Cooperative Extension agricultural specialist Ian Grettenberger, assistant professor, UC Davis Department of Entomology and Nematology, and his graduate student, Madison "Madi" Hendrick, will discuss the crops, the pests, and the natural enemies or beneficials at a virtual Facebook live session from 11 a.m. to noon, Thursday, Oct 22.
The event, "The Good and the Bad: Insects and Other Arthropods in Agriculture, with a Focus on California Rice and Alfalfa," will be live-streamed on the UC Davis Bohart Museum of Entomology's Facebook page. (Link to Facebook live here). Grettenberger and Hendrick will present short talks and then field questions. No personal Facebook account is required to join the session, which is free and open to the public.
"This is all about the arthropods, both the pests and beneficials that they study in the rice and alfalfa fields," said Tabatha Yang, education and outreach coordinator for the Bohart Museum of Entomology. "Most of the focus is on insects, but tadpole shrimp in rice fields also will be discussed." A virtual family craft activity is also planned.
"I will be discussing some of the insect (or arthropod) problems faced by growers of rice in California and some of the challenges in managing them, Grettenberger said. "In rice, some of the key arthropod pests are tadpole shrimp, which can turn what would have been a lush stand if rice into a poor stand with a lot of floating seedlings. Meanwhile, later in the year, armyworm caterpillars, the larvae of a moth, can chew on rice leaves and destroy plants. I'll discuss some of the ongoing work to better understand and manage these pests."
Grettenberg's fields of expertise include field and vegetable crops; integrated pest management; applied insect ecology, and biological control of pests. (See Spotlight on Ian Grettenberger.) Among his current grants:
- Protection of rice from invertebrate pests
- Insecticide resistant alfalfa weevils in the western United States: Quantifying the scope of resistance and implementing a plan to manage the threat
- Management of key cotton arthropod pests with insecticides and acaricides, a proactive approach to prepare for the invasion of the tomato leafminer (Tuta absoluta) into California
- Detection, biology and control of the exotic Swede midge (Contarinia nasturtii) for California cole crops
- Management of the western spotted and striped cucumber beetle in melon production
- Biological control of the bagrada bug
- Insecticide resistance monitoring and evaluation of efficacy of current chemical tactics for managing aphids and thrips in lettuce
What sparked his interest in entomology? "I had biologist parents, and was drawn into entomology at a pretty young age," Grettenberger said. "I spent plenty of time looking in flowers and turning over logs looking for insects. Once I started thinking about going to graduate school for entomology, I decided to focus on the intersection of agricultural entomology and insect ecology. I wanted to work on applied issues in entomology."
Hendrick, a second-year graduate student in the Grettenberger lab, received her bachelor's degree in iInternational studies at North Carolina State University, and also spent a semester at Nagoya University in Japan (she minored in Japanese).
"I got my start in entomology completely by chance!," Hendrick related. "I needed a science credit and happened to pick a class called 'Insects and People.”' That class really helped me to reframe the way I thought about insects and appreciate what interesting little critters they are. Through that class, I was also able to get a job as an undergraduate assistant in an entomology lab. I worked in a specialty crops lab, where I developed interests in integrated pest management and invasive species. I now study insecticide resistance in the alfalfa weevil, and I'm excited to share what I've learned through this outreach event!"
Grettenberger, Yolo County Farm Advisor Rachael Freeman Long and Madi Hendrick recently wrote a piece in the UC Agricultural and Natural Resources (UC ANR) blog, Alfalfa and Forage News, "A (Virtual )Update on Worms, Weevils an Aphids in Alfalfa."
"This year, the Kearney Research and Extension Center Alfalfa and Forage Field Day went virtual," Grettenberger wrote. "Attendees did not get the chance to look out over lush fields of alfalfa or towering plantings of sorghum, but they get did an update on ongoing work in alfalfa and other forages. Our team put together a rapid-fire video to discuss what are typically the key insect pests in California alfalfa: summer worms, alfalfa weevils, and aphids."
The summer worms in alfalfa include the summer worms: Western yellowstriped armyworm, beet armyworm and alfalfa caterpillar. Another key pest is the alfalfa weevil. The trio also discussed aphids and their natural enemies, including lady beetles, aka ladybugs).
Pests of rice include armyworms, aster leafhoppers, crayfish, rice leafminers, rice seed midges, rice water weevils and tadpole shrimp.
The Bohart Museum, directed by Lynn Kimsey, UC Davis professor of entomology, is located in Room 1124 of the Academic Surge Building on Crocker Lane, UC Davis campus, but is temporarily closed. The museum houses nearly eight million insect specimens; a live "petting zoo" of Madagascar hissing cockroaches, walking sticks and taranatulas; and a gift shop stocked with insect-themed T-shirts, books, posters, jewelry, candy and insect-collecting equipment.
- Alfalfa and Forage News: A (Virtual) Update on Worms, Weevils and Aphids in Alfalfa (By Ian Grettenberger, Rachael Freeman Long and Madi Hendrick, Sept. 20, 2020) (See video on same page)
- Alfalfa and Forage News: Natural Enemies Are Important for Control of the Aphid Complex in Alfalfa--A Case Study (By Ian Grettenberger, Rachael Freeman Long, Daniel Putnam and Rob Wilson, April 7, 2020)
- UC Statewide Integrated Pest Management Program: How to Manage Pests of Alfalfa
- UC Statewide Integrated Pest Management Program: Insects and Other Pests of Rice
James R. Carey, UC Davis distinguished professor of entomology, will share his scientific modeling expertise at the UC Davis-based COVID-19 webinar on Thursday afternoon, April 23.
The webinar, to be broadcast on Zoom and YouTube Live from 1:30 to 4 p.m., will feature physicians, scientists and a survivor of the COVID-19 virus, announced organizer-moderator Walter Leal, UC Davis distinguished professor of the Department of Molecular and Cellular Biology and a fellow of the National Academy of Inventors.
“COVID-19 is set apart from all other strains of flu for the simple reason that people die from it at higher rates than from other varieties,” Carey says. “It follows that understanding the actuarial details and consequences of this virus is central to understanding, has potential impact on the U.S. population in particular and on the world population in general.”
In his presentation, Carey will ask and answer three questions: “The first is related to case fatality rate of COVID-19. The second concern will be the age-specific mortality of this virus, and the third, to its demographic consequences if no health-related interventions, policies implemented, or a vaccine were available.” Carey is the co-author of the newly published book, Biodemography: An Introduction to Concepts and Methods. (See news story.)
The webinar, free and open to the public, will include experts in immunology, infectious diseases, pathology and emergency medicine. Registration is at http://zoompresentation.com. The number of Zoom participants is limited to 500, and is now at that mark, Leal said late Wednesday afternoon, but the overflow can watch it on YouTube Live at at covidactionplan.com or https://bit.ly/2VurK3Z.
Chancellor Gary May will give the introduction. The main speakers are UC Davis physician-scientists Emanuel Maverakis, Stuart Cohen and Nathan Kuppermann; UC Davis veterinarian-scientist Nicole Baumgarth; physician Ron Chapman, Yolo County Health Officer; and pediatrician State Sen. Richard Pan, District 6 chair, Senate Committee on Health.
Davis resident Marilyn Stebbins, a pharmacist who works at the UC San Francisco School of Pharmacy--and a survivor of the deadly illness that to date has killed more than 182,000 people worldwide (15,000-plus in the United States)--will tell her story. (See Johns Hopkins University's coronavirus map for up-to-date statistics.)
You-Lo Hsieh, UC Davis distinguished professor in the Department of Biological and Agricultural Engineering, and an expert on textiles and clothing, will explain the differences between regular masks, surgical masks, and N95 masks.
Newly added to the list: Michael B. A. Oldstone, M.D., of Scripps Research Institute; professor emeritus Niels Pedersen, DMV, of UC Davis School of Veterinary Medicine, and Anne Wyllie, PhD., Yale School of Medicine.
The participants will answer advance and online questions. Questions can be submitted at this site: http://zoompresentation.com.
Martin Hauser, senior insect biosystematist with the Plant Pest Diagnostics Center, California Department of Food and Agriculture (CDFA), will speak on “The Curious Case of the Stingless Bees of Palo Alto” at the Pacific Coast Entomological Society meeting on Thursday, Feb. 27 on the UC Davis campus.
The society will meet at 7:30 p.m. in the conference room of the Museum of Wildlife and Fish Biology, Room 1371 of the Academic Surge Building on Crocker Lane.
“In 2013 we found a stingless bee colony in Palo Alto in a tree,” Hauser said, “and I had a very hard time identifying the species—the genus is Plebeia—and I had no idea how they made it into California and where they came from. Many years later and many strange events later, I figured all these things out.”
Hauser will discuss his research and also reveal how long stingless bees have been sighted in California. It is illegal to import stingless bees into the United States.
The 7:30 p.m. meeting begins with a general business session, followed by Hauser's talk. All interested persons are invited to attend.
A pre-meeting dinner will begin at 6 p.m. at the KetMoRee restaurant in downtown Davis. Members and entomology associates interested in joining the group for dinner should email Kady Tauber at email@example.com before Tuesday, Feb. 25.
The society meets six to eight times a year, usually at the California Academy of Sciences, UC Berkeley, or at the CDFA's Plant Pest Diagnostics Center. Membership in the society, organized in 1901, is open to everyone--amateurs and professionals alike. The annual membership fee is $25, and $12.50 for students. The society publishes the quarterly journal, The Pan-Pacific Entomologist. and the Bits and PES Newsletter for members residing within commuting distance of San Francisco.
The Beer-for-a-Butterfly Contest is not over.
Art Shapiro, UC Davis distinguished professor of evolution and ecology who annually sponsors the contest in the three-county area of Sacramento, Solano and Yolo to determine the first flight of the cabbage white butterfly, sighted one on Thursday, Jan. 30 at the Putah Creek Nature Park, Winters, Yolo County, but did not collect it.
He spotted the butterfly, Pieris rapae, basking on a malva leaf at 11:16 a.m., but it took off before he could net it.
Shapiro says that since he didn't collect it—no collection, no voucher—the contest is still underway. The prize always goes to the first person who collects the first cabbage white of the year.
"Now that I know the bug is out, there's no scientific reason to want more records," he wrote in a email. "To be fair to potential competitors, the first person to catch a rapae in the contest area before 5 p.m., Sunday, Feb. 2, wins the beer. I will not try to beat them to a voucher." Shapiro says this was the latest first flight date for Valley rapae since Jan. 31, 2011,
Shapiro collected the 2019 winner on Jan. 25 near the Suisun Yacht Club, Solano County. Since 1972, when he launched the contest, the first flight has varied from Jan. 1 to Feb. 22, averaging about Jan. 20. The rules are here: https://bit.ly/2GE5coY
The contest rules include:
- It must be an adult (no caterpillars or pupae) and be captured outdoors.
- It must be delivered alive to the department office, 2320 Storer Hall, UC Davis, during work hours, 8 a.m. to 5 p.m., Monday through Friday, with the full data (exact time, date and location of the capture) and your name, address, phone number and/or e-mail. The receptionist will certify that it is alive and refrigerate it. (If you collect it on a weekend or holiday, keep it in a refrigerator; do not freeze. A few days in the fridge will not harm it, Shapiro says.)
- Shapiro is the sole judge.
The UC Davis professor has monitored butterfly population trends on a transect across central California since 1972 and records the information on his research website. His 10 sites stretch from the Sacramento River Delta through the Sacramento Valley and Sierra Nevada mountains to the high desert of the Western Great Basin. He visits his sites every two weeks "to record what's out" from spring to fall, weather permitting. He has studied more than 160 species of butterflies in his transect. The largest and oldest database in North America, it was recently cited by British conservation biologist Chris Thomas in a worldwide study of insect biomass.
The nine-member research team, led by Frank Schroeder, a BTI professor and also a professor in Cornell University's Department of Chemistry and Chemical Biology, detailed how plants speak “roundworm language” for self-defense. The work is published Jan. 10 in the journal Nature Communications.
The researchers studied chemicals called ascarosides, which the worms produce and secrete to communicate with each other. Williamson helped analyze the data and helped make some key insights toward the paper's conclusions, the BTI scientists related.
The team found that plants “talk” to nematodes by metabolizing ascarosides and secreting the metabolites back into the soil.
“It's not only that the plant can ‘sense' or ‘smell' a nematode,” Schroeder said in a BTI news release. “It's that the plant learns a foreign language, and then broadcasts something in that language to spread propaganda that ‘this is a bad place.' Plants mess with nematodes' communications system to drive them away.”
The study built on the team's previous work showing that plants react to ascr#18 – the predominant ascaroside secreted by plant-infecting nematodes – by bolstering their own immune defenses, thereby protecting them against many types of pests and pathogens.
In those earlier studies, “We also saw that when ascr#18 was given to plants, the chemical disappears over time,” according to lead author Murli Manohar, a senior research associate at BTI.
That observation, along with published literature suggesting plants could modify pest metabolites, led the team to hypothesize that “plants and nematodes interact via small molecule signaling and alter one another's messages,” Schroeder said.
To probe that idea, the team treated three plant species – Arabidopsis, wheat and tomato – with ascr#18 and compared compounds found in treated and untreated plants. They identified three ascr#18 metabolites, the most abundant of which was ascr#9.
The researchers also found Arabidopsis and tomato roots secreted the three metabolites into the soil, and that a mixture of 90% ascr#9 and 10% ascr#18 added to the soil steered nematodes away from the plant's roots, thereby reducing infection.
The team hypothesized that nematodes in the soil perceive the mixture as a signal, sent by plants already infected with nematodes, to “go away” and prevent overpopulation of a single plant. Worms may have evolved to hijack plant metabolism to send this signal. Plants, in turn, may have evolved to tamper with the signal to appear as heavily infected as possible, thereby fooling would-be invaders.
“This is a dimension of their relationship that no one has seen before,” said Manohar. “And plants may have similar types of chemical communication with other pests.”
Although the mixture of ascr#9 and ascr#18 could serve as a crop protectant, Schroeder said there should be no detriment to using straight ascr#18 on crops, as described in the team's earlier research.
“Ascr#18 mainly primes the plant to respond more quickly and strongly to a pathogen, rather than fully inducing the defensive response itself,” he said. “So there should be no cost to the plant in terms of reduced growth, yield or other problems.”
The team also showed that plants metabolize ascr#18 via the peroxisomal β-oxidation pathway, a system conserved across many plant species.
“This paper uncovers an ancient interaction,” Schroeder said. “All nematodes make ascarosides, and plants have had millions of years to learn how to manipulate these molecules.”
He added: “Plants aren't passive green things. They are active participants in an interactive dialog with the surrounding environment, and we will continue to decipher this dialog.”
These discoveries are being commercialized by a BTI and Cornell University-based startup company, Ascribe Bioscience, as a family of crop protection products named PhytalixTM.
Scientists affiliated with four institutions--BTI, Cornell, UC Davis and the USDA's Robert W. Holley Center for Agriculture and Health--co-authored the paper. Grants from USDA and the National Institutes of Health funded the research.