It’s the chilly time of year when gardeners look ahead to spring—starting cool-season vegetables, finishing pruning chores, and finally paying attention to long-neglected houseplants. Taking a closer look at indoor plants can sometimes reveal more than dust, and one common winter surprise is mealybugs.
How to Recognize Mealybugs
- Appear as white, cottony masses tucked into:
- Leaf axils
- Stem joints
- Growing tips
- Undersides of leaves
- Often accompanied by:
- Sticky residue (honeydew)
- Black sooty mold
- Ant activity
Plants Commonly Affected
- Outdoors: gardenia, chrysanthemum, geranium, gladiolus, grape, apple, peach, pear, plum, maples, yews
- Indoors: orchids, African violets, begonias, ferns, palms, and other houseplants
What They Are and Why They’re a Problem
- Mealybugs are related to aphids and scale insects
- They feed by sucking plant sap, which can cause:
- Reduced vigor
- Leaf yellowing and drop
- Loss of buds and flowers
- Honeydew encourages ants and supports sooty mold growth
Life Cycle and Behavior
- Soft-bodied, grayish insects (0.05–0.2 inch long)
- Females are wingless and covered with waxy filaments
- Crawlers (young stage) are small, mobile, and easily spread between plants
- They hide in soil, on roots, and under pot rims
- Multiple generations can occur indoors each year
Management (Least-Toxic First)
- Isolate infested plants immediately
- Rinse plants with a strong stream of water
- Dab insects with 70% isopropyl alcohol using a cotton swab or soft brush
- Repeat treatments to catch newly hatched crawlers
- Use insecticidal soap or horticultural oil if needed
- Clean pots and treat the soil surface
- Control ants to prevent reinfestation
Early detection and persistence are key to keeping mealybugs from taking over indoor plants.
Click here for more information about managing mealybugs.