Oak trees are frequently the target of insect infestation. In Austin, Texas, this infestation can range from disease contracted through the bark of the oak, such as oak wilt, or from insect damage to the tree through leaf damage. This is otherwise known as defoliation. Because of the innate value of oaks, especially to a home landscape, it is important to know to which insects oak leaf defoliation is attributed, the effects of defoliation, and how it can be prevented.
Although insects, including caterpillars, are responsible for defoliation of trees, the primary culprits responsible for the defoliation of various species of oaks within various regions belong to the moth family.
Croesia semipurpurana is a member of the moth family and is thought to be perhaps one of the most serious of all defoliators. In fact, this species has contributed to the decline of scarlet and red oaks, and has been found to be a defoliator anywhere from the east coast as far west as Texas in the United States. This species is thought to be the primary link between defoliation and tree mortality.
Archips semiferana is another member of the moth family and is also known as a leaf roller. This species is responsible for the mortality of white and chestnut oaks, particularly in areas of higher elevations.
Gypsy moths, or Porthetria dispar L., are also defoliators. They are primarily responsible for the defoliation of oaks in the eastern United States. It is documented that the gypsy moths were responsible for a significant amount of damage to oaks in the northeastern United States in the late 1960s and early 1970s.
The effects of defoliation are quite logical. The defoliators feed on the leaves of oaks. Consequently, the leaves are integral to the overall sustainability of the tree. Because the leaves are vital to the conduction of photosynthesis, the lack of them greatly reduces the tree’s ability to provide itself with the nourishment it needs to remain viable and flourish.
Affected oaks that remain untreated and undergo successive seasons of defoliation are most likely to suffer mortality. The effects of oak mortality not only include the overall decrease, or possible extinction, of oaks, but also economic impacts as well. Oaks used to supply lumber for construction projects or used to beautify home, commercial, or municipal landscapes may decrease in availability and, as an economic result, therefore increase consumer costs associated with purchases or maintenance.
If you have concerns that your landscaping oaks may be affected by defoliators, perhaps through the observation of leaf tatters, contact an Austin tree trimming professional, who can carefully examine the branches for the presence of defoliating insects and assist in treatment.
In order to preserve your oaks, it is important to address any defoliators that may be present. However, it is equally important to treat the problem with care so that the solution doesn’t become a problem. Applying pesticides must be done with caution so as not to destroy the healthy, unaffected segments of the tree. Contact an Austin tree care professional to assist you with carefully treating the tree, killing any existing defoliators while still maintaining the overall vitality of the oak.
About the Author: Andrew Johnson is the owner of Central Texas Tree Care, a leading provider of Austin tree service in Central Texas. Certified ISA Austin arborist services including: tree trimming, tree removal, tree care and oak wilt treatment. For more information on Austin tree service, please visit https://centraltexastr.wpengine.com.