Ladybugs (AKA lady beetles) have long had a good reputation and have been highly regarded as being beneficial for gardens and the environment. In fact, ladybugs have become a sign of good luck for many people. However, a relatively new invasive species called the Asian lady beetle has begun to make people question this reputation. Along with the benefits, they also bring many problems that can frustrate homeowners.
Benefits of Lady Beetles
Lady beetles have long been touted as a great way to control bugs in gardens. They love to chomp down on pests like aphids, spider mites, and mealy bugs. They do so well at controlling these types of soft-bodied insects that people regularly buy and release ladybugs into their garden for this purpose. Native ladybugs do not bite, spread disease, or cause damage, so they became fast favorites. In the early part of the twentieth century, Asian lady beetles were introduced to North America to help with aphid control. They did a great job and were especially helpful for pecan growers. Unfortunately, they brought with them a series of problems that have called their benefits into question.
Problems with Asian Lady Beetles
Asian lady beetles are aphid eating machines, just like their native cousins, but they also tend to be more aggressive, may bite if handled, produce a foul smell, and can be harmful to dogs. The biggest annoyance for most people is the fact that, unlike native lady beetles that remain outdoors, Asian lady beetles like to enter homes and buildings to overwinter. When fall rolls around, you will often see huge clusters of Asian lady beetles on the sides of sunny walls. Researchers believe that they may produce an aggregation pheromone that helps to draw in other lady beetles in the area. Once on the walls, they will try to find a way inside through cracks, crevices, open windows or doors, or unscreened vents or chimneys. Indoors, they will overwinter in wall voids, crawl spaces, etc. and can produce smelly secretions that can stain walls and furniture.
How to Tell the Difference
Asian lady beetles and native lady beetles look very similar. They are approximately the same size (¼ inch) and can be the same colors, including yellow, orange, red, and black. Luckily, there is a distinguishing feature that can help you determine if the ladybugs around your property are native or invasive. Simply look at the section behind the head. If that area is all black, you have native ladybugs that will likely not cause any problems. If, however, the section right behind the head is white with a black “M” shape, you are dealing with Asian lady beetles.
Asian Lady Beetle Control
Although Asian lady beetles can be frustrating, their benefits may outweigh their problems. If you can deal with the fall clustering and take preventive measures to keep them out of your house, you may want to put up with the nuisance. If you are having trouble keeping them out of your house and are frustrated, Harris home pest control can help. Harris Asian Lady Beetle and Box Elder Bug Killer can be sprayed on south and west facing walls to prevent them from congregating and entering your home. For more information, check out Ladybugs and Asian Lady Beetles: The Ultimate Guide.