Knowing which termites are kin and where they've been may be the key to more effectively controlling the pests. And scientists are closing in. They're using DNA technology to track their travels and find their family trees.
"I'm looking at what we call gene flow, which is the genetic relationship of one termite to another," said Tracie Jenkins, a geneticist working in the University of Georgia's entomology department.
"DNA can be used to determine termite relationships just as it is used to determine human relationships," Jenkins said. "It can also be used to track termite movement over time."
Atlanta and Louisiana Termites From Same Family
Jenkins tested the DNA of termites found at four sites in metro Atlanta. She found that they came from Louisiana and traveled to Georgia inside railroad ties.
In her lab at the Georgia Experiment Station in Griffin, Ga., Jenkins examined a mitochondrial DNA gene from the Formosan subterranean termites, an imported species.
"The mitochondrial DNA gene is inherited from the female line and therefore can be used to trace maternal movement," Jenkins said. "By comparing the Atlanta collections with collections from many other sites in the Southeast and elsewhere, I discovered a match with sites in Louisiana."
Surveying the four Atlanta homeowners, Jenkins found they all bought infested railroad ties for landscaping. "This study demonstrates how interstate commerce can help spread termites," she said.
As a result of the research, she said, the Railway Tie Association is alerting the railroad community to the possible problems of spreading Formosan termites in crossties. And they're taking steps to prevent it.
Jenkins' genetic research is part of the UGA College of Agricultural and Environmental Sciences' urban agriculture effort. By understanding termites' family relationships and movements, she said, the $2-billion-a-year pest may be better controlled.
"You have to know your enemy before you can fight him," she said. "You can't treat for a creature if you don't know how it operates."
Do Colonies Really Have Just One Queen?
Jenkins said subterranean termite colonies are traditionally described as having one king and one queen. The mated pair's mature offspring fly away and start new colonies.
After studying termite sites across Georgia and the world for the past five years with UGA urban entomologist Brian Forschler, Jenkins isn't sure she agrees with the one-king, one-queen scenario.
At one termite site on Georgia's Sapelo Island, Jenkins and Forschler found termites of one species one month and another species the next.
Jenkins' research also provided DNA evidence that different species traveled through the same site. Her DNA work uncovered evidence, too, of four termite species at the site. Entomologists knew three of those were in Georgia. But one is new to the state.
"In this one study we determined they move rapidly when they want to, different species can come in and occupy the same site and there are most likely more than three species in Georgia," she said. "This opened up a whole new research project for me. I'm obsessed by what I'm learning."
High Cost of DNA Sequencing Slows Research
The only problems standing in Jenkins' way are the numbers of hours in a day and the high cost of DNA testing.
"I'd like to be able to run more DNA fingerprinting and DNA sequences," she said. "But DNA work, although extremely informative, is very, very expensive. So I have to design my experiments with cost in mind."
Jenkins' next steps are to find whether more than one queen is in each colony and if different species coexist and feed in the same site.
"Every day I'm ferreting out their biology and how they work," she said. "Termites are interesting creatures. But because they're a homeowner's nightmare, I hope my work will help in the fight to control them."
(Sharon Omahen is a news editor with the University of Georgia College of Agricultural and Environmental Sciences.)