Origin:
Believed to be native to Europe, but now present in all tropical and many temperate regions of the world.
Biology:
The scale has a wide host range that includes avocado, bamboo, banana, orchids, palms, guava, mango, oleander, rose, sugarcane, and many other trees and shrubs. When present in heavy numbers the scales cause yellowing of leaves, deformation of plant parts, death of outer twigs and entire plants. The entire life cycle in tropical regions may take only 30 days. The crawler stage does not feed, but wanders to soft foliage and within a few hours or a few days becomes sessile and begins creating a wax shell. As they molt the previous skin (called the exuvium) is pressed into the growing wax shell, forming a characteristic dot at the center. There may be several generations each year, with all stages present at any one time. The major population growth is during the warm months.
Identification:
Closely related to the Greedy scale, but differs by the yellow exuvium compared with the brown exuvium of the Greedy scale. Also similar to the soft scales Olive Scale and Oleander Scale, but can be distinguished by the more conical shape to the wax shell. If the wax shell is removed the scale insect itself is yellow.
Characteristicts Important to Control:
For ornamentals dormant or summer oils may be effective in killing the scales, as well as contact insecticides applied when the first instar crawlers are present. An IGR applied when crawlers are present also may be effective. A systemic applied to the soil can also provide effectiveness in killing the feeding scales. For food-bearing trees a registered insecticide needs to be used as a topical treatment.
