Colorado State Experts Hit on a Safe, Cheap Termite Trap and Zap

Note to Editors: Please also see the January 31 release distributed by Brad Bohlander with the headline COLORADO STATE UNIVERSITY RESEARCH FOUNDATION NAMES RENOWNED ENTOMOLOGIST ‘RESEARCHER OF THE YEAR.’ That release names Bjostad, featured in the information below, as the recipient of the Researcher of the Year award.

Want to hear a horror story? Louis Bjostad, Colorado State University professor of Bioagricultural Sciences and Pest Management, who has spent the last two years studying termite ecology, can recount tales of homeowners discovering thousands of dollars worth of damage that had been going on right under their noses for years. But his recent discovery lends homeowners and exterminators a new, environmentally friendly weapon in fighting termites.

Bjostad and his colleagues have discovered that carbon dioxide attracts termites. CO2 is a small, diffusible molecule that can move through the air or the soil to attract termites from a distance and considerably speed the baiting process used to control and poison termites. This discovery means that carbon dioxide, a compound commonly found in the environment, is an environmentally friendly and inexpensive alternative to chemical baits often used to attract termites to insect traps that contain pesticides.

"Termites find traps more quickly and hit them more actively if the traps are baited with carbon dioxide," said Bjostad. "Our corporate cooperators have found that some termite species weren’t hitting their traps at all, but with the addition of CO2, they are getting hits for the first time ever."

Termites long have been major wood-destroying pests in the South, but the introduction of centrally heated homes decades ago made it possible for termites to become a threat in virtually every region and state in the United States. According to Bjostad, termites cause $4 billion in structural damage annually around the world. That tally includes $1.5 billion in annual damage in the United States, including damage in Colorado, where a myth prevails that termites are rarely a cause for concern.

"Termites excavate wood right up to the surface, and then they stop because they are protected behind that thin layer. It’s your worst nightmare because they eat everything on the inside of your house before you even know that they’re there," he said.

Bjostad and his colleagues, Elisa Bernklau, David James, Matthew Siderhurst and Jason Bishop, are investigating the feeding ecology of termites, an area of research that largely has been ignored but holds promise in controlling the insects. The group of Colorado State researchers also have identified other compounds that attract termites and act as feeding stimulants. These compounds can be used in a simple strategy to bait termites to approach and eat pesticide baits. Until the last few years, termite baiting was not a common control strategy. The chemical of choice to kill the insects, chlordane, became subject to a nationwide Environmental Protection Agency restriction in 1985 after it was determined that the pesticide, which can stay in the environment for hundreds of years, can cause cancer, fertility problems, immune system disruption and damage to the central and peripheral nervous system.

"As long as chlordane was around to control termites, most people just kind of ignored termite ecology. Now that chlordane is illegal, there has been a great surge of interest in understanding termite biology so that we can develop new methods to control them," said Bjostad.

Now when people find that they have a termite infestation, they either must use a different pesticide, a baiting approach or some combination of both. Termite baits are made from paper, cardboard, cellulose or other termite food combined with a slow-acting insecticide that is lethal to termites but benign to other organisms. The bait is contained in a torpedo-shaped monitoring station placed in the ground near the infested home. The strategy is to get the worker termites to feed on the bait, which they then take back and feed to the rest of the colony, poisoning all the termites in the nest. However, one major problem with baiting has been that termites sometimes can take weeks to find the stations buried in the soil.

The team also is working to improve feeding stimulants – chemicals that cause termites to eat more pesticides once baited to a trap – so that traps become more effective. Termites often will eat some pesticide at a trap but abandon it for another food source. The team has been chemically analyzing the types of wood that termites like best and identifying compounds that are unique to those species of trees.

Testing feeding stimulants and baiting techniques has posed a challenge. "The problem you run into almost immediately when you do research with termites is that people who find out that they have termites in their homes understandably have no interest whatsoever in letting us do experiments on the termites," said Bjostad. "That means that if you want to do experiments on termites in the field, you need a source of termites that nobody cares about."

The team solved this dilemma by conducting research on fence posts on ranches in Colorado, where the posts often are infested with termites but are not treated to prevent the infestation.