and the multiple generations per year. If you decide chemical control needs to be applied a Certified Arborist with the proper equipment should be consulted. Spraying for the Fall Webworm is usually not the best choice for management due to the large possibility of overspray on such large trees and the inability to penetrate the webbing. A systemic insecticide can be a viable option, but comes at a higher cost.

3.) Scale: I view scale as one of central Oklahoma's largest silent killers. They often go years without being noticed and often are mistaken for something else due to not looking like the typical insect. There are several different types of Scale in our area. They can be grouped loosely into two categories, soft scale and armored scale. Armored Scales do not produce honeydew while Soft Scale produces copious amounts of the annoying honeydew. Scale can infect multitudes of different trees, shrubs, and even groundcover slowly sucking the life out of the plant. The Scale feeds through leaf and bark tissue slowly stealing the vital nutrients the trees need to have to survive. To make matters worse the Soft Scal produces honeydew a byproduct which in turn can cause the fungus sooty mold. Scale, like the Fall Webworm, has several generations per year making it difficult to control. All in all, Scale is a real thorn in the side.

      To thicken the plot more, a new species of Scale has introduced itself into Central Oklahoma we have noticed this year. Crape Myrtle Bark Scale was first found in Texas in 2004 and has slowly progressed our way. It is of great concern because Crape Myrtles have always been the go to plant for ease of care being relatively pest free. It is an easy Scale to identify as its really the only scale to infest Crape Myrtles. Adult females are felt-like white or gray encrustations that stick to crape myrtle parts ranging from small twigs to large trunks. When crushed, these scales exude pink “blood”-like liquid. The Sooty Mold byproduct is often the first thing noticed and can lead to misdiagnoses.

     Scale can be a real trick to fully control. Managing Scale insects on plants is done best throughout the year, every year. The key is to manage scale populations and keep them as low as possible. Frequent and timely Tree & Shrub Care treatments can keep Scale numbers from getting out of control and damage occurring. Creating a Plant Health Care program customized to your landscape’s unique challenges will make sure the right amount, right kind, and right-timed treatments occur.