Cypress bark scale

Systematic position: The cypress bark scale (Ehrhornia cupressi) belongs to the order Hemiptera and the family Kermesidae. This sucking insect is a specialized pest that primarily targets members of the Cupressaceae family, often causing significant aesthetic and physiological damage to trees in urban and natural landscapes.

Host plants: The primary host range includes various species of Cupressus, Juniperus, and Thuja. The pest thrives on weakened or stressed plants, particularly those subjected to poor irrigation, soil compaction, or inappropriate environmental conditions, leading to localized outbreaks in plantations and ornamental gardens.

Biology and life cycle: The life cycle of Ehrhornia cupressi includes eggs, crawlers (the first instar stage), and adults. Females are largely sedentary and secrete waxy substances that act as protective covers. The crawler stage is the most critical for dispersal, as these tiny nymphs move across the plant tissue to find suitable feeding sites on branches, where they then anchor and begin to sap the tree’s nutrients.

Damage and harm: Feeding damage results in general tree decline, which manifests as foliage yellowing, branch dieback, and stunted growth. The pest excretes honeydew, a sugary substance that serves as a substrate for sooty mold growth. This mold covers the needles in a black layer, which blocks photosynthesis and significantly reduces the overall health and vigor of the host plant.

Protection measures: Integrated pest management (IPM) is essential for effective control:

• Regular monitoring of twigs and branches for the presence of waxy scales or honeydew.
• Application of systemic insecticides specifically timed to target the mobile crawler stage.
• Pruning and destroying heavily infested branches to reduce local population pressure.
• Implementing proper horticultural practices to improve plant resistance, such as adequate irrigation.
• Dormant season treatments using horticultural oils to suffocate overwintering stages on the bark.