Researchers have enlisted a new weapon against bed bugs: their own chemical signals. It's first time scientists have used any insect's alarm pheromones as a method of control.
While the new technique probably won't single-handedly solve anyone's bed bug woes, experts say, the research may add to our arsenal of tools for fighting what has become a disturbing nuisance for a growing number of people.
"To control bed bugs, there's not going to be one easy solution," said Joshua Benoit, an entomologist at Ohio State University in Columbus. "We are trying to encourage people to find new and creative ways to kill bed bugs."
Bed-bug infestations have been on the rise in recent years, Benoit said, probably because people travel so much. All it takes is one pregnant female hopping a ride in a suitcase for a new crop of insects to invade homes and apartment buildings.
The tiny critters don't spread diseases, but a single person can easily get a few hundred bites in one night. Those chomps cause intense itching and even scarring in some people.
So far, there is no ideal way to get rid of bed bugs. Pesticide treatments can be expensive, invasive, toxic, and often ineffective. Already, the insects have developed resistance to some of the most common chemicals used to fight them.
In an effort to get the upper hand, Benoit experimented with alarm pheromones — the chemicals that bed bugs release when they're disturbed or in danger. In turn, their comrades get excited and start scurrying around.
Benoit and colleagues mixed synthetic versions of bed-bug alarm pheromones with desiccant dust, a pesticide that works by drying insects out. In order to work, the bugs need to run directly through the dust.
The researchers placed varying concentrations of these mixtures in Petri dishes and in small enclosures that contained hiding places for the insects. Then they added bed bugs.
Their results, published in the Journal of Medical Entomology, showed that mixtures of alarm pheromones and desiccant dust killed up to 50 percent more bed bugs than did desiccant dust alone. The idea is that the pheromones get the bugs to move around more, making them more likely to run through the dust, which is relatively non-toxic and inexpensive.
"This is the first study of its kind to use alarm pheromones in this manner," Benoit said, "for any insect."
It's still way too soon to recommend that people run out and buy alarm pheromones (which are synthesized for other purposes, including as food preservatives). Outside the confines of a plastic dish, getting bed bugs to run around like crazy is not necessarily a good thing, said Michael Potter, an urban entomologist at the University of Kentucky, Lexington. Bed bugs are notoriously good at getting behind baseboards, inside walls, and into other cracks and crevices.
"Some might run into the apartment next door," Potter said. "Some might run into inaccessible areas."
In one recent incident in Columbus, Ohio, Benoit said, bed bugs had infested 23 out of 24 units in an apartment building. Residents had to leave their homes for a week while the building was fumigated. Even then, there was no guarantee that the treatment killed all the bugs.
The incident illustrates how important it is to continue learning more about the inner workings of these pests.
"Any new work on bed bugs," Potter said, "is interesting work."
More on bed bugs