False oleander scale is one of the most serious pests affecting ornamentals in southern regions such as Florida, appearing as numerous white specks or larger, blurry spots (clusters of these insects) on plant leaves. The individual spots are 2 to 3 mm in diameter and are usually more common on upper leaf surfaces. Often, a yellow spot develops in the leaf tissue where the insects are feeding. In large numbers, these sucking insects can remove enough plant sap to cause defoliation on sensitive species.
This scale attacks the foliage of cycads, gardenia, English ivy, magnolia, bischofia, camellia, oleander, palmetto, and 100+ other plant species.
This is an armored scale with a hard outer covering much like a shell. The female’s covering is pear-shaped and shiny white. The male’s covering is elongated with three faint ridges, has the consistency of StyrofoamTM, and is approximately 1 mm long. The female deposits eggs under its shell. The first instar nymphs, often referred to as “crawlers,” emerge, disperse for a short distance, and then settle by anchoring into the plant tissue with their sucking, stylet-like mouthparts. They do not move to another location once they settle. A generation can be completed in five weeks.
Target insecticide applications when new leaves start to expand in the spring. At least three treatments are usually needed at 5 to 6-week intervals. Another option is to use a systemic insecticide applied to the soil or injected into the trunk. Even though the scale insects may die, they do not fall off the plant, because their shells are affixed to the leaves. To confirm that the application has been effective, scrape the shell. If it is dry and flaky, the scale is dead.