Euonymus scale begin life as eggs produced by the female under her protective covering. The newly hatched scale are mobile for a brief period, during which they are known as crawlers. The crawlers move a short distance from their birth site and then attach their mouthparts permanently to the euonymus plant. Immature males develop a white, waxy protective covering over their bodies, while the females develop a brown covering similar in appearance to an oyster's shell. The females remain permanently attached to the plant.
Males remain immobile until they molt into the adult stage.
Adult males live only 1 day, during which time they can fly and mate with mature females. Euonymus scale pass through the winter months in the form of mature females and immature males. Euonymus scale have one to three generations per year, depending on the climate. Warmer climates are associated with more generations. Because of the increased number of generations and increased winter survival in warmer parts of the country, euonymus scale tend to be more serious a pest there than in cooler climates.