Tea scale a pest for camellias

Q: My Camellia leaves are turning yellow and there is a white cottony looking mass on the underside of the leaves. What is it?

A: The tea scale, Fiorinia theae, is probably the most common and damaging pest of camellias and dwarf burford hollies. It is also a pest of many other ornamental and fruiting crops.

The tea scale was first discovered in 1900 on tea plants collected in India, thus its common name. It was probably introduced into the United States when the demand for ornamental camellias resulted in plants being imported from Asia. By 1908, tea scale was already a pest on camellias in South Carolina. The tea scale is found primarily in the southeast but has spread west to Texas and California.

The tea scale's development depends upon the climate where it lives. Here in Florida, the tea scale remains active throughout the year. The adult immobile female lays her eggs under her protective armor.

Females lay eggs for several weeks and eggs hatch continuously. This results in overlapping generations almost yearround. Within 10 days, the first nymph hatches and is called the "crawler" stage. The crawler leaves the protection of the mother's armor and moves about the plant looking for soft tissue into which they insert their piercing-sucking mouthparts.

The crawler is the only stage in which the infestation is actively spread. This is also the easiest stage in which to kill the tea scale.