In a new paper published in the Journal of Economic Entomology, two researchers from Northern Arizona University pitted lab-raised bedbugs against four commercially available sound-based devices: the Transonic Pro, made by Chicago-based BIRD-X; the SonicIQ Ultrasonic pest repeller from SmartWorks; Pest Free, made by Orlando, Fla.-based ViaTEK; and the Riddex bed bug killer, from Global TV Concepts in Deerfield Beach, Fla.
The researchers created testing arenas for each device, consisting of two buckets connected by a middle chamber. One bucket contained the sonic device, while the other was left empty. There was also one control arena where neither bucket contained a sonic device. At the start of each experiment, the bedbugs were placed in the middle chamber between the arenas, and the ultrasonic device was turned on for half an hour.
Then, the scientists looked to see if the bedbugs responded to the devices. But they found that the bugs were neither repelled by nor attracted to the sounds of the repellers.
“Our results confirm that commercial devices producing ultrasound are not a promising tool for repelling bedbugs,” the authors wrote.
The researchers admitted there may be some limitations to their study -- there were no chemical cues in the experimental arenas, so there was no way to see if the sound devices would have repelled bedbugs from the scent of a meal.
But the work does jive with previous studies showing that ultrasonic devices have little effect on other kinds of annoying insects. Some studies have even shown that sound-based devices can increase the number of cockroaches in rooms or aggravate mosquitoes and increase their biting, according to the paper.
One of the problems with making sonic devices aimed at bedbugs is that there is little known about their sensitivity to sound. Much work has been done on bedbug communication through pheromones, which can be used to attract mates, sound an alarm or start fights. Bedbugs are also known to use vision and touch to orient themselves.
Plus, it's unclear what sorts of sounds would attract or repel bedbugs. Since they tend to live among humans, they are constantly exposed to our attendant sounds -- breathing, snoring, even the hums and whirs of machinery like air conditioners, kitchen appliances and home electronics.
So while current sonic products seem to have no effect on bedbugs, it is possible that future devices could exploit low-frequency sounds like snoring to lure the critters toward some death trap.
“Future studies of bedbug bioacoustics may be served well by using low-frequency sounds produced by host species,” the authors wrote.
SOURCE: Yturralde et al. “Efficacy of Commercially Available Ultrasonic Pest Repellent Devices to Affect Behavior of Bed Bugs (Hemiptera: Cimicidae).” Journal of Economic Entomology published online ahead of print.