The brown planthopper, Nilaparvata lugens, or BPH, is the economically most important rice pest in Asia. It's found only in southeast Asia and Australia, but the methods that a nine-member research team used may be appropriate here in the rice-growing areas of California, says UC Davis agricultural entomologist Christian Nansen, who was part of a nine-member team that just published first-of-its-kind research. It appears in Scientific Reports of the journal Nature.
Using the sustainable pest management method known as "the banker plant system," they did field and laboratory work in China with good results: attracting alternative hosts to parasitoids of rice insect pests, can help protect a rice crop. The players: a grass species, a planthopper, and an egg parasitoid.
Research results showed that BPH densities were significantly lower in the rice fields with the sustainable pest management practice known as the banker plant system compared to control rice fields without the banker plant system, the scientists said.
“Many people are familiar with the concept of a ‘trap crop'-- a sacrificial crop which is planted mixed in with or adjacent to an economically important crop and the trap crop serves to manipulate pests away by offering them a more attractive/suitable host alternative,” said Nansen, an assistant professor with the UC Davis Department of Entomology and Nematology. “The use of banker plants in pest management is similar to the use of trap crops, but banker plants typically have multiple ecological functions.”
The researchers planted a grass species, Leersia sayanuka, next to rice. It attracted a planthopper (Nilaparvata muiri), which does not infest rice.
Rice is the stable food of more than 50 percent of the global population, and 60 percent of the Chinese population. However, scientists concur that the world's rice production needs to increase drastically over the next three decades to meet the growing food demand in Asia. Growing concern over BPH outbreaks and higher pesticide usage led to the sustainable pest management study.
Titled “Use of Banker Plant System for Sustainable Management of the Most Important Insect Pest in Rice Fields in China,” the research is unique in that it is the first published study describing the attraction of alternative hosts to parasitoids of rice insect pests. In rice systems, previously published research involved planting sesame as a nectar source to promote the establishment and persistence of a predatory bug; and studies involving parasitoids.
BPH feeds on the rice crop at all stages of plant growth and can also transmit two viruses, rice ragged stunt virus, and rice grassy stunt virus. Damage can commonly result in a 60 percent yield loss. An infestation is often called “hopper burn,” referring to yellow patches that soon turn brown.
Noting the importance of the banker plant system, Nansen said that banker plants “involve promotion of plant diversity to enhance pest self-regulatory ecosystem functions, such as predation and competition, to reduce susceptibility of agricultural crops to native and invasive pests. Also, banker plants “may provide resources, such as shelter, pollen and nectar or alternative preys to improve the establishment and persistence of beneficial insect populations used to control a specific pest.” The first successful banker plant system, developed in 1977, involved tomato as the banker plant, a parasitoid and a whitefly.
Nansen is affiliated with both UC Davis and the Zhejiang Sustainable Pest and Disease Control, Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou, China.
Co-authors of the research paper include lead author Zhongxian Lu and colleagues Xusong Zheng, Yanhui Lu, Junce Tian, Hongxing Xu, all of the Zhejiang Sustainable Pest and Disease Control; and Pingyang Zhu, Facheng Zhang and Guihua Chen of the Jinhua (China) Plant Protection Station.
The study was jointly supported by the National Key Research and Development Program of China, Zhejiang Key Research and Development Program, and the Special Fund for Agro-scientific Research in the Public Interest.
Research entomologist William Meikle of the Carl Hayden Bee Research Center, Agricultural Research Center, U.S. Department of Agriculture (USDA-ARS) will speak on "Using Continuous Monitoring to Measure Colony-Level Behavior in Social Insects: A Case Study with Honey Bees" when he visits the University of California, Davis, on Wednesday, March 15.
His seminar, open to all interested persons, will take place from 4:10 to 5 p.m. in 122 Briggs Hall, Kleiber Hall Drive.
Meikle, who joined the Carl Hayden Bee Research Center in 2012, conducts research on continuous monitoring of weight, temperature, humidity, CO2 concentration, and other parameters in honey bee colonies, linking those data with bee colony growth and activity. "I am currently involved in investigating how various stressors, including disease incidence, nutritional stress and agrochemical exposure manifest themselves at the colony level," he says.
"Individuals are the fundamental units of the social insect colony and are thus logical subjects for the study of those colonies," Meikle explains in his abstract. "However, such colonies also exhibit emergent properties or behaviors, such as forager traffic and brood nest temperature control in this case honey bee colonies, that can only be measured using colonies or groups of bees."
"Honey bee colonies offer singular opportunities for study because they can be taken apart with little or no adverse effects, and because they are typically stationary and so can easily be fitted with sensors or placed permanently on electronic scales. The resulting continuous sensor data, such as the weight and temperature data we have focused on, provides information on colony behavior and on how colonies respond to changes in the environment. The idea is that once we know how to interpret continuous data, we can then collect continuous data as response variables in manipulative experiments."
Meikle says much of the work "has focused on collecting such data to monitor behavior of honey bee colonies subjected to sublethal concentrations of pesticides. Because colony behaviors depend on the proper functioning and coordination of many individuals, changes in those behaviors may emerge at lower pesticide concentrations than have been found to affect individual biology. Indeed, field and cage studies showed significant effects at pesticide concentrations as low as 5 ppb in sugar syrup."
Meikle received his bachelor's degree in biology from Pomona College, Claremont, in 1982, and his doctorate in entomology from UC Berkeley in 1992. His career took him from UC Berkeley to the West African country of Benin, then to France, then back to the United States--Texas and Arizona.
After earning his doctorate at UC Berkeley, Meikle served as a scientist and postdoctoral fellow from 1992 to 2001 at the International Institute of Tropical Agriculture (IITA), Calavi, Benin, where he developed an ecological and economic framework of stored product systems in West Africa, including population models of important pests (larger grain beetle and maize weevil), natural enemies (including insects and insect pathogens), sequential sampling plans and scouting programs for farmers, and links of pest population dynamics to weather and to local commodity prices.
Two other positions followed:
- 2001-2009: European Biological Control Laboratory, USDA-ARS, Montferrier-sur-Lez, France, where he researched the use of entomopathogens, such as fungi and nematodes, as biological control agents against different pests, including locusts, termites and Varroa mites of honey bees. "We collected naturally occurring entomopathogenic fungi of Varroa mites, including a new species, and evaluated biopesticide formulations," he related.
- 2009-2012: Honey Bee Research Unit, Kika de la Garza Subtropical Agricultural Research Center, USDA-ARS, Weslaco, Texas, where he explored the ecology and population dynamics of small hive beetles, a recently introduced pest of honey bees in the U.S. "I collaborated with other researchers in investigating the biological control of the Asian citrus psyllid and the larger black flour beetle."
Meikle's seminar, hosted by the UC Davis Department of Entomoogy and Nematology, is the last seminar of the winter quarter. Agricultural entomologist Christian Nansen (email@example.com), assistant professor in the department, coordinates the seminars. They are recorded for later viewing on UCTV.
Devoted to research, teaching and public service, he'll speak next week on “Urban Food Production in the Digital Age—Local Empowerment and Sustainability” as part of the UC Davis Community Book Project, which focuses on award-winning writer, activist and academic Raj Patel's work, Stuffed and Starved: The Hidden Battle for the World Food System.
Nansen, an agricutural entomologist with the UC Davis Department of Entomology and Nematology, will deliver his presentation from 12 noon to 1 p.m., Wednesday, Jan. 18 in the Memorial Union's Garrison Room, UC Davis campus.
Sustainable pest management solutions in agricultural systems is a key component of Nansen's research, and he and his team focus on deployment of drones and imaging systems to optimize stress detection of pest outbreaks. In his leisure time, he is converting his back and front yards in Davis "into an urban farming system."
In his Jan. 18 seminar, Nansen will cite several important reasons why urban and suburban citizens "should increase their level of self-sufficiency and resilience when it comes to food production."
In many respects, Nansen is a citizen of the world.
Born and educated in Denmark, Nansen received his master's degree in biology from the University of Copenhagen in 1995 and his doctorate in zoology from the Royal Veterinary and Agricultural University in Denmark in 2000. He accepted positions in Portugal, Benin, United States, UK and Australia before joining the UC Davis Department of Entomology and Nematology in January 2015 as an assistant professor who focuses on insect ecology and remote sensing. His international experience also includes being an international exchange student at the University of Lisbon, Portugal and a visiting professor at Northwest A&F University, Yangling, China.
As part of his undergraduate studies, Nansen took time off to travel to Brazil to write a book about sustainable agriculture in rainforest areas. “In this process," he related, "I learned about the potential of honey bees as both pollinators of crops but also as ‘promoters' more broadly of sustainable agricultural development."
For his doctorate, his interest turned to the larger grain borer, a serious pest of stored maize and dried cassava roots. He wrote his dissertation on “The Spatial Distribution and Potential Hosts of the Larger Grain Borer, Prostephanus truncatus (Horn) (Coleoptera: Bostrichidae), in a forest in Benin, West Africa.” His research involved stored product insect ecology, field trapping with pheromone traps, experimental work on pheromone production, vegetation analysis, satellite image interpretation, laboratory infestation of potential breeding substrates, and histological studies.
Nansen recalled that his childhood exposures to international scientists played a major role in his choice of a career. His father, a professor in veterinary parasitology, entertained many colleagues in the family home. “And my mother cooked the food! This is probably the main reasons why I enjoy both cooking and why my career has been so international.”
“Even though Denmark is a very small country (5 million people),” Nansen said, “it has been at the forefront of agricultural research and production for many decades. And growing up, my father took me on field trips and exposed me to farming systems.” In fact, young Christian earned his weekly allowance in the chicken business: he sold eggs to neighbors.
In an earlier interview, he expressed delight at seeing a “steadily growing appreciation for the origin and quality of the food we eat," noting that "today, in the 21st century, the technologies deployed in modern agriculture are so advanced and similar to the cutting-edge technologies in other fields. Those technologies require skill sets beyond what most people may be aware of. Use of drones, remote sensing, GIS models, mathematical models of weather, crop physiology and soil dynamics, models to optimize input requirements and minimize economic risks, phone apps to optimize applications of agro-chemicals – these are all skill sets and approaches we are using as part of studying food production systems and developing innovative and reliable tools to be used within the agricultural sector.”
On Thursday, Jan. 19, the day after the UC Davis Community Book Project presentation, Nansen will give a seminar on "Droplets of Evolutionary Biology: Theoretical Modeling of Resistance Evolution to Insecticides" from 4:10 to 5:30 p.m. in 100 Hunt Hall as part of the UC Davis Evolution and Ecology winter-quarter seminars.
He is also coordinating the UC Davis Department of Entomology and Nematology's winter seminars. As part of those seminars, he'll speak Wednesday, March 1 from 4:10 to 5 p.m. on "Reflectance Profiling as a Tool to Study Insects and Other Objects" in Room 122, Briggs Hall.
All the presentations are free and open to the public.
From a beneficial insect to pests...
It's good to see the wide diversity of topics in the UC Davis Department of Entomology and Nematology's winter seminar schedule.
Seminar coordinator Christian Nansen, agricultaral entomologist and an assistant professor, has just announced the list of speakers.
The seminars, open to all interested persons, are scheduled on Wednesdays from 4:10 to 5 p.m. beginning Jan. 11 and continuing through March 15 in Room 122 of Briggs Hall, located on Kleiber Hall Drive, UC Davis campus. Plans are to record all the seminars for later viewing on UCTV.
Some seminars are quite technical but all look interesting--especially the one on honey bees. William Meikle, Carl Hayden Bee Research Center, Agricultural Research Center, U.S. Department of Agriculture, will speak March 15 on "Using Continuous Monitoring to Measure Colony-Level Behavior in Social Insects: A Case Study with Honey Bees." Meikle received his doctorate in entomology from UC Berkeley.
A familiar name and face is Kelli Hoover, who received her doctorate in entomology from UC Davis in 1997. Now a professor of entomology at Pennsylvania State University, she'll speak on "Mechanisms of Resistance in Poplar Against the Asian Longhorned Beetle and Its Gut Symbionts" on March 8.
While a grad student at UC Davis, Hoover studied with major professors Bruce Hammock and Sean Duffey (1943-1997). After a one-year postdoctoral position at UC Berkeley, she joined the faculty of the Penn State University Department of Entomology in 1998.
Her research program at Penn State focuses on invasive species, including development of trapping techniques for the Asian longhorned beetle; gut microbial symbionts of the Asian longhorned beetle and hemlock woolly adelgid; functions of key viral genes in transmission of the gypsy moth baculovirus and anti-viral defenses; and biological control of hemlock woolly adelgid.
UC Davis professor Diane Ullman, an expert on flower thrips, will speak Jan. 18 on "Journey into the Microcosm: A Closer Look at the Western Flower Thrips." She describes thrips as tiny insects that pierce and suck fluids from hundreds of species of plants, including tomatoes, grapes, strawberries and soybeans. The pests cause billions of dollars in damage to U.S. agricultural crops as direct pests and in transmitting plant viruses in the genus Tospovirus, such as Tomato spotted wilt virus. “There are 23 additional approved and emerging tospovirus genotypes transmitted by at least 14 thrips species (Thysanoptera: Thripidae),” said Ullman, who has been researching thrips and tospoviruses since 1987.
The seminar schedule:
Wednesday, Jan. 11
Marco Gebiola, postdoctoral fellow, University of Arizona, Tucson
Topic: ""From Embroys to Hybrids: How the Symbiont Cardinium Shapes the Ecology and Evolution of Encarsia Parasitoids"
Wednesday, Jan. 18
Diane Ullman, professor, UC Davis Department of Entomology and Nematology
Topic: "Journey into the Microcosm: A Closer Look at the Western Flower Thrips"
Wednesday, Jan. 25
Sharon Lawler, professor of entomology, and Ph.D candidate Erin Donley, UC Davis Department of Entomology and Nematology
Topic: "Effects of Aquatic Vegetation and Its Management on Aquatic Invertebrates"
Wednesday, Feb. 1
Greg Sword, professor and Charles R. Parencia Chair in Cotton Entomology, Department of Entomology, Texas A&M, College Station
Topic: "Fungal Endophytes Can Mediate Resistance to Insects, Nematodes and Drought in Cotton Agroecosytems"
Wednesday, Feb. 8
Jennifer Thaler, professor, Department of Entomology, Cornell University, Ithaca, N.Y.
Topic: "Tritrophic Interactions and the Ecology of Fear"
Wednesday, Feb. 15
Pedro Miura, assistant professor, Department of Biology, University of Nevada, Reno
Topic: "Age Accumulation of CircRNAs"
Wednesday, Feb. 22
Jared Ali, assistant professor of entomology, Pennsylvania State University, University Park
Topic: "Multi-Trophic Interactions and the Chemical Ecology of Plant Defenses in Above and Below Ground Contexts"
Wednesday, March 1
Christian Nansen, assistant professor, UC Davis Department of Entomology and Nematology
Topic: "Reflectance Profiling as a Tool to Study Insects and Other Objects"
Wednesday, March 8
Kelli Hoover, professor of entomology, Pennsylvania State University, University Park
Topic: "Mechanisms of Resistance in Poplar Against the Asian Longhorned Beetle and Its Gut Symbionts"
Wednesday, March 15
William Meikle, Carl Hayden Bee Research Center, Agricultural Research Center, U.S. Department of Agriculture
Topic: "Using Continuous Monitoring to Measure Colony-Level Behavior in Social Insects: A Case Study with Honey Bees"
You can find out Wednesday, Oct. 12 at a program on "Bees and Climate Change” at the Häagen-Dazs Honey Bee Haven, located on Bee Biology Road, west of the central campus.
The event, set from noon to 1:30 p.m--and free and open to the public--will include a tour and two speeches. Christine Casey, manager of the honey bee haven, will discuss “Climate Change and the Bee Garden," and Robbin Thorp distinguished emeritus professor of entomology, UC Davis Department of Entomology and Nematology, will cover "Effects of Climate Change on Native Bees."
This is part of the 2016-17 Campus Community Book Project, spotlighting Raj Patel's Stuffed and Starved: The Hidden Battle for the World Food System.
The haven, part of the UC Davis Department of Entomology and Nematology, was installed in the fall of 2009 following a generous donation from Häagen-Dazs, known for its premium ice cream. Approximately half of the company's flavors depend on bee pollination.
The Oct. 12th event is part of a series of tours and open houses scheduled the week of Oct. 11-13. Other tours and open houses for Oct. 11-13:
Tuesday, Oct. 11
Exploring Horticulture Innovations
Noon to 1:30 p.m., Horticulture Innovation Lab Demonstration Center
Tour the low-cost, agricultural technologies that UC Davis researchers are using around the world. Edible plant giveaway to the first 20 visitors.
Wednesday, Oct. 12
Student Farm Tour and Harvest
9 to 10:30 a.m., Student Farm
Join the Student Farm for a special tour and harvest demonstration. Campus and community members are all welcome!
Thursday, Oct. 13
Arboretum Edible Campus Project and World Food Day Information Session
Noon to 1:30 p.m., Plant and Environmental Sciences Salad Bowl Garden
Tour the Salad Bowl Garden and learn more about the Arboretum Edible Campus Project in celebration of World Food Day, which will be Sunday, Oct. 16.
Another upcoming event affiliated with the Campus Community Book Project will feature agricultural entomologist Christian Nansen of the UC Davis Department of Entomology and Nematology. He will speak on "Urban Food Production in the Digital Age--Local Empowerment and Sustainability, on Wednesday, Jan. 18 from noon to 1 p.m. in the Memorial Union.
Those are just some of the events calendared for the academic year and showcasing the Campus Community Book Project. See more events here.
The Campus Community Book Project aims to promote dialogue and build community by encouraging diverse members of the campus and surrounding communities to read the same book and attend related events. The book project advances the Office of Campus Community Relations (OCCR) mission to improve both the campus climate and community relations, to foster diversity and to promote equity and inclusiveness.
For more information on the Campus Community Book Project, visit ccbp.ucdavis.edu.