The Black Olive Scale (Saissetia oleae) is a common scale insect that feeds on olive trees and other ornamental plants. These insects attach themselves to plant stems and leaves where they extract sap using piercing mouthparts.
Identification
Adult scales appear as small, dome-shaped bumps on plant surfaces. They are dark brown or black in color and typically measure about 1/8 inch long. Because they remain stationary on plants, they are often mistaken for plant growths rather than insects.
Distribution and Habitat
Black olive scale insects occur worldwide and are especially common in Mediterranean climates where olive trees are grown. They may also infest ornamental plants in residential landscapes.
Life Cycle and Behavior
The life cycle includes egg, crawler, and adult stages. The crawler stage is mobile and spreads to new feeding sites on the plant before settling and forming the protective scale covering.
Pest Status
Black olive scale insects are plant pests because they weaken plants by feeding on sap. They also produce honeydew, which promotes the growth of sooty mold.
Prevention
- Inspect plants regularly.
- Encourage beneficial insects such as lady beetles.
- Prune heavily infested branches.
Control
Control may include horticultural oils, insecticidal soaps, and biological control agents.