Soybean Damaging Kudzu Bug Inching Closer to Arkansas

Posted 28 March 2013. Plant Health Progress.

Source: University of Arkansas Press Release. www.uaex.edu

Lonoke, Arkansas (March 18, 2013)--The kudzu bug, an insect that has caused up to 20 percent yield losses in some untreated soybean fields in North Carolina, is inching its way nearer to Arkansas, said Gus Lorenz, extension entomologist for the University of Arkansas System Division of Agriculture. 

The kudzu bug is native to India and China and was first found in the United States in 2009. It’s a tiny insect – just one-sixth to one-quarter of an inch long and is olive green with brown speckles. They waddle when they walk, but are excellent fliers. 

“The kudzu bug has been a serious pest of soybeans in Georgia, the Carolinas, Virginia, Florida, Alabama and Tennessee has now been found in Vicksburg, Miss.,” he said. “That’s too close for comfort for us in Arkansas and the rest of the Mississippi Delta.

“It’s only a matter of time before the bug finds its way to Arkansas,” Lorenz said. A map of its current distribution can be found here: www.kudzubug.org/distribution_map.cfm.

Surveys done in 2012 along I-40 in Crittenden County; U.S. 49 in Phillips County and Arkansas 159, U.S. 65 and U.S. 82 in Ashley and Chicot counties indicated no bugs. 

The bugs can overwinter in houses and other structures and in early spring become active, seeking places to lay eggs in emerging kudzu or soybean plants. 

The bugs, both in the adult and nymph form, “gather in large groups and suck sap from a host plant, weakening and stunting the plant’s growth,” he said. “Severe infestations can cause the plant to lose its leaves.” The insects can also reduce the number of soybean pods per plant, reduce the number of beans per pod or reduce the size of the beans in the pods. 

The bugs are tricky to control. Lorenz said that any treatment must be done carefully since treating for kudzu bugs can interfere with beneficial insects and provide an opening for other pests such as corn earworms, soybean loopers and armyworms. 

Timing control methods is very important, he said. When scouting for this pest, “we are suggesting a threshold of one immature kudzu bug per sweep.”

Kudzu bugs are also a pest to homeowners, and can congregate in large numbers in homes. Entomologists recommend vacuuming the insects up and preventing them from releasing a noxious chemical that can also stain home interiors. (www.kudzubug.org/docs/GAkudzubugalert2012.pdf).

For more information about controlling pests, contact your county extension agent, visit www.uaex.edu or visit Arkansascrops.com.

Contact:
Mary Hightower
501-671-2126
mhightower@uaex.edu

Scientists trying to thwart kudzu bug's destructive march

From The Telegraph - Middle Georgia's News Source 

By S. HEATHER DUNCAN — hduncan@macon.com

 

At last, the “Vine that Ate the South” may have met its match.

To most longtime Southerners, it sounds great: a bug that loves to eat kudzu and can kill off half an infestation of the tangled vine in a couple of years.

What’s not to like?

A lot, it turns out.

The bean plastapid, commonly called the kudzu bug, also likes to eat soybeans as well as wisteria and some ornamental plants. (Kudzu, wisteria and kudzu bugs all come from Asia, especially Japan.) Like stink bugs, kudzu bugs smell bad, and like ladybugs, they try to come inside people’s houses. They fly in clouds and form clumps of thousands on white homes. The insect leaves behind orange stains when smashed and gives some people a skin rash.

In a debate about which is the bigger pest, kudzu might actually lose. Georgia is the first state the bugs invaded from Japan, and since 2009 they have spread with breathtaking speed.

Tracie Jenkins, an assistant University of Georgia professor of applied insect genetics who lives in Macon, said the earliest ones were found in 2008. In 2009, they had become a pest to home­owners in eight or nine suburban counties around Atlanta, where they apparently spread from Hartsfield-Jackson Atlanta International Airport.

“Homeowners were going nuts around Atlanta,” Jenkins said. “Tens of thousands of these stinky little bugs were attaching themselves to the sides of people’s houses.” The bugs are attracted to light-colored paint on cars and houses and to tall things and people as they mate and seek crannies in which to overwinter.
Every female kudzu bug can lay 250 eggs a season, and there can be so many bugs in one infestation that a single sweep of a 15-inch-wide butterfly net gathers hundreds, Jenkins said.

Now they are found throughout Georgia and South Carolina and in six other states, as well as Central America.

The question is how to slow the spread or reduce their destructive power. First, UGA scientists pooled their knowledge and requested help from Asian colleagues to identify the bug. Then they continued their detective work.

Jenkins examined the bugs’ DNA and found that they all descended from a single female line. Then she sequenced the bug’s entire genome. The detective work can be more fun than the field work in this case. Jenkins gathered hundreds of kudzu bugs from a foreclosed house overrun with kudzu in an upscale north Bibb County neighborhood. Driving them home, bagged in freezer bags, left her car reeking. She stored them on ice in a cooler that she subsequently had to throw out.

Now she’s using DNA from more than 300 bugs collected in eight states, looking for genes that offer the bug resistance to insecticides, which could be targeted for changes that would weaken the insect. Jenkins wants to examine the genetic diversity of the bugs -- variations in their genetic building blocks -- using DNA from not only the Southeast but also from kudzu bugs from China, India, South Korea and even Honduras. Bugs apparently came from those countries to Atlanta by plane.

Aside from changing the genetic code of the bug itself, Jenkins has identified another option. She and colleagues at other universities are working on three different kinds of bacteria that live within the bug, apparently helping it digest its food and perhaps perform other functions.

“So you have this machine with six legs and an exoskeleton, and inside you have gears made up of three bacteria,” Jenkins said. Without at least some of these bacteria, the bugs would probably die, so tinkering with the gears might make the machine break down, Jenkins said.

While she pursues genetic solutions to the kudzu bug invasion, other entomologists investigate the possibility of importing another insect to prey on the kudzu bug. On its home turf, the insect is kept in check with the help of a wasp that lays its eggs in the eggs of the kudzu bug. These wasps are being tested to see if releasing them here would harm only the kudzu bug -- or some native insects as well. Jenkins said some native wasps also have laid their eggs inside kudzu bug eggs.

“Nature has a way of righting itself,” she said.

Dining on soybeans
At first, it might seem that the kudzu bug itself is an example of nature correcting the kudzu problem. The insect has sucking mouth parts that it inserts into the stem.

Jim Hanula, an entomologist with the U.S. Forest Service in Athens, has found the bugs are able to reduce the size of a kudzu patch by half within two years.

“They are not going to completely eliminate kudzu,” he said, but scientists want to study the long-term effect of the bugs on the vine’s resilience. Kudzu relies on its root system when its leaves die back each winter. If bugs aggressively feed on it year after year, that could reduce the energy reserves in the plant’s roots, allowing trees to grow through the vines, Hanula said.

Unfortunately, kudzu bugs cause the same kind of stress to soybeans, diverting the plant’s energy from bean production and reducing yield. According to the state Cooperative Extension Service, about 180,000 acres of soybeans, with a value of more than $168 million, are planted in Georgia a year. And soybean prices have been higher than usual lately.

UGA entomology professor Phillip Roberts said scientists in Tifton have conducted 24 field trials over the past three years, concluding that the kudzu bug causes a 20 percent loss in soybean yield if farmers don’t spray infested areas. He said research from the most recent growing season suggests that soybeans planted earlier will be less susceptible to kudzu bugs.

He said he hopes next year to figure out more about the “sweet spot,” when the bugs are done moving and a single spray could eliminate them from a field for the year. Roberts said a $10-per-acre insecticide treatment at the right moment in a few fields around Tifton saved 20 bushels an acre -- about $300 worth of yield.
What Roberts learns could be important not only for Georgia farmers but also for Midwestern farmers, whose soybean crops are much larger.

The kudzu bug is expanding its range rapidly and likely will move anywhere kudzu lives, Jenkins said. The ease of international travel, combined with global warming, probably will expand the range of invasive species like the kudzu bug that rely on a temperate climate. Georgia’s own springs are coming a month sooner, and summers are ending a month later than in the past, she noted.

In Dodge County, where about 3,500 acres were planted in soybean, growers were fortunate that the bugs became most active after beans had already set, county extension agent Greg Slaughter said.
In Taylor and Peach counties, farmers were not so lucky.

“It’s amazing how quickly they have adapted and overrun us,” said Jeff Cook, the county agent for both. He said almost all his farmers sprayed for kudzu bugs, which became prevalent when the plants were still seedlings.

In fields near kudzu, he said, “you could drive by the field and smell them. You could easily find 10 to 20 on a plant.” The kudzu patches themselves looked as if they’d been hit by frost in the summer.

Cook said the bugs probably did reduce crop yields. He said the soybeans probably should have been sprayed sooner, but farmers were trying to reduce their costs by conducting all their fungicide and insecticide treatment at once.

“Soybeans used to be something we planted and went and tended our cotton and corn,” Cook said. “Now, all the time it’s a few more dollars we’ve got to throw out in the field.”
 
But Cook doesn’t have to drive to a soybean field to find kudzu bugs.

“I have a white house, and when the day warms up they’ll be like gnats,” he said. They killed his chrysanthemums and ate his peppers and wisteria. He has to spray his window screens, soffits and window edges with pesticide.

“I have a kudzu bug graveyard around my house,” he quipped. They even get under the straps on deer stands.

“It would be great if we could get rid of them,” Cook said. “But they’re here to stay.”

To contact writer S. Heather Duncan, call 744-4225.

Read more here: http://www.macon.com/2013/01/02/2303333/scientists-trying-to-thwart-kudzu.html#storylink=cpy

Kudzu Bug Found In Western Mississippi

Up until now, the farthest west the invasive pest had been documented was Escambia County, Alabama, which put it two counties east of the Alabama-Mississippi line. Here’s a map of the insect’s current range in the South, which now shows the Mississippi sighting.

The fact that the pest has literally jumped across the state probably has to do with its ability to hitch rides on vehicles....

Please visit Agfax for the complete news article.

Kudzu vine key to kudzu bug’s survival

University of Georgia  |   July 3, 2012 

U.S. Forest Service entomologist Jim Hanula may be the only person in the South who actually wants to keep kudzu alive.

He needs healthy plots of the famous weed to monitor the effect the bean plataspid—a pest that entered Georgia some two years ago and has become known as the kudzu bug—is having on kudzu.

“Kudzu is known as the vine that ate the South. The roots can grow 12 feet deep and weigh 300 pounds,” said Hanula, who has an adjunct appointment with the University of Georgia College of Agricultural and Environmental Sciences.

Kudzu, and the new pest that feeds on it, came to the U.S. from Asia. The U.S. government promoted kudzu for erosion control in the early 1900s, and by 1946 the vine had spread or was planted on 3 million acres of land, he said. It now occupies 7 million acres and covers 50,000 new acres each year.

Since the bean plataspid arrived in Georgia, Hanula has been knee-deep in kudzu patches trying to learn about the bug’s life cycle and behavior—and how it affects kudzu health.

The pest eats the vine, but it overwinters on the bark of nearby trees. Those that survive winter lay eggs on kudzu in the spring. Their young, called nymphs, feed on kudzu and emerge as adults in late June and July. The insects then go through the same process again, with the next generation of adults emerging in September and October.

“It is these adults that will overwinter and start the whole process next year,” Hanula said.

Hanula has been taking weekly samples of the pest from research kudzu patches to study its biology.

He and Forest Service entomologist Scott Horn tested a variety of colored traps to attract the bug and found it is not attracted to red, purple or black; it favors white most and yellow to some degree. This explains the hundreds of calls UGA Cooperative Extension agents receive from owners of white homes or cars.

To determine how the pest damages kudzu, Hanula harvests the stems and leaves of infested kudzu patches and compares them to the patches he sprayed to protect them from the kudzu bug.

“The pest caused a 33 percent reduction in kudzu growth after one year,” he said. “…we will monitor for several more years to see if the trend continues.”

The Forest Service and UGA scientists hope continual feeding by the pest will deplete kudzu roots and weaken the plants.

“If the bug’s effect is cumulative, kudzu plants will likely weaken, and patches won’t be as thick,” Hanula said. “Hopefully, the bug will reduce kudzu’s ability to climb, which would be good for forestry.”

Much of the land now covered by kudzu is ideal for growing trees, so anything that slows kudzu growth is good for forestry, he said.

Kudzu bugs dining on kudzu may sound like a reason to celebrate; the flipside is that the kudzu bug also loves to feed on soybean plants and other legumes. Georgia farmers grow soybeans for the oilseed and animal feed markets.

UGA entomologist Phillip Roberts has seen the pest reduce soybean crop yield by 19 percent in untreated fields. On a positive note, the bug does not feed on soybean pods.

The kudzu bug was first spotted in Georgia in the fall of 2009 when insect samples were sent to the UGA Homeowner Insect and Weed Diagnostic Laboratory in Griffin. The first samples came from UGA Cooperative Extension agents in Barrow, Gwinnett and Jackson counties.

“As of now, the bug has been reported in 154 of Georgia’s 159 counties—only five along the coast remain unconfirmed,” said Wayne Gardner, a Griffin-based UGA entomologist who has been studying the pest since it was found in Georgia.

The kudzu bug also has been found in all 47 South Carolina counties, 73 North Carolina counties, 25 Alabama counties, two Virginia counties, four Tennessee counties and six Florida counties, he said.

“I think that’s 312 counties in seven states, which is a total land area of 147,342 square miles,” Gardner said.

For tips on controlling kudzu or the kudzu bug, see www.caes.uga.edu/publications/ and search for kudzu or kudzu bug.