Mealybugs are difficult to control, especially when they are feeding on plant roots. In addition the waxy coating on eggs and the insects help protect them from insecticides. If there are only a few on a houseplant, crush them or carefully wipe them off the plant. If theinfestation is severe, it is much easier to destroy the plant and get a new one. Also most mealy bugs get on house plants because the plants were taken outside for the summer or sometimes just for a day or two. Minimize mealy bugs on houseplants by NEVER taking the plants outside. Use suggested insecticides according to all label directions and precautions.
Outdoors on hawthorn, mealybugs are commonly more noticeable than harmful. Large infestations can cause leaves to turn brown and young stems to die. Usually, treatment is not needed because large infestations are uncommon.