They're fuzzy and soft and sucking the life out of my plant. Mealybugs are attacking my orchid.

Female mealybugs are small, oval insects that cover themselves with white waxy threads. This waxy coat protects them from many predators and pesticides. They also use the threads to create a cozy nest for the hundreds of eggs they lay. Immature males resemble females, but adult males are winged and lack the sucking mouthparts of the females.

A female can lay up to 600 eggs during her lifetime. As the eggs hatch, the emerging "crawlers" disperse to suitable feeding sites on the host plant or onto new plants. When they reach their destination, they insert their stylet (sucking tube) into the plant and take up permanent residence.

Even though the stylet is tiny and threadlike, the damage these insects can inflict is significant. They are often found along leaf veins or where leaves join the stem. As they suck sap from the plant, it becomes weakened. Leaves turn yellow and drop off. If left unchecked, the plant will eventually succumb to the damage. In the process, the mealybug also will excrete honeydew, a sugary liquid. In an indoor setting, this honeydew can drop onto lower leaves as well as plant stands and even the flooring below forming a sticky film.

To cut through the waxy coating and eradicate these bugs, common rubbing alcohol can be used on most plants. A solution of 10 percent rubbing alcohol and 90 percent water is all that is needed. For small infestations a cotton swab dipped in the solution can be dabbed on the fuzzy masses. A spray of the mixture can be used for heavier infestations. Insecticidal soap also is an option.

Some plants are sensitive to an alcohol mixture or insecticidal soap. They can cause leaf burn on some plants, so be sure to test a small area before you use either of these methods. If using an insecticidal soap, be sure to follow all label directions.

Since mealybugs and most other common houseplant pests have short life cycles and prolific reproduction potential, regularly check your houseplants. Control procedures might need to be repeated weekly until the infestation is eliminated. You also might want to isolate an infected plant while implementing controls, as it can serve as a source for infecting nearby plants.

Heavily infested plants should be pruned to remove the affected area or destroyed altogether.

For more information on mealybugs and their control, check out Factsheet No. 5.595 at the Colorado State University Extension website,
