The scale is a highly modified sucking insect, and its outer covering thickens after it feeds giving it added protection. Four days later, adults emerge. The life cycle takes about 40 days, depending on temperature. This insect is difficult to manage. The five distinct stages of the life cycle all differ in their tolerances to insecticides.
Eggs are resistant to most insecticides as are the scale and pupal stages.
The crawler is quite susceptible to insecticides, especially contact materials and the adults are also susceptible to fumigant and contact materials. All stages, however, can coexist. A single application of a particular insecticide only affects the susceptible stages present at the time of treatment or shortly thereafter. Other stages will survive and ultimately reproduce again continuing the cycle. Therefore, when sprays are recommended, they are usually applied at 5 day intervals covering the 40 day period that it takes for completion of the life cycle.