Question of the Week – Number 1: November 22, 2018
“What are these white insects, and how can I control them?”
Those are mealybugs, and they’re some of the worst pests you can get on your houseplants. They are a soft-bodied type of scale insect.
This photo from the University of Wisconsin Extension Service shows a serious outbreak of mealybugs. It’s difficult to eliminate them when they’ve built up this level of population.
There are insecticides that are labeled for use in killing scales, but it’s best to treat your plants out on a shaded patio or in the garage. Let the spray run down into the leaf axils, as nymphs hide in those tight spaces.
For plants that have large leaves, many people prefer to use cotton swabs or cotton balls dipped in rubbing alcohol to rub the adults off and to kill the nymphs.
Mealybugs will spread to other plants, so early control is critical. You’ll probably need to treat for them three or four times to bring them under control. If a plant seems overwhelmed by them, it’s usually better to discard it rather than trying to save it.