What is the most common insect pest on azaleas?

The azalea lace bug [Stephanitis pyrioides] is the most common insect problem on azaleas. It sucks the sap from the leaves. The leaf tops are left with white or yellow and green speckles. The undersides have hard, shiny black droplets of excrement.

The culprits may be the bug in either one of two stages. One may be the spiny, wingless larvae. The other may be the brownish adult insects with large, clear, lacy wings.