It's about the size of a grain of rice but it's a killer.
That's the walnut twig beetle, Pityophthorus juglandis, which in association with a newly described fungus, Geosmithia morbida, causes thousand cankers disease, wreaking havoc on native black walnut trees.
Enter doctoral student Jackson Audley of the Steve Seybold lab, UC Department of Entomology and Nematology. He will present a seminar on "Protecting Trees from Bark Beetle Attacks Utilizing Semiochemical Repellents: A Case Study with the Walnut Twig Beetle” at a seminar from 4 to 5 p.m., today (Wednesday, Oct. 25) in Room 3001 of the Plant and Environmental Science Building.
The seminar is part of the UC Davis Forest Biology Research Center Seminar Series and his presentation is a preview of his thesis project.
"In this talk I will discuss the theoretical construct of semiochemical repellents for protecting trees from attack by bark beetles and demonstrate the process of developing a repellent tool with my work on the walnut twig beetle, Pityophthorus juglandis, the vector of thousand cankers disease in walnuts," Audley says in his abstract. "Bark beetles can constitute a significant threat to tree health and are a significant disturbance agent in forest ecosystems. Semiochemicals have been successfully utilized to protect individual to stands of susceptible trees from various bark beetle pests. Most of this work has been conducted in coniferophagous bark beetle systems. My work here at UC Davis has been focused on bringing those same techniques into studying an invasive, hardwood-attacking bark beetle system."
Audley received his bachelor's degree in wildlife biology and natural resource recreation and tourism in 2009 from the University of Georgia, and his master's degree in forestry in 2015 from the University of Tennessee. As a master's student, he did research on the walnut twig beetle, including treatment tests.
The walnut twig beetle is believed to be native to Arizona, California, New Mexico and Mexico. In 2006, plant pathologist Ned Tisserat and entomologist Whitney Cranshaw of Colorado State University identified the pathogen in declining black walnut trees in central Colorado. The disease has now spread throughout much of the United States.
"Often the first symptoms of thousand cankers disease (TCD) are flagging and yellowing leaves and branch dieback," says Seybold, one of the pioneering TCD researchers. He is a chemical ecologist with the USDA Forest Service, Pacific Southwest Research Station, Davis, and a lecturer/researcher with the UC Davis Department of Entomology and Nematology. "Affected branches show sap staining and pinhole-sized beetle holes. Beneath the surface are dark stains caused by the fungus."
"The fungus enters the tree through the feeding or reproductive activities of the beetle, and colonizes and kills the phloem and cambium of the branches and main stem," according to the UC Integrated Statewide Integrated Pest Management Program website, content that's the work of Steve Seybold and entomologist Mary Lou Flint, then associate director of of Urban and Community IPM, and now UC Extension entomologist emerita. The disease gets its name from the large number of dark cankers that rapidly develop on affected branches.
The UC Davis Forest Biology Research Seminars, which began Oct. 11, are held Wednesdays at 4 p.m. in Room 3001 of the Plant and Environmental Science Building.
The remaining schedule includes:
Nov. 1 – Alison Scott, postdoctoral student, UC Davis Department of Plant Sciences, “The Polyploid Origin and Evolutionary History of California Redwoods”
Nov. 15 – Brian Smithers, Ph.D student, Ecology Graduate Group, "Mechanisms of Range Shifts in Great Basin Sub‐Alpine Bristlecone Pine Forests."
Nov. 29 – Sarah Bisbing, assistant professor, Forest Ecosystem Science, Department of Natural Resources and Environmental Science, University of Nevada, Reno, "Looking Backward to See Forward: Causes and Consequences of Altered Disturbance and Climate on Western Conifer Forests.”
Dec. 6 ‐ Ryan Tompkins, Forest Silviculturist, U.S. Forest Service/Plumas National Forest, “Sierra Nevada Silviculture in the New World Order: Challenges, Uncertainties, and Opportunities”
For more information, contact David Neale at firstname.lastname@example.org.
All is still not right in the bee world. And all is not right with science. Its future is troubling.
That's why it's so important to "March for Science" on Saturday, April 22. All eyes are focused on the national March for Science in Washington, D.C., and the satellite marches in solidarity.
We're glad to see that the 7000-member Entomological Society of America (ESA), a non-partisan scientific society founded in 1889, is taking an active role by naming its members "point persons" for the various marches.
At the Sacramento March for Science, UC Extension entomologist emerita Mary Lou Flint of the UC Davis Department of Entomology and Nematology, is ESA's point person. “It is a really important time to be supporting science and scientists in the United States," she said. "This march is nonpartisan and fully sponsored by the ESA.”
In Sacramento, participants will gather at 10 a.m. at Southside Park, 2115 6th St. for a pre-march program. At noon they will begin marching to the Capitol Mall, 1315 10th St. The post-march program will take place there from 1 to 4 p.m.
Flint, a UC Davis graduate who holds a doctorate in entomology from UC Berkeley, retired in June 2014 as an Extension entomologist and as a leader in the UC Statewide Integrated Pest Management (UC IPM) Program: she served as the associate director for Urban and Community IPM.
On April 22, she will be there with other scientists, out of their labs, and into the streets. And joining thousands of others, all marching for science.
The guiding principles of ESA "recognize that the discipline of entomology is global, that all of its members must be able to participate fully in the organization, and that entomologists must collaborate with government and the public to maximize the positive benefits insect science offers to the world," said ESA in a press release. "The stated goals and principles of the March for Science align closely with these strategic principles of ESA.”
ESA is the largest organization in the world serving the professional and scientific needs of entomologists and people in related disciplines. Its members are affiliated with educational institutions, health agencies, private industry, and government. Members are researchers, teachers, extension service personnel, administrators, marketing representatives, research technicians, consultants, students, and hobbyists.
ESA has created a web page to share information on how members can participate in the March for Science in Washington, D.C., or at satellite events around the nation and the world. ESA is also planning a pre-March for Science webinar on April 19 at 2 p.m. (EDT). Speakers from ESA, Lewis-Burke Associates, and the American Association for the Advancement of Science (AAAS) will discuss the logistics of the March for Science, best practices for non-partisan advocacy on behalf of science, and advice for productively engaging with the media during and after the March.
In addition, ESA members and others can use an ESA template to print their own "Why I March for Science" sign. They are encouraged to take a selfie with it, and send it to email@example.com. "Why I March" pictures will be shared on social media in the days leading up to the event.
The March for Science is not only intended to raise awareness, but to celebrate science and to support and safeguard the scientific community. The goals include advocating for open, inclusive, and accessible science, affirming scientific research as an essential part of a working democracy and, in general, supporting scientists.
As the Sacramento March for Science web page points out: "Recent policy changes have called science-based information into question. Science is not a partisan issue. Science is fact-based and provides objective results. It is time for people who support scientific research and evidence-based policies to take a public stand and be counted!"
"We come from all walks of life. We are of different races, religions, gender identities, sexual orientations, abilities, socioeconomic backgrounds, political perspectives, and nationalities - and we are united through our respect for science and our belief that it is crucial to the health and success of our society and our planet. Our diverse opinions, perspectives, and ideas are critical to the scientific process and are our greatest strength."
If you live in the Sacramento area, check out these related links, and then join the march to the state capitol:
UC Davis entomology doctoral student Stacy Hishinuma has received and accepted a position in the USDA Pathways Internship Program with the Region 5 field office of the USDA Forest Service, San Bernardino.
Hishinuma studies the walnut twig beetle, Pityophthorus juglandis, which in association with a newly described fungus, Geosmithia morbida, causes thousand cankers disease (TCD) of walnut and butternut trees.
The walnut twig beetle is believed to be native to Arizona, California, New Mexico and Mexico. In 2006, plant pathologist Ned Tisserat and entomologist Whitney Cranshaw of Colorado State University identified the pathogen in declining black walnut trees in central Colorado. The disease has now spread east of the Mississippi to states in the heart of the valuable black walnut timberlands. Most recently it was reported from Indiana. Latest collection records show that the beetle and pathogen are now known from nine states in the western United States and seven states in the eastern USA. In 2013 the disease was also reported in Italy marking the first time that it occurred in Europe.
Hishinuma works with major professor 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, an affiliate of the department. Flint is an Extension specialist emeritus with the UC Davis Department of Entomology and Nematology and a former associate director with the UC Integrated Pest Management Program.
“USDA will provide some financial support during the end stages of her Ph.D. thesis, in exchange for 320-640 hours of work and training over the next 14 months,” said Seybold. Then, in June 2016 her position will be converted to that of a permanent entomologist with the USDA Forest Service office in San Bernardino after she has completed her thesis. She will be responsible for forest insect survey, detection, and management on four national forests in southern California ranging from San Diego to Monterey counties.
“The highly competitive internship and guaranteed position are a credit to her and her achievements,” Seybold said.
Seybold and Flint assisted her in developing the internship, as did Richard “Rick” Bostock, UC Davis professor of plant pathology.
Hishinuma won the 2013 Western Forest Insect Work Conference Memorial Scholarship for her research on TCD and presented her work at group's 65th annual conference, held March 31-April 3, 2014 in Sacramento. She also received two scholarships from the California Garden Clubs, Inc. (CGCI) and a McBeth Memorial Scholarship to support her research on TCD.
Seybold's research group has led the effort to characterize the disease in California and to develop a nationwide detection program for the beetle. They recently published two papers in the journal PLOS ONE that characterize the genetic diversity and invasion patterns of both the pathogenic fungus and the beetle in the United States. Scientists believe that TCD occurs only on walnut, butternut, and wingnut, but it is most damaging to native black walnuts, Juglans californica, J. hindsii, and J. nigra although the disease has been recorded on at least 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 funguhe news is startling, but not totally unexpected.
Visitors to the UC Statewide Integrated Pest Management Program (UC IPM) display in front of Briggs Hall at the 101st annual Picnic Day last Saturday at the University of California, Davis, got a close look at the Pipevine Swallowtail caterpillar.
While the visitors watched or held them, the other caterpillars kept busy, munching on the leaves of their host plant, the pipevine.
Butterfly expert Art Shapiro, distinguished professor in the UC Davis Department of Evolution and Ecology, has seen lots of Pipevine Swallowtails (Battus philenor) already this year. "There are plenty," he said today. "Don't eat 'em; they're quite poisonous."
Both the caterpillar and the adult are poisonous. The caterpillars of the Pipevine Swallowtail feed on the poisonous host plant, Aristolochia, also known as the pipevine, Dutchman's pipe or birthwort. It contains the lethal toxin aristolochic acid.
Nevertheless, the black caterpillars turn into beautiful adults. Found throughout North America and Central America, they are black with iridescent blue hind wings. Their wingspan can exceed three inches.
"The Pipevine Swallowtail flies from late winter (February-March) to autumn (October, occasionally November) but is much more numerous before the 4th of July than later; typically it has two large flights followed by stragglers the rest of the season, often with a 'blip' upward in August," Shapiro writes on his website. "Usually the host plant stops growing in June, and thereafter there are no sites suitable for egg-laying--unless there is a local catastrophe (usually fire, though weed-whacking will do). Then the plants regenerate rapidly, producing new growth in the off-season, and any females around at the time quickly find and make use of the new shoots. Adults routinely live a month or so."
"This species is warningly colored and inedible to vertebrate predators," Shapiro points out. "It derives its protection from the toxic aristolochic acids produced by the host, which it sequesters; females even pass these along to the eggs, which are also protected (and are brick red, laid in bunches of up to 20, and quite conspicuous)."
"Adults are eager visitors to many flowers, including Wild Radish, California Buckeye, Blue Dicks, Ithuriel's Spear, and Yerba Santa," Shapiro notes. "In summer they regularly nectar at Yellow Star Thistle when there are no native plants in bloom."
We've seen many of the Pipevine Swallowtails fluttering around in the UC Davis Arboretum and gathering nectar from butterfly bushes.
A word of warning from Shapiro: "Don't eat 'em; they're quite poisonous."
His daughter-in-law, Mary Louise “Mary Lou” Flint, a longtime leader of the University of California Statewide Integrated Pest Management (UC IPM) Program and a newly retired Extension entomologist with the UC Davis Department of Entomology and Nematology, will be honored at a dinner on Dec. 1 as the recipient of the 2014 James H. Meyer Distinguished Achievement Award for her outstanding contributions to the university.
The event will take place at 6 p.m., in Ballrooms B and C of the UC Davis Conference Center. Reservations may be made by contacting UC Davis Special Events at (530) 754-2262 by Nov. 24.
Flint, UC IPM's associate director for Urban and Community IPM, and who retired at the end of June, is the third entomologist (Frank Zalom, 2004, and Thomas Leigh, 1988) to receive the Academic Federation award, first presented in 1971.
Her father-in-law, who served as chancellor from 1969 to 1987, during the university's greatest period of growth and change, strongly supported the Academic Federation and the Cooperative Extension Specialists, Agricultural Experiment Station researchers and other non-Senate academics it represents, Flint said.
Parrella said that Flint “has been heavily involved in the leadership, creativity and the success of UC IPM Program since 1983 and is UC IPM's longest-tenured employee. Also since 1983, she has served as an Extension entomologist in our department and we are proud of her innovative ideas, dedication, commitment and accomplishments. Dr. Flint is truly an outstanding leader and visionary who has initiated, conducted and established research, educational and outreach programs that we sometimes take for granted. She advances IPM practices that are economical, environmentally friendly and health conscious.”
Wrote UC IPM Director Kassim Al-Khatib: “Dr. Flint has initiated, conducted, and established an outstanding and well respected IPM research and outreach program for urban and community. Many of her programs and findings have significant impact on pest management in California. She is a talented, capable specialist and good communicator to the IPM end-user.” Globally, the UC IPM program is considered the gold standard of IPM.
Flint received her bachelor's degree in plant sciences in 1972 from UC Davis, and her doctorate in entomology from UC Berkeley in 1979. “We are fortunate that she chose to spend her career here at UC Davis,” Parrella said.
Among her accomplishments:
- Created, wrote or edited and oversaw the development of the UC IPM's IPM Manual series of books from 1980-2007; this series includes IPM manuals on 15 different agricultural crops or crop groups. More than 100,000 copies of these books have been sold worldwide.
- Oversaw the development and creation of the online UC IPM Pest Management Guidelines from 1987-2007. This series included 43-crop specific PMGs featuring hundreds of pests and thousands of photographs and authored by UC experts around the state and updated regularly. Flint served as technical editor. She developed many online tools associated with the PMGs such as the Natural Enemies Gallery and the Weed Galleries.
- Established the UC IPM Pest Note series for home, garden, landscape and urban audiences. This series covers more than 165 pests. About 12,000 people a day access these publications on the UC IPM Home and Garden website.
- Authored several important books on IPM including Pests of the Garden and Small Farm, IPM in Practice: Principles and Methods of IPM and The Natural Enemies Handbook. She developed the Pesticide Compendium series along with Patrick O'Connor Marer.
- Created some of the earliest interactive learning tools of IPM, including the 1996 CD-ROM Solving Garden Problems: A University of California Interactive Guide and The UC Interactive Tutorial for Biological Control of Insects and Mites (an interactive CD-ROM, Publication 3412). She and her colleagues also created some of the first online training materials for IPM with online training programs for retail nursery and garden center personnel. The UC Guide to Healthy Lawns on the UC IPM website is another key accomplishment. UC IPM takes its 16 portable UC IPM Touch Screen IPM kiosks to hundreds of retail stores and community events. More recently, Flint has been heavily involved in creating YouTube videos on the UC IPM channel and disseminating information through other electronic and social media.
- Developed hands-on, train-the-trainer programs for UC Master Gardeners, retail nursery personnel and landscape professionals that have resulted in the delivery of information to far more people than would be possible through conventional training meetings. Among the topics: biological control, pesticides and landscape pest identificatio
Lately Flint has been involved with the thousand cankers disease, caused by the walnut twig beetle, Pityophthorus juglandis, in association with the fungus, Geosmithia morbida. The disease kills walnut trees, especially black walnuts. She continues to work on the project with research entomologist Steven J. Seybold of the USDA Forest Service, Pacific Southwest Research Station, Davis, and other scientists.
Seybold, an affiliate of the UC Davis Department of Entomology and Nematology, said that on a national level, Flint was "instrumental in facilitating the rapid processing and release of the national trapping guidelines for the walnut twig beetle."
"Once our team had discovered the aggregation pheromone of this beetle and had demonstrated its value in trapping the insect in California, Mary Louise assisted us with the preparation and dissemination of useful trapping guidelines, which have been employed by state pest regulatory officials and detection entomologists throughout the country.”
Widely honored by her peers, Flint received the 2002 Outstanding Lifetime Achievement Award for Integrated Pest Management from the Association of Applied IPM Ecologists; a 2003 IPM Innovator Award from the California Department of Pesticide Regulation as part of the Sacramento Water Wise Pest Control Program; a 2003 resolution from the Sacramento City Council honoring her for contributions to the Sacramento Water Wise Program; a 2004 Environmental Services Award from the San Francisco Department of the Environment; and an international IPM Award of Recognition, “Grower Incentives Team Project,” at the 2009 International IPM Symposium in Portland, Ore.
Flint is not only the third entomologist to receive the award, but the third IPM specialist. Frank Zalom, a distinguished professor in the UC Davis Department of Entomology and Nematology, directed the UC IPM Program for 16 years (1988-2001). He is currently serving as president of the 7000-member Entomological Society of America. Thomas Leigh (1923-1993) stood at the forefront of integrated pest management of cotton pests, according to an article in the summer 1994 edition of American Entomologist. He taught courses on cotton IPM and host plant resistance.