Like most insects, they are looking for a warm place to stay for the winter.
Most people know that this is a problem we didn’t start having until several years ago. The reason is these exotic ladybugs were imported from Asia beginning in 1978 to help control aphids in pecan trees as well as suppressing pests in a wide variety of plants including vegetables, apples, cotton, corn, cereal crops, pine trees and ornamental plants. For example, they are helpful in keeping aphids off roses and crape myrtles in your yard during the summer.
Not only do they eat aphids, but they are some of the most successful predators of other harmful insects, namely mealybugs, scale, mites, and other soft bodied insects. Ladybugs are predators in both the immature and adult stages.
Many organic gardeners have ordered containers of ladybugs and then released them in their garden to try and help control the above mentioned harmful insects. The only problem is the ladybugs don’t seem to stick around. I guess if you could get your neighbors to release them they might fly over to your yard.
While ladybugs are our best buddy for plants in the landscape, these exotic species like to winter inside in large groups. They are attracted to light colored structures with sunny south and southwest exposures. There they will congregate outside windows, doors, walls and porch decks. If they find the tiniest cracks of a structure, they will move inside. Other than our homes, they like to congregate in outbuildings or gather in hollow trees and logs.
You may notice that every time we have warm spells during the fall and winter months, out they come again looking for a place to go.
When ladybugs are getting inside your home, that means you have cracks and/or leaks, which also means you are losing heat. The best way to stop them is to caulk the cracks around window frames or small holes in the exterior wall. Install tight fitting door sweeps and rubber seal around the garage door.
It has been my experience that if you have a really old house, it is practically impossible to seal all the small cracks. My office is an old 1800s house and we have plenty of them inside here. I find most of them dead in the window sills. They can’t live long in low humidity.
You can use insecticides to help reduce the beetle numbers from entering your home. Spray around the outside doors and windows with a pyrethroid insecticide. Pyrethroids can be a number of different brand names and active ingredients. Examples are cyfluthrin (Bayer Advanced Home Pest Control), bifenthrin (Ortho Home Defense), lamda-cyhalothrin (Spectracide Bug Stop). Basically any “home” type insecticide that ends with “thrin” is in the pyrethroid family and would work well.
Most of these come ready mixed and are labeled for indoor use too. So you could also spray inside around doors and windows and in areas they congregate. Depending on which product you use, one application may last until the weather warms up for good next spring.
If you don’t want to use insecticides, there is an alternative that seems to work. A few years ago I heard about a lady in the Augusta area where the beetles were congregating inside her house and had left some orange stain. When she cleaned the area with soap and water the beetles didn’t congregate there anymore. Other people have tried this and it seems to work well. Lady beetles emit pheromones (odors) that attract other beetles, so one can surmise that you are wiping away the pheromones. You can also use soap and water to wipe the outside around the doors and windows.
There is a black light trap that you can buy to catch the beetles indoors or you can make your own. One you can buy is free standing and can sit on a table or the floor. It can be purchased from Southeastern Insectaries, southeasterninsectaries.com.
Once inside though, ladybugs will not cause any harm to humans. They do not sting or cause any human diseases, nor do they feed on wood, clothing, furniture, human food or reproduce inside the home. They can nip you with their mouthparts, causing a little pinch, but they are harmless and cannot break the skin.
You can remove the beetles with a broom and dust pan or the vacuum cleaner with a crevice tool attachment. The standard horticultural advice is to take them outside and release them (a good distance from any house), but usually most of them are dead, especially if you try to get them out of a vacuum cleaner bag.
You must be careful if you handle ladybugs or pick them off walls because this stresses them and stressed beetles secrete an orange substance (insect blood) from the joints in their legs and this can stain the walls and the fabrics of your furniture.
Ladybugs inside are a seasonal problem. Once the weather warms up for good in the spring, they will begin looking to stay outside until the weather begins to turn cold next fall.
Reach Sid Mullis, the director of the University of Georgia Extension Service office for Richmond County, at (706) 821-2349 or firstname.lastname@example.org.