Crepe myrtle bark scale

Crepe myrtle bark scale (Acanthococcus lagerstroemiae) is a destructive scale insect belonging to the family Eriococcidae within the order Hemiptera. Originally identified in Asia, this pest has become a significant concern for arborists and gardeners globally, particularly due to its specialized impact on ornamental landscapes and specific fruit-bearing trees.

The primary host for this insect is the crepe myrtle (*Lagerstroemia* spp.), but it is also known to infest other plant species including pomegranate, persimmon, elm, and various fruit trees. The infestation often goes unnoticed until the characteristic white felt-like covers become visible on the trunks, limbs, and even smaller twigs of the host plants.

The life cycle of the bark scale is complex, involving several nymphal stages known as crawlers. These small, mobile crawlers are the primary means of infestation, as they move along the bark to find suitable feeding sites. Once a site is selected, they insert their mouthparts to feed on plant phloem, eventually maturing into sessile adults that continue to reproduce.

Damage caused by this pest is twofold: direct feeding damage and indirect secondary impacts. Heavy infestations lead to significant loss of plant vigor, reduced flowering, and stunted growth. Furthermore, the excess sugar excreted by the insects promotes the growth of black sooty mold.

• Significant reduction in plant aesthetic quality.
• Secondary infections of branches due to mold coverage.
• Increased susceptibility to environmental stressors.

Integrated Pest Management (IPM) is essential for effective control. Cultural practices, such as pruning heavily infested branches and maintaining plant health through proper irrigation, provide a solid foundation. Chemical control relies on the application of systemic insecticides, particularly soil drenches or bark sprays applied when crawlers are most active, ensuring that chemical interventions are timed correctly to break the reproductive cycle.