Cacti and succulents have to be resilient to survive in some of the hottest and driest places on earth. Little gets past their sharp spines and tough skin, except two tiny insects that can do a lot of damage.
Mealybugs and scale are particularly attracted to cacti and succulents. They can injure and even kill them by feeding on their juice.
Mealybugs attack all parts of a plant, above and below ground, but are usually found on leaves and stems. A plant will be covered with what looks like sticky white cotton, and up close, you can see small, white oval bugs.
Mealybugs can be tough to completely eradicate. Scale insects cover themselves with hard oval, tan or brown shells. They congregate on leaves and stems, and multiply quickly.
Treat Cacti and Succulents for Mealybugs and Scale:
- Wear gloves before handling cacti, or use bunched-up newspaper or paper towels to hold the plant.
- Spray water hard enough to dislodge the insects, but not so hard as to damage the plant.
- Nick scale off with a fingernail or tweezers.
- Spray the plant with insecticidal soap, neem oil or horticultural oil. Follow directions on the package, as improper use can damage the plant.
- Wipe mealybugs or scale with a cotton swab dipped in a solution of 50 percent rubbing alcohol and 50 percent water.
- Large infestations may need treatment with a systemic insecticide. This is a last resort. Avoid insecticides containing imidacloprid, which can harm pollinators. Consider whether to remove and replace the plant instead.