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
Economic Importance
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
Hosts
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.
Caution:
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.
