Description and Life History

Female mealybugs are wingless and lay several hundred eggs in a cottony mass.  Some species give birth to living young.  Newly hatched nymphs (immatures) are flattened and oval-shaped, with smooth, yellow bodies.  Soon after they begin to feed, a white waxy coating begins to form over their bodies, and they resemble adults except for their smaller size.  Mature females are about 1/6 to 1/4 inch long.  When the males are almost grown, they form a loose white cocoon.  The males emerge as small, two-winged insects that do not feed.  They fly around and mate with the females.  Indoors or in a greenhouse, a generation can be completed in about a month.
 

Long-tailed mealybug.  Note waxy, "mealy" appearance.

Damage And Host Plants

Mealybugs feed by piercing plant tissue with their needle-like mouthparts and sucking out the plant juice.  Infested plants may be discolored and wilted.  Like other scale insects, mealybugs produce honeydew.  Plants may be so sticky from honeydew and so disfigured by the sooty mold that often grows in honeydew that they must be discarded.
Mealybugs feed on a wide variety of plants.  In greenhouses they are well known pests of coleus, fern, begonia, and geraniums.  Mealybugs are most often found at the base of stems or petioles.
 

Long-tailed mealybugs on leaf. Note honeydew and discoloration.

Control

Indoor Plants.  Examine plants before you buy them to be sure pests are not present.  Plants kept outside during warm weather can become infested; examine them carefully before moving them inside. A few mealybugs can be removed by hand or with a cotton swab dipped in rubbing alcohol.  Check the plant in a week and repeat if necessary.
There are only a few pesticides available for use indoors on houseplants.  Be sure that if you use a pesticide indoors, the label indicates such use.
If the plant is heavily infested, it may be too far gone to save.  Get rid of it and start over.  If the lower portions of the plant are damaged, take a cutting and start over.

Outdoor Plants.  Be sure to use pesticides only on plants listed on the label in order to avoid possible plant damage.  Repeat treatment in 2 weeks if needed. According to the 2001 Alabama Pest Management Handbook, the following chemicals are available to homeowners for mealybug control.
 

The pesticide rates in this publication are recommended only if they are registered with the Environmental Protection Agency and the Alabama Department of Agriculture and Industries. If a registration is changed or cancelled, the rate listed here is no longer recommended. Before you apply any pesticide, check with your county Extension agent for the latest information.

Trade names are used only to give specific information. The Alabama Cooperative Extension System does not endorse or guarantee any product and does not recommend one product instead of another that might be similar.

For more information, contact your county Extension office. Look in your telephone directory under your county's name to find the number.