- Author: Kathy Keatley Garvey
Chemical ecologist Elvira Simone de Lange, a postdoctoral researcher in the Christian Nansen lab, UC Davis Department of Entomology and Nematology, has received a three-year $249,878 federal grant that involves using drones to detect the early infestation of spider mites, and then targeting the pests with biocontrol agents.
The grant is from the U.S. Department of Agriculture's Western Sustainable Agriculture Research and Education (SARE) Program.
Her research project, "Unmanned Aerial System (UAS)-Guided Releases of Predatory Mites for Management of Spider Mites in Strawberry," aims to identify “very subtle differences in reflectance of the strawberry canopy, indicating spider mite-induced stress,” she said. “Releasing predatory mites in these spider mite hotspots will increase their efficacy as biocontrol agents, enhancing sustainability of spider mite management practices in strawberry.”
In her successfully funded proposal, she noted that “Farmers are requesting in-depth testing of how UAS can be integrated successfully into strawberry production to improve management practices.” UAS, or drones, can monitor large areas in a short period of time. California produces 88 percent of the nation's strawberries, with an annual value of approximately $2.6 billion.
The three-year project, now underway through March 2020, also explores the use of drones as a novel, effective way of distributing the predatory mites.
The grant also calls for educational outreach programs, with hands-on workshops and lectures on spider mite sampling at grower and agriculture professional meetings throughout the California strawberry growing region. Growers outside this area will be reached through publications in trade journals and other grower media.
Multiple species of spider mites infest the state's strawberry fields. The twospotted spider mite, Tetranychus urticae, an annual pest of strawberries in all growing regions, is the predominant species in strawberries grown on the Central Coast, according to the UC Statewide Integrated Pest Management Program's Pest Management Guidelines (PMG), written by lead author and IPM specialist Frank Zalom, distinguished professor of entomology, UC Davis Department of Entomology and Nematology.
The mites suck plant juices. The damage can result in decreased fruit size and yield. Mite-feeding symptoms include dense webbing, and dry, brittle and discolored leaves.
“Twospotted spider mite feeding is particularly damaging during the first two to five months following transplanting in late summer or fall,” according to the PMG.
A native of The Netherlands, de Lange joined the Nansen lab in March 2016. She received her bachelor's degree in biology, and her master's degree in plant biology from Utrecht University, The Netherlands. She earned her doctorate in chemical ecology from the University of Neuchâtel, Switzerland. Her first postdoctoral position was at Rutgers University, New Jersey, where she worked on insect resistance in cranberries.
Overall, she hopes her research meshing chemical ecology, entomology, plant-arthropod interactions and biological control in the fields of integrated pest management and precision agriculture solutions, will “lead to the development of novel, sustainable pest management practices.”
- Author: Kathy Keatley Garvey
A noted entomologist and biological control specialist, Dr. Ehler was the first biological control specialist on campus and was known as the “quintessential biological control researcher.
"Dr. Ehler had a remarkable career at UC Davis,” said Steve Nadler, professor and chair of the UC Davis Department of Entomology and Nematology. “In his research he built upon fundamental investigations in integrated pest management (IPM) to provide practical biological control for many different systems. Les was both a national leader in the discipline of biological control, and an outstanding citizen of the department and university.”
For four decades Dr. Ehler championed the use of natural enemies to control agricultural pests and warned of the dangers of pesticides.
he co-edited the 1990 book, Critical Issues in Biological Control and served four years as president and four years as past president of the International Organization for Biological Control. He also chaired the Entomological Society of America's Biological Control Section.
Born Jan. 6, 1946 in Lubbock County, Texas and reared on a family farm near the small town of Idalou, Les Ehler received his bachelor's degree in entomology from Texas Tech University, and his doctorate in entomology from UC Berkeley. He joined the UC Davis faculty in 1973 as an assistant professor, advancing in 1985 to professor of entomology and entomologist in the UC Davis Experiment Station. He retired as an emeritus professor in 2008.
Coordinating the memorial is his son, Brian Ehler of Susanville, assisted by close friend and colleague Harry Kaya, emeritus professor, UC Davis Department of Entomology and Nematology.
The lodge is located off Garrod Drive. For more information, contact Brian Ehler at brian_ehler@yahoo.com or Harry Kaya at hkkaya@ucdavis.edu. (Visitor parking lot)
The UC Davis Department of Entomology and Nematology posted a tribute to Dr. Ehler at http://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=22031
- Author: Kathy Keatley Garvey
"Dr. Ehler had a remarkable career at UC Davis,” said Steve Nadler, professor and chair of the UC Davis Department of Entomology and Nematology. “In his research he built upon fundamental investigations in integrated pest management (IPM) to provide practical biological control for many different systems. Les was both a national leader in the discipline of biological control, and an outstanding citizen of the department and university.”
Dr. Ehler, who joined the UC Davis Department of Entomology in 1973 and retired in January 2008, was the first biological control specialist on campus and was known as the “quintessential biological control researcher.”
For four decades he championed the use of natural enemies to control agricultural pests and warned of the dangers of pesticides.
Dr. Ehler co-edited the 1990 book, Critical Issues in Biological Control and served four years as president and four years as past president of the International Organization for Biological Control. He also chaired the Entomological Society of America's Biological Control Section.
At UC Davis, Dr. Ehler battled pests such as obscure scale and aphids on oaks, stink bugs on tomato, aphids on sugar beet and white fir, and beet armyworm on alfalfa and sugar beet. His expertise ranges from the theory and practice of biological control to the ecology and management of insects and mites in natural, agricultural and urban environments.
“Les was a meticulous researcher and an excellent applied field ecologist,” said colleague and close friend Extension entomologist Larry Godfrey of the UC Davis Department of Entomology and Entomology. “When he took on a research project, you were confident the project would be conducted well and all aspects of the system considered. He made major contributions to our understanding of stink bug ecology and biological control of stink bugs. Les was also excellent at transferring his knowledge via classroom teaching.”
In the late 1990s, Dr. Ehler discovered that pill bugs, also known as roly-poly bugs, prey on the eggs of stink bugs. Up to then, most entomologists classified pill bugs as strictly vegetarians. Stink bugs, major agricultural pests, suck the juices from legume and brassica seeds and fruit of other crops.
In the early 1980s, Dr. Ehler led the Davis team that documented the environmental impact of malathion-bait sprays used to eradicate the Mediterranean fruit fly. The organophosphate was credited with killing the medfly, but also beneficial insects such as honey bees, and natural enemies of various insect pests.
In one study, Dr. Ehler assessed the non-target effects of malathion in the Bay Area. His studies in Woodside, a San Mateo County community on the San Francisco Peninsula, revealed that populations of a native gall midge exploded 90 times the normal level. Ehler compared the gall midge population in Woodside -- where planes sprayed up to 24 malathion applications -- to the untouched Jasper Ridge Biological Preserve near Stanford University. The gall midge is a gnatlike insect pest that lays its eggs in plants; the burrowing larvae form galls.
Dr. Ehler also helped organic farmers solve problems. He designed a stink bug management program for Yolo County organic farmer Robert Ramming of Pacific Star Gardens after learning of the stink bug invasion in his tomato fields.
“The stink bugs were overwintering in his backyard and in the spring, emerging to dine on mustard and then tomatoes,” Dr. Ehler noted in the feature story. “Stink bugs don't seem to prefer tomatoes — they like mustard and wild radish — but when these hosts were plowed under and no longer available, the bugs went for the tomatoes.” Solution: Don't cut the mustard. Plow it under only when the stink bugs aren't a threat to the tomatoes — that is, before they develop wings and disperse.
Quotes from the January 2008 feature story:
- Yolo County organic farmer Robert Ramming of Pacific Star Gardens: “Les determined what stink bugs prefer, their habitat and where they were overwintering. “We planted a five-foot strip of ‘trap' or ‘bribe' crops (mustard and wild radish) around the tomato fields and got rid of 90 percent of the stink bugs.”
- Rachael Long, a UC Cooperative Extension farm advisor in Yolo, Solano, Sacramento counties: “I greatly admire Les for his contributions to IPM that have helped us better understand the biology of some of our major agricultural pests and how to manage them. Les is one of those extraordinary field researchers with a broad knowledge of entomology that make him a great resource for information. In collaborating with Les on various projects I have a much better understanding on how landscapes impact IPM in cropping systems which I believe will help conservation efforts and improve pest control in our agricultural systems.”
- Chemical ecologist Walter Leal, then professor and chair of the UC Davis Department of Entomology: “Les began teaching biocontrol classes for our department in 1974, drawing hundreds of students. He was trained in the 1960s by the founders of integrated pest management (IPM) and he advocated biological control methods as an important IPM pest control strategy. His work led to a better understanding of how predators and parasites can control pests without pesticides.”
- Entomologist Michael Parrella, then associate dean of agricultural sciences in the College of Agricultural and Environmental Sciences: “Les was the first faculty member hired in the Department of Entomology to teach and advance the science and practice of biological control. Trained in classical biological control at UC Berkeley, he was the heart and soul of biological control at UC Davis, and worked in many biological systems from tomatoes to urban landscapes. For many years, Les maintained his own USDA-certified quarantine laboratory which allowed him to work with biological control agents from all over the world. He was a meticulous researcher who maintained a ‘hands-on' approach with all the projects done in his laboratory and he trained many students who are now leaders in the field of biological control around the world.”
Emeritus professor Harry Kaya of the UC Davis Department of Entomology and Nematology said of his close friend and colleague:
"Les and I overlapped as graduate students at UC Berkeley and I have known him for over 45 years. We were reunited as faculty members at UC Davis when I joined the department in 1976. Les was the quintessential entomologist specializing in classical biological control. His research was always thorough and complete and others have commented on his many contributions to the discipline. We co-taught a class on biological control for many years; he covered the theory and application of parasitoids and predators and I did the lectures on pathogens. Les made sure that the students understood the basis for the theoretical aspects of biological control and their application in the field. In the laboratory portion of the class, he took the students into the field to show them biological control agents in action and developed a useful pictorial handout for identifying the common parasitoids and predators found in California. Even in retirement, he assisted farmers in dealing with the stink bug problems in tomatoes."
"Les was the most organized person that I know. Everything in his research lab and office and home had a place and was neatly and logically organized," Kaya noted. "A few years before he retired, he had a plan on what he wanted to do and purchased a fishing boat. The first time we went out, it was clearly a case of the blind leading the blind. We lost more fishing gear without getting a single bite. Les did not see this as a setback, but as a learning experience. He went fishing with professional guides, learned from them, and became an excellent fisherman. He not only took me but many others fishing for striped bass in the Delta, salmon and striped bass in the Sacramento River, and trout, bass, and kokanee at Lake Berryessa."
"I have lost a good friend and colleague. I will miss the many entomological and other stories and his sense of humor we shared on our fishing trips."
Born Jan. 6, 1946 in Lubbock County, Texas and reared on a family farm near the small town of Idalou, Les Ehler received his bachelor's degree in entomology from Texas Tech University, and his doctorate in entomology from UC Berkeley. He joined UC Davis in 1973 as an assistant professor, advancing in 1985 to professor of entomology and entomologist in the UC Davis Experiment Station. Dr. Ehler was an avid fisherman and enjoyed fishing, particularly for sturgeon and salmon.
He is survived by his son Brian of Susanville, Calif., and daughter Mary Ehler Yung and husband, Eric, of Sacramento, and granddaughters Emma Yung and Georgiana Grace Yung. He was preceded in death by his parents, brother Joseph, and sister Loretta. He is survived by brothers Eugene (Mary) of Denton, TX, Howard (Rita) of Midland, TX and sisters Jan Chapman (Carl) of Houston, TX and Amy Willingham of Irving, TX. He is also survived by numerous nieces and nephews.
- Author: Kathy Keatley Garvey
His seminar is from 12:10 to 1 p.m. in 122 Briggs Hall. Host is Michael Parrella, professor and chair of the department.
Gillespie's abstract: "The phenomenon of global climate change (GCC) is likely to have a dominant impact on agriculture, food supply and food security in the coming decades. The two dominant GCC trends – increased carbon dioxide concentrations, and increased average annual temperatures, will cause changes in how and where crop plants grow. However, because arthropods are mostly cold-blooded, the underlying effect of GCC on average temperature and temperature ranges within growing seasons is likely to be of greater importance for IPM in agriculture. Biological control of pest insects by arthropod natural enemies is an integral part of IPM. The benefits derived from biological control (increased yields and reduced pest numbers) are governed by the principles of population and community ecology. Relationships between species in biological control, such as prey-predator dynamics, competition and trophic cascades are driven in part by rates of growth and movement of the component species, which are in turn governed in part by temperature."
"This seminar presentation will summarize some recent work on the effects of extreme temperatures on an experimental biological control community. I will conclude by presenting some preliminary results from work-in-progress which places the effects of extreme temperatures in the context of the two key GCC trends: carbon dioxide and average growing season temperature."
Gillespie says he's primarily an insect ecologist and biological control scientist. "For over 30 years the focus of my research has been the development and introduction of biological control agents and biological control systems for use in Canadian greenhouse crops. Many of the predators and parasitoids that I have developed as biological control agents are currently produced and sold in Canada, and are used extensively to replace insecticide use in greenhouse and other crops. The principles of population and community ecology are used to develop approaches to limit insect population growth in order to reduce or eliminate insecticide applications while maintaining productivity, crop quality and profitability. The results help to develop IPM systems in crops, and improve worker and environmental health."
His current research projects entail classical biological control programs for pests of canola and other cole crops; development of life table models for spotted wing drosophila; surveys of egg parasitoids of Pentatomidae; and development of an improved understanding of the effects of extreme temperature events and other climate change factors biological control communities. This last work led to participation in a report on the effects of climate change on invertebrate genetic resources in Agriculture for the FAO."
Gillespie also is an adjunct professor in the Department of Biological Sciences at Simon Fraser University where he has co-supervised numerous master's degree and Ph.D. students. He served on supervisory committees for M.Sc. and Ph.D. students at Cornell University, University of British Columbia, and the University of Windsor. His contributions have been recognized by an honorary membership in the International Organization for Biological Control (2012), an AAFC Gold Harvest Award (2011), by a lifetime achievement award from the Professional Pest Management Association of British Columbia (2011), and an Award of Excellence from Association of Natural Biological Control Producers (2003)
Assistant professor Brian Johnson is coordinating the winter quarter seminars. Plans call for recording the seminars for later posting on UCTV.
- Author: Kathy Keatley Garvey
His seminar is from 4:10 to 5 p.m. in 122 Briggs Hall. His host is Professor Jay Rosenheim, his former major professor. (Editor's note: This is a time change due to midwest storms delaying his flight)
An abstract of Heimpel's talk:
"Over the past 25 years or so, importation ('classical') biological control of arthropod pests has undergone a paradigm shift in which emphasis has shifted from an exclusive focus on efficacy to a focus on the actual and potential risks of biological control introductions. Host specificity testing is the cornerstone of risk assessment in this new paradigm, and only highly specialized agents are currently approved for release."
"Here, I describe the process of importation biological control of an invasive agricultural pest in the North-Central U.S. - the Asian soybean aphid. Numerous parasitoid species were imported from Asia as potential biological control agents and I focus on 5 species for which host-specificity testing was done. Each of these five species tells a different story in terms of host-specificity, the potential for biological control efficacy, and actual success of field releases. Together, these case studies illustrate some potential relationships between safety and efficacy in biological control, and the importance of various traits in mediating safety and efficacy of biological control agents."
Born in Germany, Heimpel grew up mainly in California. He received his bachelor’s degree in conservation and resource studies in 1988 from UC Berkeley; his master's degree in 1991 in entomology and applied ecology from the University of Delaware; and his doctorate in 1995 from UC Davis, where he was advised by Jay Rosenheim. Heimpel then spent two years as a USDA post-doctoral fellow at the University of Wisconsin in Mike Strand’s lab.
At the University of Minnesota, Heimpel focuses his research in the fields of biological control and parasitoid ecology. Most of this work has been done in agricultural settings, and has included investigations of sugar-feeding by parasitoids in the field and implications for conservation biological control, biological control of soybean aphid and genetics of sex determination in parasitic hymenoptera. More recent projects have incorporated a conservation focus however, including investigations of an invasive fly species in the Galapagos Islands. Heimpel teaches biological control and insect behavior.
On his website, Heimpel says: “Most of the projects in my lab focus on host-parasitoid interactions and biological control. Investigations range from genetics to community ecology with an emphasis on behavioral, population and evolutionary ecology of parasitoids within the context of biological control. Current projects include classical and conservation biological control of the soybean aphid in the United States, classical biological control of a parasite of Darwin’s finches in the Galapagos Islands, and classical biological control of the imported cabbageworm in the United States.”
“More generally, interests in the lab focus on aspects of host specificity in parasitoids, indirect interactions in natural and agricultural systems, sex determination in parasitoid wasps, evolution of parasitoid reproductive strategies, and ecosystem services (biological control) associated with biofuel cropping systems.”
Plans call for the seminar to be recorded for later posting on UCTV. Coordinating the fall seminars are assistant professors Brian Johnson and Joanna Chiu.
Heimpel's recent publications include:
Hopper, K. R., S. M. Prager, and G. E. Heimpel. 2013. Is parasitoid acceptance of different host species dynamic? Functional Ecology 27:1201-1211.
Heimpel, G. E., Y. Yang, J. Hill, and D. W. Ragsdale. 2013. Environmental consequences of invasive species: greenhouse gas emissions of insecticide use and the role of biological control in reducing emissions. PLoS One 8:e72293.
Wulff, J. A., K. Buckman, K. Wu, G. E. Heimpel, and J. A. White. 2013. The endosymbiont Arsenophonus is widespread in soybean aphid, Aphis glycines, but does not provide protection against parasitoids or a fungal pathogen. PLoS One 8:e62145.
Chacon, J. M., M. K. Asplen, and G. E. Heimpel. 2012. Combined effects of host-plant resistance and intraguild predation on the soybean aphid parasitoid Binodoxys communis in the field. Biological Control 60:16-25.
de Boer, J. G., B. Kuijper, G. E. Heimpel, and L. W. Beukeboom. 2012. Sex determination meltdown upon biological control introduction of the parasitoid Cotesia rubecula? Evolutionary Applications 5:444-454.
Desneux, N., R. Blahnik, C. J. Delebeque, and G. E. Heimpel. 2012. Host phylogeny and specialisation in parasitoids. Ecology Letters 15:453-460.
