Megacopta cribraria, also known as the kudzu bug, is once again moving from its preferred host in search of protected sites where it will spend the winter. Once on the move, the adult bugs are attracted to light-colored surfaces – landing on people, vehicles, and buildings. They are a nuisance pest for those living in our urban and suburban areas. This mass migration results in complaints and inquiries to pest control operators, Cooperative Extension offices, and the media.
The cool temperatures we have been experiencing coupled with the dying back of kudzu, its preferred host, are likely causes of the mass migration. The same phenomenon was seen in the late fall of 2009 and 2010 when the bugs moved from kudzu in search of sites in which they will spend the winter in a mostly inactive state. In the spring these adults emerge, lay eggs on sprouting kudzu, and begin building large populations of the insect. These may also infest soybeans and a number of other legumes found in the Georgia landscape (including beans and peas in home vegetable gardens).
Unfortunately, there have not been any significant developments in controlling this nuisance pest in suburban and urban environments. Research on its control will continue. We are hopeful that the large numbers of these insects we currently see reflect a “colonization effect” of these recent invaders from Asia. If so, we will likely see kudzu bugs reach an ecological equilibrium in which their numbers are not as high as we see now. Until then there are a few tips to consider:
• Seal, with caulk or screen, all cracks around windows and doors, and make sure there are no gaps under doors and around soffits. Install doorsweeps on all outside doors, if necessary.
• Kudzu bugs should not be killed inside. They should be vacuumed if found inside to prevent the noxious odor/exudate from penetrating and perhaps, staining indoor surfaces.
• At this time of year (mid-October to mid-November), kudzu bugs are most active in the afternoon as temperatures warm up later in the day. As such, plan outdoor activities in the morning, if possible, or move activities indoors.
• Kudzu bugs can be killed with pyrethroid insecticides applied directly to the insects, e.g., while resting on outside walls. However, given the peak of flight activity currently occurring, homeowners should expect significant re-invasion within a day or so. If you use an insecticide, read and follow the product’s label (it’s the law), and never use a pyrethroid insecticide in an area where it might contaminate water as these insecticides are very toxic to fish and other aquatic life. No traps have been commercialized (and shown to be effective) in attracting and killing large numbers of kudzu bugs. Effective chemical attractants have not yet been identified.
• The flight will subside, based on our experience, in late November, but the bugs will once again become active, and mildly troublesome in the spring of 2012 as they awake from their winter slumber. In light of this, if kudzu can be removed from the property, it is recommended that this be done in order to eliminate potential problems once again in October 2012.