Scale insects are serious pests on camellias in Alabama. Scale insects pierce plant tissue, sucking out plant juices and reducing the vitality of the plants. Heavy infestations can result in unsightly plants, fewer and smaller blooms, twig die-back, and eventually plant death.
 

Identification Tea scale is the most widely distributed and most damaging insect pest on camellias. Tea scales feed underneath leaves. This usually causes the upper leaf surface to become yellow-splotched. When infestations are heavy, cottony filaments can be seen hanging from the leaves. A waxy covering develops over each scale as it grows. The females develop hard brown covers about 1/10 inch long. The males develop fragile white covers that are usually a little smaller than those of the females. Females lay eggs for several weeks and eggs hatch continuously. This results in overlapping generations almost year-round. Control A major problem with tea scale control is that often damage has been done before the scale infestation is noticed. This means that in spite of control efforts, the damaged leaves will often be retained by the plant for at least a season or more. A 2- or 3-year program may be necessary to bring the infestation to a manageable level. Add a spreader-sticker to your spray mixture and be sure to direct the spray to the underside of leaves to obtain better contact of the insecticide with the scale insects.

Under surface of camellia leaf infested with tea scale (enlarged). Top surface of camellia leaf damaged by tea scale.

Beginning in April, use one of the following insecticides two or three times about 2 weeks apart. Fall treatment may also be needed if infestations are heavy.
 

Insecticidal oils may be effective in control of light to moderate tea scale infestations. Some oils can be used in the spring prior to or after blooming and in the fall prior to blooming. Highly purified oils such as SunSpray can be used during the growing season. Check the label for use instructions.

*Do not use dimethoate on rotunda or burford hollies.

Euonymus Scale

Euonymus scale is a common insect pest on euonymus in Alabama. Other host plants include boxwood, holly, ligustrum, and pachysandra.

Like other scale insects, euonymus scales damage plants by piercing the tissue and sucking out the sap. Yellow or white spots on the leaves result from this feeding. Heavy infestations cause leaves to yellow and drop and may eventually kill the plant if not controlled.
 

Identification

The euonymus scale develops a waxy cover over its body as it grows. Mature female scale covers are about 1/16 inch long and look like brown oyster shells. The females are found mainly on stems and sometimes on leaves. The male covers are usually slightly smaller than the females and are more elongated. The males are white with three longitudinal ridges. Males are found mostly on the underside of leaves and on lower branches of the plant.

In Alabama, the euonymus scale goes through the winter as fertilized adult females. The eggs are laid in early spring and usually hatch during late March. The newly hatched "crawlers" move to other parts of the plant, settle, and begin to develop waxy coverings. There are three generations a year in Alabama. Crawlers emerge in March, June, and August.

Control

Certain varieties of euonymus are less susceptible to attack by euonymus scale. Research at Auburn University indicates that spreading euonymus (Euonymus kiautcbovica), dwarf winged euonymus (Euonymus alatus compacta), and winter creeper euonymus (Euonymusfortunei acutus) are more resistant to euonymus scale than some other varieties.

Be sure that euonymus plants are free from scale when you buy them. Examine plants regularly in order to control scales before extensive damage to plants occurs. Cut back heavily infested plants and spray new growth with a recommended insecticide.

For control of euonymus scale on euonymus, spray one of the following during crawler emergence periods and repeat at 10-day intervals for three treatments:
 

A dormant oil spray (5 tablespoons per gallon of water) used before new plant growth begins may also help control euonymus scale. Check labels for temperature restrictions for use of oils once growth begins.

The pesticide rates in this publication are recommended only if they are registered with the Environmental Protection Agency and the Alabama Department of Agriculture and Industries. If a registration is changed or cancelled, the rate listed here is no longer recommended. Before you apply any pesticide, check with your county Extension agent for the latest information.

Trade names are used only to give specific information. The Alabama Cooperative Extension System does not endorse or guarantee any product and does not recommend one product instead of another that might be similar.

For more information, contact your county Extension office. Look in your telephone directory under your county's name to find the number.