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Posted: January 23, 2013 2:03 p.m.

Scientists trying to thwart kudzu bug

MACON, Ga. (AP) — 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.

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