They are applying the results of nearly a decade of acoustic research in an unconventional collaborative effort to stop bark beetles from tunneling through the living tissue of weakened, drought-stressed pine trees.
The trio has now received a patent for a device that uses sound as a targeted sonic weapon to disrupt the feeding, communication, reproduction, and various other essential behaviors of the insects.
Dunn said: "When massive tree death started occurring in Northern New Mexico where I was living, I became curious if there were sounds associated with such a large amount of biological activity.
"At that time there was still the assumption that this was the result of a local bark beetle infestation due to drought conditions. Since then, we have come to realize that this was not just a local outbreak but one of many outbreaks across all of the western states and Canadian provinces that has been driven by climate change conditions. Many scientists think that we are experiencing the largest insect infestation of North America in the fossil record of the Earth," he added.
Dunn spent a few weeks thinking about how to listen to the interior of trees and soon came up with a simple listening device that cost less than $10 to build.
"After making hundreds of hours of recordings inside hundreds of trees, I made a large sound composition that represented the incredible diversity of sounds made by a couple of species of bark beetles and their changing responses to the life cycle of tree hosts that they invade. This was released as a CD (The Sound of Light in Trees) that garnered a lot of attention from both the sound, art, and music community, as well as various scientists involved in bio-acoustic research.
"After that interest emerged, I was approached by my future colleagues at Northern Arizona University who not only wanted to replicate what I had done, but to collaborate on how to push this research further. These further results led to the device and protocol that we have just patented."
Dunn said that he and his colleagues at Northern Arizona University - Richard Hofstetter and Reagan McGuire - hope to produce a range of products as a result of their patent to combat bark beetles, as well as other insects related to them.
He added that scaling up the device to be effective in saving large forests might be possible through the use of local wireless or FM broadcast to protect select areas of forest, depending on how cheaply they can produce an effective system that can be applied to individual trees.
"One major obstacle is the issue of how to miniaturize the analog circuits and sample playback," said Dunn. "One of my brilliant graduate students, David Kant in music, has been working on putting all of this into digital form and has largely succeeded. If we can solve that problem and come up with viable output transducers, amplification, and solar power solutions, it's very doable."