June 15, 2012
DAVIS-- UC Davis Department of Entomology graduate student Stacy Hishinuma recently received a grant from the California Garden Clubs, Inc. (CGCI) to further her research on thousand cankers disease, a newly discovered disease that kills black walnut trees.
Hishinuma is researching the walnut twig beetle, Pityopthorus juglandis, which in association with a newly described fungus, Geosmithia morbida, causes thousand cankers disease, (TCD).
Hishinuma, who is seeking her master’s degree in entomology, works with major professor and integrated pest management (IPM) specialist Mary Louise Flint and is co-advised by chemical ecologist and forest entomologist Steve Seybold of the Pacific Southwest Research Station, USDA Forest Service, Davis. Flint, with the statewide UC IPM Program, is the associate director for urban and community IPM, and is an Extension specialist in the UC Davis Department of Entomology. Seybold is an affiliate of the UC Davis Department of Entomology.
At a recent awards ceremony in the Doubletree Inn, Sacramento, Hishinuma delivered a presentation on her research and received the award from CGSI president Julie West.
Hishinuma was one of four scholarship winners honored at the awards ceremony. CGCI bestowed two awards of $2000 each and the National Garden Clubs, Inc., two awards of $3500 each.
CGCI recipients: Stacy Hishinuma (Robert Gordon Scholarship), graduate student in entomology, UC Davis, and Elizabeth Bowman (Maryanne Lucas Scholarship), graduate student in sustainability, Antioch College
NGCI recipients: Paul Steimer (June P. Wood Scholarship), landscape architecture student at Cal Poly, San Luis Obispo; and Lena Butler (Ellame Fehrer Scholarship), environmental studies graduate student at Yale
Thousand cankers disease, first discovered in 2006 in Colorado, is widespread throughout the western states and has now been detected in the eastern states of Tennessee (June 2010), Virginia (May 2011) and Pennsylvania (August 2011). The beetle, believed to be native to Arizona, California, New Mexico and Mexico, was never associated with walnut tree mortality until 2006. The fungus enters the tree when the beetle tunnels into the bark to prepare egg galleries.
Seybold’s research group has led the effort to characterize the disease in California. Scientists believe that TCD occurs only on walnut, predominantly native black walnut, Juglans californica and J. hindsii, although the disease has been recorded on 10 species of walnuts or their hybrids in California. Often the first symptoms of TCD are flagging and yellowing leaves and branch dieback, Seybold said. Affected branches show sap staining and pinhole-sized beetle holes. Beneath the surface are dark stains caused by the fungus.
Related Links:
Stacy Hishinuma Receives McBeth Memorial Scholarship: Entomology website (Dec. 10, 2010)
All About Thousand Cankers Disease: UC IPM website
Discovery of Thousand Cankers Disease: Entomology website (July 2, 2009)
--Kathy Keatley Garvey
Communications specialist
UC Davis Department of Entomology
(530) 754-6894