Mealybugs are often found on the leaves, stems and flower buds of your plants. If a plant is severely infested, consider pruning and removing heavily infested plant parts to prevent the spread of mealybugs to healthier sections of the plant. One indicator of the pests is the development of sooty mold on leaves of plants.
—LSU AgCenter/Heather Kirk-Ballard
Get It Growing: White stuff on plants caused by mealybugs
If you’ve noticed the presence of white, fluffy, cotton-like formations on your plants, chances are you’ve encountered one of the most common garden pests: mealybugs.