Aphids cause the leaves to be coated with sticky honeydew. Spray with malathion, rotenone or Sevin. The insects can also be dislodged with high pressure water spray from the garden hose.
Leaf miners cause brown areas on the leaves. No chemical controls are listed.
Privet thrips cause the foliage to become grayish and take on a dusty appearance. Use sprays of malathion, rotenone or Sevin.
Scales of several types may infest privet. Examine the stems closely--the insects are not easily seen. Overwintering stages are controlled with dormant oil sprays applied in the spring. Crawlers can be controlled with sprays of Sevin. The preferred method of control is a combination of regular inspection to detect the infestation early, then spray with dormant oil.
Mites cause the foliage to turn yellowish or stippled. Heavy infestations form fine webbing on the leaves.