False oleander scale, an armored scale, was first described in California from palms taken in quarantine from China. It was first found in Florida at Meade Gardens, Winter Park, Orange County, by J. R. Springer on sweetbay (Magnolia virginiana L.) in 1942. In 1953, G. B. Merrill reported the distribution in Florida as Orange and Leon counties. It is now widespread in Florida, Georgia and Alabama, and probably occurs in all of the Gulf States.
The female armor is pear-shaped, shiny white, and 2 to 3 mm long. The exuviae are terminal and yellowish brown. The size of the female scale may vary with the host. For example, it is slightly smaller on palmetto than on aucuba. The male armor is elongate, snow-white, feebly tricarinate, and about 1 mm long. The male exuviae are terminal with a faint yellowish tinge. Males usually occur in clusters on the leaf.
Females of the false oleander scale, Pseudaulacaspis cockerelli (Cooley)
Photograph by: University of Florid
False oleander scale has become an economic pest of many of the major ornamental plants found in Florida commercial nurseries. The rapid distribution throughout Florida can be attributed to the movement of infested nursery stock.
The scale tends to confine itself to feeding on foliage and rarely attacks tender shoots or fruit. Its feeding causes chlorotic spots that are visible on the upper leaf surface. These spots are usually several times larger than the scale. Heavy infestations cause the entire leaf to turn yellow and drop prematurely.
Cluster of male false oleander scales, Pseudaulacaspis cockerelli (Cooley),
on leaf of bird-of-paradise. A few female present.
Photograph by: Division of Plant Industry
False oleander scale is probably not a good name as this species has over 100 plant species recorded as hosts in Florida (Dekle 1976). These include: Magonolia grandiflora, magnolia; M. virginiana, sweetbay; Aucuba japonica; Strelitzia spp, bird-of- paradise: Hedera helix; Cornus florida, flowering dogwood; Taxus spp.; Nerium oleander, oleander; Michelia figo, banana shrub; Elaesgnus spp.; and Sabal mexicana, a palmetto (Merrill 1953, Johnson 1991). This scale is also an important pest of Mangifera indica, mango (Crane 1994).
- All life stages of the scale may be found throughout the year.
- Visually inspect both leaf surfaces.
- If necessary for identification, submit adult female specimens attached to the host plant in a plastic bag or envelope to either DPI or your local county Cooperative Extension Service office.
Scales, especially armored scales are very difficult to control when mature. Examine plants for live scales by crushing the wax cover. Dead scales do not fall from plants. Select pesticides that have the least effect upon other non-target organisms. For established infestations, apply a second application in two weeks. Horticultural oils are often effective and relatively safe on beneficial organisms. Time sprays to coincide with the crawler stage which is most susceptible to insecticides.
Insecticide mode of action and formulation are important in insecticidal control of scales because armor covers and protects all stages but the crawler and the adult male. Contact insecticides target the crawler stage; systemics target adult females and feeding nymphs. Contact of organophosphates, carbamate and pyrethroid insecticides can reduce but not eradicate Cockerell scale. Since the scale has natural enemies, care must be taken to conserve these. Populations of other pests, such as spiraling white fly, coconut scale, and ti scale, many rise if their natural enemies are affected by chemical control of the Cockerell scale. Spraying should be determined by presence of scales in the fields rather than by the calendar. Scales are best detected by regularly inspecting all areas of the fields for white, pearshaped armor. When detected, directing spray at hotspots rather than uninfested areas is economical, conserves natural enemies, and delay pesticide resistance.
Pesticides used improperly can be injurious to human beings, animals, and plants. Follow the directions and heed all precautions on labels. Store pesticides in original containers under lock and key out of the reach of children and animals and away from food and feed.
Apply pesticides so that they do not endanger humans, livestock, crops, beneficial insects, fish, and wildlife. Do not apply pesticides where there is danger of drift when honey bees or other pollinating insects are visiting plants, or in ways that may contaminate water or leave illegal residues.
Avoid prolonged inhalation of pesticide sprays or dusts, wear protective clothing and equipment, if specified on the label.
If your hands become contaminated with a pesticide, do not eat or drink until you have washed. In case a pesticide is swallowed or gets in the eyes, follow the first aid treatment given on the label, and get prompt medical attention. If a pesticide is spilled on your skin or clothing remove clothing immediately and wash skin thoroughly.
NOTE: Some States have restrictions on the use of certain pesticides. Check your State and local regulations. Also, because registrations of pesticides are under constant review by the U.S. Environmental Protection Agency, consult your local forest pathologist, county agriculture agent, or State extension specialist to be sure the intended use is still registered.