If something unusual happens in the county, especially if it is related to pests, the chances are pretty good that someone in my office will get a phone call. So we were not too surprised last fall to receive quite a few phone calls about a rather uncommon pest. We know this pest is in the area, and since it is time for it to begin to annoy people, this may be a good time for me to warn you and to share some information about Asian lady beetles.

The Asian lady beetle was not even known in North Carolina until about seven years ago. It appeared first in the western piedmont and mountain areas of the state. Then two years ago, we began to see this pest in the Raleigh area and the eastern parts of the state. Last year was the first time we had received complaints from local homeowners about this pest.

The Asian lady beetle is a close relative of the common lady beetle we all know and have learned to recognize. Like the common lady beetle, both the adult and nymph stages of the insect feed on aphids. Because they eat so many aphids, they are considered a very beneficial insect, and all efforts should be made to protect them as much as possible.

The annoying characteristic about the Asian lady beetle is that when the weather begins to turn cool in the fall, it starts to look for an attractive and comfortable hiding place where it can spend the winter.

The locations that are most attractive to them tend to be the sunny sides of buildings, which tend to be the warmest. They are especially attracted to light-colored buildings. Of course, this doesn't mean that people with dark-colored siding, brick, or log homes are immune to the lady beetle assault.

The problem is that if the building is attractive to one beetle, it is probably also attractive to other beetles in the area. The problem gets worse, because these beetles tend to congregate by the thousands. And the problem gets even worse when the building they choose is your home.

Once the beetles choose a suitable site, they use chemical cues to locate the specific crevice they want to use to enter the structure. The source of these chemical cues may be beetle feces from the previous winter, the odor of beetles that died at the site, or an attractant pheromone. These factors may help to explain why beetles seem to pick the same sites every year.

Since so many beetles may be present in a home, it may seem to the homeowner that the beetles are reproducing in the house. This is not true. During the summer the beetles prey on aphids that are abundant on many of the plants and flowers in our landscapes. The lady beetles lay their eggs on these same plants. The lady beetles do not feed or reproduce indoors. They are simply heeding nature's call to escape potentially harsh and fatal winter weather. Also, the beetles do not cause structural damage. However, they will cause a yellow-brown stain that is difficult to remove if they are disturbed or squished.

Since these beetles are beneficial, it is highly recommended that homeowners do not try to kill them with pesticides. Trying to treat outdoor areas would be too expensive, and you simply can't treat enough areas safely and effectively to prevent the beetles from finding access points into the house.

If these beetles do find their way into your home, the best method of control is still the old vacuum cleaner. One potential problem with vacuuming up the beetles is the odor from dead or squished beetles inside the vacuum cleaner bags, particularly if the bags are not changed frequently. A remedy to this is to insert a woman's knee-high stocking into the vacuum's extension hose and then secure it with a rubber band before putting the attachment back on. This allows you to trap the beetles inside the stocking, which then conveniently closes up at the end with the rubber band and can be removed. You can also simply tie a knot in the end of the stocking.

Once you capture the beetles, you have a couple of options. If you like to be friendly to the environment, you can keep the beetles in the refrigerator over the winter and then release them in your garden next spring to help control aphids. An alternative is to toss your trapped beetles into the garbage.

If strange, red beetles with black spots invade your home, at least you will know what they are. Hopefully, you will know not to try to kill them but to try to manage them so they will remain in the area to help control aphids next summer.

E-mail address: Everett_Davis@ncsu.edu

Mailing Address:
P. O. Box 2280
Lumberton, NC 28359-2280

Phone: 910-671-3276
Fax: 910-671-6278

Date Created 10/24/01