CHARLESTON, W.Va. -- The non-native Asian lady beetles are coming! The non-native Asian lady beetles are coming! The non-native Asian lady beetles are coming!
On a recent trip to Pennsylvania, we discovered several dead lady beetle bodies in an unused closet of my brother's lake house. It reminded me that we need to prepare for the autumn onslaught.
First, let's identify the pest for what it is and what it isn't: It's not the beneficial, native ladybug that invades your home in the fall. These good bugs usually spend the winter in leaf litter and are a great organic way to control aphids and other slow-moving pests. A single ladybug can consume up to 50 to 60 aphids per day, but will also eat a variety of other insects and larvae including scales, mealy bugs, leaf hoppers, mites and various types of soft-bodied insects. They search all day from dawn to dusk for food.
It's the Asian lady beetles that come in every crack and crevasse, leaving their stinky, staining bodies around for us to remove. There have been cases where they've clogged pipes and vents -- they head for warm spots and settle in. Unlike roaches, moths or fleas, the beetles are just pests and they don't reproduce indoors or harm wood, food or clothing.
Because they don't wear little black or white hats, how do we tell the good guys from the bad? The Asian lady beetle has a distinctive black, M-shaped marking behind its head.
According to the University of Kentucky College of Agriculture, "During the 1960s to 1990s, the U.S. Department of Agriculture attempted to establish the Asian lady beetle to control agricultural pests, especially of pecans and apples. Large numbers of the beetles were released in several states including Georgia, South Carolina, Louisiana, Mississippi, California, Washington, Pennsylvania, Connecticut and Maryland. Some scientists believe that current infestations in the U.S. originated not from these intentional releases, but from beetles accidentally transported into New Orleans on a freighter from Japan."
As autumn approaches, the adult beetles leave their summer feeding sites in yards, fields and forests for protected places to spend the winter. Unfortunately, they often pick homes and buildings. Swarms of lady beetles typically try to get into buildings in September though November, depending on locale and weather conditions. Beetle flights are heaviest on sunny days following a period of cooler weather, when temperatures return to at least the mid-60s. Consequently, most flight activity occurs in the afternoon and may vary in intensity from one day to the next.
Why talk about these pests now? Because it's the perfect time to shore up your home before they try to get in. They can crawl in through the smallest cracks, so seal windows with caulk, add weather stripping around doors and place fine screens over any openings into the attic and soffits. Clean yard tools and ornaments as you store them for the winter to make sure there are no ladybugs coming inside along with them.