Of all the pests we deal with in Interiorscape, nothing bugs me more than Mealy (har!).
photo courtesy of University Of MD College of Agriculture
Mealybug is one of the most pervasive pests we deal with in interior landscaping. It appears as white, q-tip looking type cottony blemishes on otherwise healthy leaves. These little miscreants suck the juices from the plant leaves and cause yellowing, browning, and dying leaves. If left untreated, it can quickly ravage the plant and render it in need of replacement.
Worse, the severely weakened plant is much more susceptible to other pests such as scale and mites as a result. It’s like I tell people: The mealybug throws a party on your plant and invites all its pesky friends over for a buffet.
Plants in your home are not immune to mealy, but it thrives in offices and commercial buildings because of the poor air quality, limited airflow, and hot, dry conditions. In large commercial indoor plantings it’s a nightmare: It can quickly spread from plant to plant and before you know it you have a full scale infestation.
Treatment is usually two fold: For a quick “knockback” we use a combination of rubbing alchohol and water, 50/50, that kills the mealy on when it’s sprayed on the leaves. Another great natural pesticide is dishwashing detergent and water. Yes, plain old liquid dishwashing detergent. Mix a half a teaspoon or so in water, get it nice and foamy, and spray it on the affected areas. It smothers the mealybug, and as long as you don’t overdo it, is perfectly fine for the plant. It can dry on the leaves–it doesn’t need to be washed off. Routine application of this over a period of a week or two when the mealy is noticeable should eventually eliminate it.
For long term control Merit or some other systemic pesticide is best–these are introduced into the soil with watering and the plant absorbs them through it’s root structure and it becomes inherent in the leaves and shoots of the plant providing protection for up to 6 months or more.
To keep Mealy from forming on your houseplants, use a humidifier in your house in the winter. Spraying the leaves periodically with water will help the plant as well. Generally healthy plants don’t develop mealy, but nature can sometimes find a way, and with a little help from humans we can rid the plant of these pests.