- Author: Kathy Keatley Garvey
- "A Study of Landing Behaviour by the Walnut Twig Beetle, Pityophthorus juglandis, Among Host and Nonhost Hardwood Trees in a Northern California Riparian Forest" (https://doi.org/10.1111/afe.12385).
- "Walnut Twig Beetle Landing Rates Differ Between Host and Nonhost Hardwood Trees under the Influence of Aggregation Pheromone in a Northern California Riparian Forest" (https://doi.org/10.1111/afe.12410)
The walnut twig beetle, in association with the fungus, Geosmithia morbida, causes the insect-pathogen complex known as "thousand cankers disease," which wreaks havoc on walnut trees. The insect, measuring about 1.5 millimeters long, is smaller than a grain of rice.
"The first study is one of few bark beetle host selection studies conducted without the use of semiochemical lures," Audley said. "Together, both studies provide strong evidence for directed flight host searching and in-flight, host discrimination behaviors by Pityophthorus juglandis. These papers highlight sources of and provide an ecological context for potential non-host, volatile compounds that may be of use in semiochemical repellents to protect walnut trees from attack by P. juglandis."