Ladybugs, or lady beetles, are beneficial insects to gardeners because they are predators of garden pests like aphids and spider mites. However, you need to keep the ladybugs under control, as come autumn, the adult beetles will try to enter your home to find shelter until the spring. If they gain entry, they can be a pest all winter. They do no direct harm, but some believe they contribute to indoor allergies and they can also be very messy. They do not feed on or damage anything in the house, do not carry diseases, or sting, but they will crawl over the walls, windows and light fixtures, making quite a mess.
Ladybugs prefer to cluster on the sides of houses and other buildings, eventually working their way into the edifice through small cracks or crevices, or natural breaks in the window panes, door jams or foundations, as the temperatures decrease. Once inside the building, ladybugs hibernate, until the first warm days of late winter or early spring, when they seem to come to life again and begin crawling about in order to get outside.
Prevention is the best control method you can apply. Several steps can be taken in order to prevent ladybugs from moving into your house during autumn. It is important to avoid giving them the opportunity of entering your home, and you can do this by spraying the exterior walls during the fall months with deterrents. Once ladybugs have become established in the home, the treatment options are limited. The easiest way to remove ladybugs, once they are indoors, is with a vacuum cleaner. Don’t try to sweep or otherwise agitate them, because when stressed, ladybugs release a yellow, smelly substance that can cause stains.
Another way of preventing them from entering your home, is by sealing them out by caulking cracks and utility service openings, by fixing broken window screens and door jams, by plugging cracks in the foundation or roof. The best results are usually obtained by using high-quality silicone or silicone-latex caulk, but if you have particularly large holes in the foundation, you may want to use mortar or cement. Ladybugs leave behind trails of pheromones, which attract them to the same sites year after year, so you need to make sure they have no means of getting in when they try this next time.
Tips for preventing ladybugs from entering you house and solutions for getting rid of them
- Install screens on doors, windows, and porches, and make sure they are properly sealed;
- Seal siding (if you have it) around potential entrances such as pipes or air vents;
- As the weather gets colder, you may also want to consider temporarily blocking your vents with a fine wire mesh;
- Apply weather stripping, as it is one of the easiest ways to seal off a gap at the bottom of a door;
- Use a pyrethroid-based aerosol insecticide on the external walls of your house, especially those facing south and southwest, from the ground up and as high as you can;
- Line the immediate perimeter of your house with diatomaceous earth, which will absorb lipids from the ladybugs, causing death by dehydration; if you have children or pets, it is recommended that you use food grade diatomaceous earth, seeing as this is safer, but you should still ensure that neither come in contact with it;
- Planting mums around the entrance of your home and around your windows may repel ladybugs, seeing as they do not like them;
- Working on the same principle as above, you can use bay leaves and cloves; the ladybugs hate the smell of them, and they will avoid it; lemon, citrus, or citronella-scented candles can be also used for the same purpose;
- Spray camphor and menthol around areas you suspect are infested, as these will drive the ladybugs away without killing them. As ladybugs are sensitive to strong odours, they will choose to move away from areas that reek of camphor and menthol;
- While light traps offer limited help, setting one or two up in a dark attic or dark basement can attract and trap a few of the ladybugs hiding out in these locations. These traps will only take care of a fraction of the problem as they are effective only on ladybugs living in confined, dark spaces;
- Make a trap using soap and water, as the reflecting water will attract the ladybugs and then the soapy water will trap them, when they fly into the bowl;
- Sprinkle boric acid in the areas where you see ladybugs traveling. The effect it has on the ladybugs that come in direct contact with it is that they end up getting dehydrated and finally die;
- Consider exterior building colour as a last resort as it is said that light colours and contrasting colours are more appealing to ladybugs. Painting or siding your house with dark colours could, theoretically, cause fewer ladybugs to come visit, but don’t count on this as being the only action you need to take to prevent ladybugs from entering your home.
Once the ladybugs find their way out of your home, they’re gone for good. Typically, that’s springtime, and of course, several will simply die inside your home while waiting for spring. Other than leaving their unsightly carcasses behind, they’re harmless, but should you be dealing with a serious infestation, make sure you follow these instructions on how to get rid of ladybugs.