by David Moore
Manager of Technical Services and Board Certified Entomologist
with contributions by Eric Smith, PhD, BCE
Last year about this time in a Facebook Q&A (9/30/12), I warned that the Kudzu bugs were coming. Well, they’re here and in large numbers in some locations. In the spring, they feed and develop on kudzu vines which typically grow along roadsides and that originally were planted for erosion control. This time of year as the weather cools, Kudzu bugs almost daily gather in clusters on the sunny sides of homes and other buildings and try to find a way inside.
In the last couple of weeks, the Dodson office in Lynchburg, VA had a large commercial customer experiencing Kudzu bugs invading their manufacturing plant, the Roanoke, VA office received a call from a school that had Kudzu bugs clustering on their outside walls, etc. The school asked for a no-pesticide solution if possible. As a temporary quick fix, what I suggested is given below. But first, let’s do a quick review of this new pest.
WHAT ARE THESE BUGS?
They are another pest introduced from Southeast Asia that was first found in 2009 in the Athens, GA area. They are both a nuisance by overwintering in structures like multicolored Asian lady beetles, brown marmorated stink bugs, boxelder bugs, and cluster flies, but they are also a serious agricultural pest. Matter-of-fact, in 2012 they destroyed about 30% of the soybean crop in the southeastern US. They are both good hitchhikers and good fliers.
WHAT DO THEY LOOK LIKE?
Kudzu bugs are 1/6″-1/4″ long, somewhat square-like with rounded corners, and their rear end looks as if it were cut off at an angle (truncated). They are olive-green to tan with brown speckles in color (see photo)
WHAT IS THEIR CURRENT DISTRIBUTION?
From being found in GA in 2009, they have spread rapidly south, west, and especially north. By August of 2013, they had spread northward almost
completely through all of the states all the way to much of northern VA, to
southern MD and southern DE, westward through LA and
north up to southern and eastern TN, and southward through northern FL. Recently our offices in Danville, Roanoke, Lynchburg, and Big Island, VA have received calls.
WHAT DO THEY DO?
In the spring, they feed primarily on Kudzu, but also on a wide variety of other legumes including other bean species, as well as wisteria and some vetches. They then move to feeding on soybeans about midsummer each year.
WHAT SHOULD YOU DO?
It’s too late to prevent their entrance into your home by sealing its exterior; this should be done next May. If you would attempt to seal them out now, you would actually trap many of them inside your walls which can result in other pest problems later on such as dermestid/carpet beetles feeding on the dead insect bodies and then wandering into living areas.
WHAT CAN YOU DO RIGHT NOW?
- Isolate individual rooms. From/on the inside, seal the rooms on the warm side of your house (south and adjoining east and/or west walls) so that these bugs cannot enter your living space; see last month’s Blog “Overwintering Pests: Once the invasion has begun” on the Dodson Bros. website for details.
- What about the bugs themselves? The quick fix but only a temporary fix is to remove them with a vacuum. Be sure to use an inexpensive dedicated shop-type vacuum because the rough handling will often cause them to release their stinky odor.
- To minimize this problem, place a knee-high nylon stocking in the hose just behind the nozzle attachment (see photo). When the nylon gets full of bugs and/or immediately after use, take off the attachment nozzle, remove the nylon, tie it off, and seal it in a plastic bag and then put it in an outside trash can. After use, put the vacuum outside in a cool garage or shed to reduce any odor being given off. (See photos)
- Check your southern walls daily and vacuum whenever Kudzu bugs are seen in numbers. Do this until the days cease to reach about 50°F. Then anytime until spring when we have warm weather (days above about 60°F in sunny areas), go out and check your walls for Kudzu bugs during the warm part of the day. Vacuum when you find clusters of Kudzu bugs.