Ladybird beetles (Ladybugs)
By John Cambridge, Phd Candidate
Beneficial insects have been used to suppress pest populations in agriculture for thousands of years. The Chinese were one of the first civilizations to use this technique by promoting ant colonies in there orchards. Today, beneficial insects are still widely used but we tend to favor other species in place of ants. Ladybird beetles (family coccinellidea, also called ladybugs) are one such type of insect that growers have put to great use. Both the larva and adult forms are veracious predators and often feed on a wide variety of small pests. One such ladybug is Harmonia axyridis. This insect naturally inhabits Eastern Asia and was intentionally introduced into the US to control aphids. This insect has proved very successful in controlling aphid pests in many areas but its presence is potentially causing negative impacts for native lady bird beetles. Also this insect is starting to get attention from homeowners as it is the main ladybug that people find in their homes over the winter. To deal with H. axyridis in your home, you should first find where they are coming in. Generally they will come in through gaps around the flashing, windows, doors, and any external vents. Your main focus should be minimizing these entrance points. While doing this, keep in mind that you don’t want to completely seal your house as that will lead to mold in the walls. Once unnecessary gaps are filled, treat the remaining entrances with a pesticide that has a long residual (so you don’t have to reapply it ever couple days). When doing a pesticide application, you must make sure you aren’t endangering those close by; parents of small children should READ THE ENTIRE LABLE CARFULLY before dumping chemicals around their house! I like to recommend using something almost entirely non-harmful like diatomaceous earth. Sprinkle some in the gaps and most small insects that walks over it will get very small cuts, which will in turn cause them to desiccate and die. This method will not stop every insect coming into your house but it provides enough pest suppression that instead of being grossed out by ladybugs all throughout winter, you can get excited about seeing one land on your desk once every couple weeks. If this is still to frequent a sighting for you, consider using a stronger pesticide (try Permethrin). In the end, when dealing with ladybugs in your home, it’s important to remember that these insects provide a valuable service for us and without them, we would likely have more insects in our homes and gardens and they would not be as pretty. So don’t go to hard them, after all…everyone you see is 6 days good luck!