Learn how to identify and control crape myrtle bark scale, a common pest, with effective strategies.
What is Crape Myrtle Bark Scale?
Crape Myrtle Bark Scale (CMBS) is a problematic pest that attacks crape myrtles, one of the most popular ornamental trees in landscapes. Initially identified in the United States in 2004, it has since spread to various parts of the country, causing concern for gardeners and landscapers. This pest is an invasive species known scientifically as Eriococcus lagerstroemiae, and it is unique because it specifically targets the crape myrtle, leading to aesthetic damage and sometimes even health decline of affected trees.
Identification of Crape Myrtle Bark Scale
Identifying CMBS early is crucial to effectively managing an infestation. The bark scale appears primarily as white or gray felt-like encrustations on the bark of crape myrtles. These can show up anywhere on the plant, from the trunk to the twigs. Infested trees often exhibit black sooty mold due to the excretion of honeydew by the scale insects, which can coat the leaves, branches, and surrounding surfaces.
Furthermore, close inspection may reveal tiny pink to gray insects under the felt-like covering. During heavy infestations, these scales may spread to the leaves’ underside. Gardeners might also notice a reduction in flowering and overall vigor as the tree’s resources are usurped by the feeding scales.
Life Cycle of the Crape Myrtle Bark Scale
Understanding the life cycle of CMBS is essential for implementing effective control strategies. These insects overwinter as nymphs on the tree’s bark. In late spring to early summer, they begin to produce eggs that are hidden beneath the protective waxy cover. Each female can produce up to 100 to 300 eggs that hatch into crawlers. These crawlers disperse to new locations on the tree or are spread by wind, birds, and other animals to new crape myrtles, where they settle and begin to feed, starting the cycle anew.
Chemical Control Measures
Chemical treatments can be effective in controlling CMBS when used appropriately. Systemic insecticides, which are absorbed by the tree and transferred throughout its tissue, can be very effective. Products containing the active ingredients imidacloprid or dinotefuran can be applied as soil drenches or injections. These can provide long-lasting control. It is crucial, however, to follow the label instructions carefully to avoid harming beneficial insects and to minimize environmental impact.
Biological Control Measures
Biological control involves using natural predators to maintain or decrease pest populations. Lady beetles, lacewings, and parasitic wasps all are natural predators of CMBS. Encouraging these beneficial insects can be done by planting diverse plant species that provide nectar and pollen. Avoiding broad-spectrum insecticides also helps preserve these helpful species.
Cultural Control and Prevention
Cultural practices play an important role in mitigating the spread and impact of CMBS. Proper plant care, including appropriate watering, fertilizing, and pruning, can help maintain a tree’s health and its ability to withstand and recover from an infestation. Additionally, inspecting new crape myrtle plants thoroughly before introducing them to your landscape can prevent bringing in infested material.
Integrated Pest Management (IPM)
An IPM approach combines cultural, biological, and chemical methods to provide effective and environmentally sustainable control of CMBS. Monitoring for early detection, using targeted chemical treatments when necessary, and promoting beneficial species are all part of a rounded IPM strategy.
Conclusion
Crape Myrtle Bark Scale poses a significant threat to the beauty and health of crape myrtle trees. However, with proper identification, understanding of the pest’s life cycle, and the implementation of an integrated management approach, gardeners and landscapers can control CMBS and keep their trees thriving. Regular monitoring and being proactive in management practices are the keys to protecting these beloved trees from the detrimental effects of this invasive scale.
5280 Tree Care