Fewer than 2% of North America’s bark beetle species attack trees, but those that do have killed billions of conifers across the West over the last 30 years.
In the Insect Ecology and Management Lab at Northern Arizona University, Rich Hofstetter and his team are applying a new approach to detect and deter these tiny but deadly bugs — sound.
Adult bark beetles burrow under tree bark, often targeting stressed trees. Signaling more beetles to join them in a mass attack, they tunnel into living wood, where they lay their eggs.
This environment is full of sap and completely dark, so the beetles can only communicate acoustically. But it’s ideal for their larvae, who eventually kill the tree by eating its inner bark and spreading a damaging fungus.
So Hofstetter and his team have deployed a device called a tactile transducer. It's a bit like a speaker with heavy bass, which transmits acoustic signals as deep vibrations into tree tissue. This disrupts bark beetle communication, reducing the distance the beetles tunnel into trees, as well as their reproduction and survival rates.
The researchers are now experimenting with using sound to deter bark beetles from entering healthy trees in the first place.
With funding from the Arizona Board of Regents, the project’s aim is to make a device to enable foresters and land managers to detect and control bark beetle infestations in trees, without using insecticides.
This Earth Note was written by Diane Hope and produced by KNAU and the Sustainable Communities Program at Northern Arizona University.
