Mealybugs

Facts, Identification & Control

Scientific Name

Family Pseudococcidae

Appearance

Mealybugs are very small, soft-bodied, oval-shaped insects that are covered with a white, powdery wax coating. In addition, many mealybug species have projections extending from their body, giving them the appearance of having many legs on the side and rear of the body. When seen on plants, they look like very small spots of cotton. Mealybugs move slowly, but when they find a suitable location on the plant, they often become immobile and form clusters on the plant.

Behavior, Diet & Habits

Mealybugs are plant feeders and will infest most parts of their host plant. They normally are located on the underside of plant leaves and stems, and populate many outdoor plants such annuals, bushes and shrubs. Mealybugs will heavily infest almost any plants in greenhouses, homes or businesses. They feed by forcing their needle-like piercing mouthparts into the plant and use a sucking action to remove the plant juices. Mealybugs attract ants by excreting honeydew, a sticky, sweet substance that the ants feed on. Plants infested with mealybugs usually have leaves that turn yellow and wilt, and if the infestation is not eliminated, the plant may eventually die.

More Information

Mealybug control for commercial greenhouse and crop growers costs millions of dollars each year. For the homeowner, mealybug control may not be expensive, but can be very time consuming since success depends upon a very careful inspection process. The easiest solution for the homeowner may simply be tossing out infested plants. If disposal is not an option, the homeowner can “quarantine” plants for 10-14 days as a way to ensure infested plants are not brought home. Also, there are many types of insecticidal soaps that will control mealybugs via direct application. Since ants may move mealybugs from one plant to another, an insecticide may be needed for ant control. If using insecticides, always follow the product label and seek the advice and expertise of your pest management professional before using any insecticide products.

Treatment of Mealybugs
If you suspect you have mealybugs infesting your plants, contact your pest management professional for an inspection and to prepare an integrated mealybug treatment plan to effectively and efficiently resolve the problem.

The complexity of mealybug treatment is situational. Depending on the number of plants that are infested and the location of the infested plants, the appropriate treatment plan may range from very simple prevention and control to somewhat more complex and widespread treatment techniques. Some of the important methods of mealybug treatment may include the following:

Education and Damage Recognition
Mealybugs feed by sucking plant juices which weakens the plant and causes the plant’s leaves to turn yellow, wilt and drop. The insects also produce honeydew, a sticky substance that increases mold growth on plants and attracts feeding ants.

If the mealybug infestation is not eliminated, the plant will probably die.

Damage Prevention
One of the easiest ways to manage mealybug infestations is to prevent introduction of infested plants into the house’s interior. The homeowner can carefully inspect any plants that are purchased before bringing them home for interior use or exterior landscape planting. If the plants appear to be free of mealybugs, it is a good idea to “quarantine” the plants for about two weeks. Another method to prevent mealybug damage is to cut out or cull infested leaves or stems so there is no opportunity for mealybugs to further expand the population on the infested plant. As a last resort, the most efficient method to prevent damage can be to simply dispose of infested plants to keep mealybugs from spreading to other, non-infested plants.

If a minor mealybug infestation is discovered, treating the infested plant(s) may require using alcohol-soaked cotton swabs to treat the insects; removing mealybugs by exposing infested plants to running water; and/or washing the plants with soapy water.

If the mealybug infestation is widespread, the treatment plan may require a product to treat not only mealybugs, but also to treat ants that are feeding on the honeydew produced by the mealybugs. This is important since ants protect mealybugs from predators and may move mealybugs from one plant to another, thus increasing the number of infested plants. If the treatment plan requires using a product, it is usually best to let your pest management professional apply it since his/her experience and knowledge ensures the product’s labeled-use directions are followed and adhered to strictly.