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Memorial Scholarship

2019 Recipient - Jackson Audley - PhD Candidate, UC Davis

Jackson will present at the 2020 meeting in Alberta, Canada. 

Abstract: Thousand cankers disease is a pervasive, insect-fungal pathogen disease complex, driven by the invasive walnut twig beetle, Pityophthorus juglandis Blackman, that threatens the health of walnut trees across the western U.S., several eastern states, and Italy. The focus of my research has been on understanding the chemical ecology of this invasive bark beetle in order to develop an effective semiochemical repellent tool to protect walnut trees from P. juglandis and thousand cankers disease. I investigated the beetle’s host selection behavior in a riparian forest setting in northern California by examining landing rates on host and non-host branches. The beetles demonstrated host/non-host discrimination prior to landing. Next I tested several compounds individually and in combinations for repellent behavior in flight intercept trials. I found clear evidence of trap catch reduction with both stereo-isomers of limonene, racemic chalcogran, trans-conophthorin, and R-(+)-verbenone (SPLAT) when tested individually. The combination of R-(+)-limonene and trans-conophthorin was selected as the final repellent tool to test in a commercial walnut orchard in northern California based on the previous assays, availability, and cost. The final trials were conducted by assessing P. juglandis landing rates on walnuts treated with the repellent tool. Beetle numbers were significantly reduced on the treated trees. The repellent effect appears to be fairly localized around the release devices and may not confer protection much beyond an individual stem/tree. These results provide strong evidence for developing an effective semiochemical repellent management strategy for protecting walnut trees across the western U.S. and beyond.

Honorees, Donors, and Past Recipients


About the Memorial Scholarship.

In April 1990, Mark Duane McGregor died while conducting forest entomology research in Idaho. He had made many contributions to the field of Forest Entomology particularly in areas of bark beetle management. To memorialize Dr. McGregor, PheroTech Inc (the company for which he worked at the time of his death) and the McGregor family coordinated the establishment of a memorial scholarship fund in Mark McGregor's name.


Acting on that example, colleagues and families of deceased members have donated and raised money in memory of their deceased friends and loved-ones, seeking to memorialize productive lives by contributing to the scholarship of future Forest Entomologists. View the names of honored colleagues and major donors to the Memorial Scholarship Fund. The Western Forest Insect Work Conference has non-profit status and accepts tax-deductible donations for this purpose. Donations may be sent to the WFIWC Treasurer.


In 2000, principal in the scholarship funds had grown to a level that interest generated annually is sufficient to award a scholarship to a worthy student of Forest Entomology. The first award was made in 2001 (view a list of recipients).


View criteria and information necessary for students interested in applying for the next Western Forest Insect Work Conference (WFIWC) scholarship. The application form should be filled out when applying for the scholarship along with all other required information. The deadline for submitting applications for a given year is February 15; for example, the deadline for the 2009 award was February 15, 2009.


Memorial Plaque designed by entomologist John Schmid features the names of deceased honored WFIWC members who have been honored by donations of at least $50, significant donors who have contributed more than $1500 to the fund, and scholarship recipients. The plaque is displayed at annual meetings and resides at the headquarters of PheroTech Inc, Delta, British Columbia, Canada.