[Termite Control] Starving Termites

Researchers at the University of Florida have discovered tiny organisms that they say could give PCOs another tool in their arsenal to fight one of the most common pests in the industry.

Earlier this year, researchers  announced the discovery of four enzymes in termites that do the legwork of cellulose digestion. The enzymes, called cellulases, come both from the termites and the protozoa that live in the insects’ gut — the only place on earth the specific single-celled organisms are found.

“We think we can find brand new targets for insecticides that can disrupt termite digestion,” said Michael Scharf, professor of entomology and insect toxicology at the University of Florida. “By designing specific inhibitors of those enzymes, we can starve those termites and cause those colonies to collapse.”

MORE BAIT OPTIONS. University of Florida Entomology Professor Dr. Phil Koehler said the research could give pest management professionls a new tool to tackle termites, one that is an alternative to traditional treatments.

“The idea is, in the end, that we end up with a bait that would affect termites and really not affect anything else,” Koehler said. “It would be good to target (only) things that digest cellulose.”

Humans can’t digest cellulose (think of all the roughage you were forced to eat as a kid), and thus don’t have any of the enzymes that would be targeted by a new bait. Older chemicals used to treat wood in structures contained heavy metals or attacked an insect’s nervous system, which could make some customers a little wary.

EFFICIENT EATING MACHINES. Termites love wood — specifically cellulose, the sugar it’s made of — so much so that they digest nearly 100 percent of it. “What goes in, almost none of that comes out the other side,” said Scharf.

But most of the legwork for digesting such a dense plant material is actually done by protozoa in the termites’ gut. These single-celled organisms produce three of the four enzymes researchers have discovered; termites themselves can claim the fourth.

“By looking for the genes, we can ultimately learn about the biology,” Scharf said.

BIOLOGY AND BEHAVIOR. And that biology is the next hurdle in scientists’ research. University of Georgia Researcher Dr. Brian Forschler has spent the last 15 years studying termite behavior, most recently with an experiment involving 36 termites and 300 hours of video tape.

“It’s about time we started looking at this in a little bit more detail,” Forschler said. “What they’re doing is good, and there’s something good that can come out of it. It’s just awesome.”

The challenge that comes with applying the new findings to pest control, he said, is formulating an insecticide that has a strong residual. Two-thirds of the food termites eat already has been either partially or entirely digested by another termite, and any chemical that shuts down the insects’ digestion of cellulose would have to be palatable the second or third time around.

“It has to pass through their gut and stay with them, rather than (only) pass through their gut,” Forschler said. “Their (eating) behavior is unpredictable and rather erratic.”

And, said Scharf, no one yet knows what termites would do if their cellulose enzymes were turned off.

“There are certain operational barriers to achieving the death of a colony, so we have some question marks still,” he said, such as what, exactly would happen if a pest management professional applies a new type of bait. “How do you get termites to take it back to the colony and share? Do they (then) get more hungry? Do they eat more of your house?”

The author is assistant editor of PCT magazine.

Could Termites Save Us Money at the Gas Pump?

Another potential boon to the new research on termite enzymes is its application to the production of biofuels. After termites digest the complex sugar cellulose, it becomes a simple sugar called glucose, which is used in the production of ethanol.

“When they’re broken apart, they’re very useful in ethanol production,” said entomologist and University of Florida researcher Phil Koehler.

Scientists say that the enzymes of termites and the single-celled organisms that live in their guts be added to algae that, when grown, could be used to digest cellulose — think scrap wood and waste paper — on a massive scale.
Koehler said such a set up could be established next to a landfill, and wouldn’t put any additional strain on corn supplies.