Kudzu Bugs (AGAIN)

We've had two reports (Scotland County and Union County) that kudzu bugs are moving out of soybean fields and congregating on structures, including homes and school buses. This move out of host plants was anticipated but perhaps not this soon. As to why it's happening now is pure speculation, but favorable weather, particularly early this year, likely contributed to this early exodus as the adult bugs head into reproductive diapause.

The kudzu bug's fall movement indoors is very similar to what we've experienced since the 1990’s with the Asian lady beetle. The major difference between the two insects is that the Asian lady beetle is actually beneficial as a biological control agent, chomping down on aphids and other plant-feeding insects. By contrast, the kudzu bug's primary food source (aside from kudzu) happens to be field crops, such as soybeans, where they can significantly impact yield. So, this pest packs a double-whammy for North Carolinians. 

The kudzu bugs’ fondness of soybeans is one reason why we could see significant numbers of them invading homes and other buildings, even in rural areas. In more urban areas, there are plenty of other hosts such as wisteria and privet. The insects are quite mobile; they are capable of catching rides on wind currents, automobiles, trucks, trains and planes. This helps explain why this pest has managed to spread in from north-central Georgia and through most of South Carolina, North Carolina, and Virginia (plus west into Mississippi) in just about 3 years time. 

At this point, we still do not have anything new to report in terms of recommendations to homeowners and businesses as to how they might address this problem. Kudzu bugs are attracted to light-colored surfaces but that certainly doesn't mean that brick buildings or those with dark-colored siding will escape the bug invasion. While most folks want shortcuts and easy solutions, there simply aren't any when it comes to the kudzu bug. The emphasis still has to be on exclusion because chemical control is still only partially effective and relies primarily on directly targeting the insects that are aggregating on surfaces. Preventive sprays are not recommended - because they simply won't be durable enough to last the weeks during which these insects will be actively seeking overwintering sites. If the situation is severe and you decide that pesticides are warranted, you can choose any of the common exterior insecticides labeled for application to buildings. Use targeted treatments of critical areas: windows and door frames, and some soffits. Be sure to read and follow all label directions carefully. Many of the exterior insecticides contain pyrethroid and new label changes restrict where and how the product may be applied.

If large numbers of kudzu bugs make it indoors, simply vacuum them up. The use of pesticides indoors is not warranted and will be largely ineffective in this case.

Again, we stress exclusion - plugging those holes that the bugs can use to enter homes and
businesses - as job #1.

For more information about kudzu bugs, please visit:
http://www.ces.ncsu.edu/depts/ent/notes/Urban/kudzubug.htm