As the owner of a house in Butler County, I am concerned about the giant numbers of ladybugs in my garden and on my house. Why are there so many? They sometimes cover the house outside and even get in the house. Are they harmful? How do I decrease their numbers?
The Gardener’s Answer
Hi, Kirk: It sounds like you are dealing with an infestation of Asian lady beetles (Harmonia axyridis). These beetles, commonly known as ladybugs, are not necessarily harmful but in large numbers can be a nuisance. They were introduced from Asia to feed on unwanted insects and more were brought over unintentionally. No matter how they got here, they are beneficial in terms of controlling destructive insects, but overwhelming in large numbers. They cannot survive our winters, so during the fall they start searching for somewhere warm to stay for a few months. Sealing your windows, doorframes, and other spaces they can enter will help the situation. It may take a couple seasons, but if there is nowhere for them to survive they cannot reproduce, therefore reducing the population. They typically live two to three years. When these beetles feel threatened, they will secrete a foul-smelling yellowish liquid, so swatting them may not be the best idea. A vacuum is recommended for getting rid of them indoors. You might consider hiring a professional if you feel they are a real problem. The following site is a publication from the entomology department at the University of Kentucky: www.ca.uky.edu/entomology/entfacts/ef416.asp