Origin:
Appears to be native to the Southeast United States.
Biology:
This scale has been found infesting hundreds of different ornamental plants, with ferns a particular favored host, and greenhouses commonly infested. It is the most common scale insect infesting interior plants, where they are found along stems, veins of leaves, and on developing buds and flowers. In heavy infestations entire areas of the stems may be covered, and this level of feeding can seriously reduce plant health, causing wilting but less often the actual death of the plant. Large quantities of honeydew support the growth of black sooty mold. The scale completes development to the adult stage in 60 days or less, and in warm conditions there can be up to 7 generations in a year. All stages may be present simultaneously in greenhouses. Males and females mate, and the female then gives birth to living young. These mobile crawlers then emerge from under the female’s wax shell and move to new areas of the plant.
Identification:
Adult females have an oval, flattened wax shell about 3 to 4 mm long. Color begins as light yellow or green and turns brown with age, often with darker mottling on it. The mobile crawlers have visible legs and are yellow in color.
Characteristicts Important to Control:
On perennial outdoor plants dormant or summer oils may be effective, as well as contact insecticides applied when the first instar crawlers are present. An IGR applied when crawlers are present also may be effective. Indoor plants must be treated much more cautiously, with a product labeled for this use. Several applications should be expected due to the overlapping generations of the scales and the presence of crawlers at any time of the year.
