If you live in the Southeast United States, you’ve likely become acquainted with the relatively new invading kudzu bug, which was brought here from Asia in 2009. Homeowners say they can’t seem to get rid of these bothersome insects, which can frequently be found on their homes and cars during the fall and spring months. You can sweep them off with brooms, you can suck them up with vacuums, but the very last thing you want to do is crush them because they’ll stain a surface and they have a pretty obnoxious odor.
Homeowners in cities like Atlanta, Charlotte, and Raleigh, see swarms of these bugs in the spring and again in the fall, but during the summer they settle down in fields of kudzu and soybean plants. It’s in the soybean plants where the kudzu bug is causing the most damage, resulting in significant economic losses for American soybean growers.
The Kudzu Bug
If you saw a kudzu bug, you might think it was a tick or even a dark ladybug. They are pea-sized Asian insects with a hearty appetite for soybeans as well as the weed they’re named after. The bugs range from a green to a dark brown and have square backsides.
Kudzu bugs will produce two generations per year— once in the spring or early summer, and then again in the late summer. They will not bite you, nor will they damage your house in any way but they are one of the largest nuisances because of their habits of overwintering. During the winter, the bugs try to find a warm place to hide from the elements. An out of sight area in your home or garage is among their favorite places, but almost anything indoors will work for them. They are attracted to light colors like your pale clothing, your white car, or your light colored house. Don’t be surprised when you walk around and have kudzu bugs cling to your clothes, and get mixed up in your hair.
Like stinkbugs, to which they’re related, they emit a protective stink. It’s a fruitier smell than stinkbugs’ stench, and has been mistaken at least once, by a woman who called 911, for a gas leak. Others describe their smell as an old can of paint.
Range of Kudzu Bug Quickly Spreading
The kudzu bug is spreading rapidly across the South. First discovered in Georgia in 2009, it has since settled throughout most of Georgia, and the Carolinas. It’s now found in parts of Florida, Alabama, Virginia and Tennessee. Although the kudzu bug is native to Japan, it has adapted well to its Southern environment. They are strong flyers, but also are known to hitchhike on trucks and other vehicles.
Kudzu Bugs Destroy Soybean Crops
While the kudzu bug does feed on kudzu as its name suggests, soybeans have also become a staple in its diet, much to the distain of farmers across the South. Kudzu bugs feed on soybeans by sucking nutrients and moisture from the leaves and stems, causing stress and reducing yields. The bugs attack the stems and leaves, literally draining the life out of the soybeans. It’s reducing the ability of the plant to send the food that it makes from the sun to the fruit and to the seed. This leaves a reduced number of pods per plant, a reduced number of seeds per pod, and a reduced seed size as well.
What Kudzu Bugs Cost U.S. Farmers
A soybean harvest will give farmers about four bushels and acre, with a bushel selling for around $17 each. According to the U.S. Department of Agriculture, growers have observed a 19 percent average yield loss due to kudzu bugs, with a yield high reaching 47 percent. Studies in unprotected plots in Georgia and South Carolina had yield losses averaging 18 percent, with a range of 0-47 percent yield loss in the 19 locations studied. If one acre of soybeans sells for $68, an unprotected soybean crop can expect average loss of $13 an acre due to the kudzu bugs.
Kudzu Bug Control
Thankfully, scientists have come up with insecticides, such as pyrethroids, that kill swarms of kudzu bugs effectively, minimizing the damage the bugs cause to soybean harvests.
The main problem in treating the kudzu bugs is that they reproduce in large numbers, and move about freely; making timing the pesticide sprays a tricky business. It’s starting to become more apparent when treating for kudzu bugs that the problem isn’t killing the bugs, it’s minimizing the amount of money and pesticides needed to do so. Although early attempts to kill them were met by almost immediate re-infestations, more recent tests indicated that it may be possible to avoid losing money to the bugs by spraying when both immature and mature insects are in the field.
There are now have several screening trials in-process or completed for kudzu bug in soybeans. In the meantime, farmers face trying to strike a balance between the cost and timing of insecticides and the damage caused by a new, hungry, invasive pest.