- Author: Kathy Keatley Garvey
The event, titled “Bugs in Ag: What Is Eating Our Crops and What Is Eating Them?” will take place from 1 to 4 p.m. in Room 1124 of the Academic Surge Building on Crocker Lane. It is free and open to the public.
The open house will focus on the expertise of Cooperative Extension specialist Ian Grettenberger of the UC Davis Department of Entomology and Nematology, who researches pests of rice and alfalfa, among other crops. He and postdoctoral fellow Buddhi Achhami of the Grettenberger lab will be displaying tadpole shrimp (crustaceans), alfalfa weevils, aphids and other pests, and will field questions.
Grettenberger will display newly hatched tadpole shrimp. Guests will be able to view the pests under a microscope. He also plans to show small rice plants, which “look like grass in water.”
The family art activity will be to make tadpole shrimp hats or puppets and provide "googly eyes" to imitate the compound eyes and and the naupliar ocellus, according to Tabatha Yang, the Bohart Museum education and outreach coordinator. Tadpole shrimp, from genus of Triops, belong to the order Notostraca (tadpole shrimp). The name Triops originates from two Greek words meaning "three" and "eye.”
The Bohart Museum, directed by Lynn Kimsey, UC Davis distinguished professor of entomology, houses a global collection of eight million insect specimens; a live "petting zoo" comprised of Madagascar hissing cockroaches, walking sticks (stick insects) and tarantulas; and a year-around gift shop (also online) stocked with insect-themed gifts, such as t-shirts, hooded sweatshirts, posters, jewelry, books, puppets, candy and collecting equipment.
The Bohart Museum has been closed to the public for the last two years due to COVID-19 pandemic precautions. The Bohart observed UC Davis Picnic Day by setting up displays in the hallway of the Academic Surge Building. This spring the museum is open to the public, but groups must make reservations and everyone must follow the UC Davis visitor guidelines: https://campusready.ucdavis.edu/visitors?. The museum's "visiting us" page includes more information.
![A shrimp tadpole, pest of rice. (Photo by Ian Grettenberger) A shrimp tadpole, pest of rice. (Photo by Ian Grettenberger)](/blogs/blogcore/blogfiles/90781.jpg)
![An alfalfa weevil, pest of alfalfa. (Photo by Ian Grettenberger) An alfalfa weevil, pest of alfalfa. (Photo by Ian Grettenberger)](/blogs/blogcore/blogfiles/90782.jpg)
![Lygus bug, a pest of cotton. (Photo by Ian Grettenberger) Lygus bug, a pest of cotton. (Photo by Ian Grettenberger)](/blogs/blogcore/blogfiles/90783.jpg)
![An assassin bug in cotton eating a collops beetle. (Photo by Ian Grettenberger) An assassin bug in cotton eating a collops beetle. (Photo by Ian Grettenberger)](/blogs/blogcore/blogfiles/90784.jpg)
![A pea aphid, a pest of alfalfa. (Photo by Ian Grettenberger) A pea aphid, a pest of alfalfa. (Photo by Ian Grettenberger)](/blogs/blogcore/blogfiles/90785.jpg)
![A striped cucumber beetle, a pest found on squash, cucumbers, melon and other crops. (Photo by Ian Grettenberger) A striped cucumber beetle, a pest found on squash, cucumbers, melon and other crops. (Photo by Ian Grettenberger)](/blogs/blogcore/blogfiles/90787.jpg)
- Author: Ian M Grettenberger
- Author: Kevin Goding
- Author: Rob Wilson
During the 2021 season, we conducted an insecticide trial evaluating a new insecticide being developed for a range of crops. It could be a very good fit for alfalfa weevil given the efficacy we saw as well as the critical need for novel modes of action for alfalfa weevil management. The need for more modes of action comes from the growing issue with pyrethroid resistance in alfalfa weevils. Across the US (an in California), there are now populations of pyrethroid-resistant alfalfa weevils. We are addressing this in a separate project, focusing primarily on resistance to lambda-cyhalothrin. New modes of action could allow for rotation, something that is very difficult given that currently, effective options are mainly limited to various pyrethroids or indoxacarb (Steward).
The new material we were focused on was isocycloseram, marketed under the name of Plinazolin technology by Syngenta. This is a group 30 mode of action. Product names are not available yet given where it is at in the registration process and we were working with an experimental formulation at multiple rates. We also evaluated Endigo ZCX (lambda-cyhalothrin + thiamethoxam). These were compared to the current standards of Warrior II (lambda-cyhalothrin) and Steward (indoxacarb).
* Treatments 2-4 are with an experimental formulation, so the chemical name is listed here
This trial was conducted at the Intermountain Research and Extension Center in Tulelake, CA using 27 x 30 ft plots. The plots were managed using standard practices, although the field did not receive additional irrigation due to the water shortage in the Klamath Basin this last year. Applications were made once alfalfa weevil populations had built (I'd insert the average weevil count at 0 DAT here) using a CO2 powered backpack sprayer using a nine-foot handheld spray boom. Applications were made at 20 GPA and 30 PSI with TeeJet XR8002 nozzles. All treatments included Rainier-EA nonionic surfactant-activator-spreader at 0.25% v/v. Alfalfa was 18-in tall and pre-bud at application. Insects were sampled using 10 180° sweeps per plot. Pre-treatment samples were taken from just outside of the plot area (5 locations) to avoid disturbing the plots. Insect samples were taken 0, 7, 10, 14, and 21 DAT. No phytotoxicity was noted.
Alfalfa weevils
We found consistent effects of our treatments across evaluation dates and all insecticide treatments displayed similar efficacy. All treatments kept weevil populations below 2/10 sweeps, equating to at least 97% control for all insecticide treatments through 10 DAT. All treatments kept weevil populations low through 21 DAT as well. While pyrethroid resistance could be an issue in some regions, we did not expect to see that here and did not, with pyrethoid-containing materials working well. Weevil populations were increasing at the time of treatment and then began to decline 14 DAT through 21 DAT.
Effect of treatments on alfalfa weevil larvae populations. In the legend, treatments that do not share a letter are significantly different from one another analyzed across sampling dates (7-21 DAT).
Natural enemies
There were a few different natural enemies within our plots, so we also evaluated the effect of our treatments on these taxa to evaluate “non-target effects.” These included lady beetles, minute pirate bugs, and parasitoid wasps. Of note is that we have a limited suite of treatments, so we were not evaluating some of the other selective materials used in alfalfa like those that would tend to be used for aphids.
First, we have the lady beetles. These were primarily the seven-spotted lady beetle. Adult lady beetles were present at the beginning of the trial, while larvae were not. Adults lady beetles were decreased by all treatments relative to the control at 7 and 10 DAT. This is not unexpected given that all materials were effective against weevils, which is a beetle, just like lady beetles. There were still some lingering effects on adult lady beetles even through 21 DAT. Larvae were not present at the beginning of the trial, but once they showed up later, we saw effects of all of our insecticides on their populations relative to the untreated. It is likely the effects of adults at least partially explained what was happening with the larvae since the adults were not in some plots reproducing.
Effect of treatments on lady beetle adults. Treatments that do not share a letter are statistically different within a sampling date.
Effect of treatments on lady beetle larvae. Treatments that do not share a letter are statistically different within a sampling date.
Minute pirate bugs (Orius, data not presented) were affected by our treatments. Adult populations were highest in the untreated and Steward treatments at 7 and 10 DAT. Generally, the isocycloseram treatments were intermediate, with Endigo ZCX and Warrior having lower populations. Their clearly was some effect of this new material on minute pirate bugs, although the effect was not as extreme as pyrethroids, which we know are broad-spectrum insecticides.
We also counted parasitoid wasps in our samples, which could be parasitoids of aphids, caterpillars, or weevils. There was a consistent trend across dates, with the lowest numbers of wasps in the Warrior treatment, the highest number in the untreated, and all other treatments having intermediate numbers. This seems fairly similar to the minute pirate bug results, although with a bit less separation among treatments (isocycloseram treatments were statistically not different from either the untreated or the Warrior plots).
Overall, it appears isocycloseram has some negative effects on natural enemies but it does a better job conserving natural enemies than pyrethroids. Meanwhile, Steward minimally affects some natural enemies but clearly negatively affects others (lady beetles) which can be important natural enemies in alfalfa.
Conclusions
The results from this trial clearly indicate that isocycloseram is a novel mode of action that could have great potential for use managing alfalfa weevils. If registered in CA in alfalfa, this material could provide another option for weevils and another mode of action to use in rotation. This is especially critical given the severely limited number of effective options currently. Furthermore, in some areas, pyrethroids are ineffective due to insecticide resistance, placing an intense burden and selection pressure on the remaining materials, which is basically Steward in most cases. All other treatments worked very well on weevils, which is not unexpected.
- Author: Kathy Keatley Garvey
She will speak on "Interdisciplinary Collaborations in Pest Management Research--My Alfalfa Weevil Stories" in a seminar hosted by agricultural entomologist Ian Grettenberger, assistant professor, UC Davis Department of Entomology and Nematology.
This the first in a series of the winter seminars to take place on Wednesdays at 4:10 p.m., beginning Jan. 5 and continuing through March 9, announced seminar coordinator and nematologist Shahid Siddique, assistant professor. Both in-person and virtual seminars will be broadcast via Zoom at https://ucdavis.zoom.us/j/
"Alfalfa weevil was first found in the Western United States in the early 1900s and continues to be a particularly problematic pest in the Western United States," Jabbour says in her abstract. "I will share current research to improve sustainability of alfalfa weevil management, much of which centers on timing –both harvest timing and pesticide spray timing. I will talk about my favorite things: biological control, interdisciplinarity, farmer perspectives, and new ideas from grad students."
Jabbour says her overall research "is to utilize ecological interactions to design sustainable agricultural systems. Specifically, I study 1) pest management in cropping systems, 2) the effect of biodiversity and habitat heterogeneity on ecosystem services, and 3) the role of farmer decision-making in agricultural management, in collaboration with social scientists. Here in Wyoming, I plan to develop research projects in these areas in relevant field crop and forage systems, in collaboration with faculty and Extension professionals here at the University and with others in the region."
Jabbour holds a bachelor of science degree (2003) from the Rochester Institute of Technology and a doctorate from Pennsylvania State University, where she focused on the biological pest control of insects. She served as a postdoctoral scholar from 2009 to 2010 at Washington State University, where "I studied the effects of pathogen diversity on host mortality of the Colorado potato beetle, gaining perspective in both biodiversity-ecosystem functioning research and the practical realities of 'big ag' potato fields." She completed a second post-doctoral position at the University of Maine, where she engaged in "balanced teaching and research responsibilities."
Jabbour's research at the University of Maine, in collaboration with social scientists and her supervisor Eric Gallandt, characterized New England organic farmer weed management philosophies, she wrote on her website. "This project was a great opportunity for me to incorporate the human dimension of pest management into my ecological research. I also collaborated with MS student Sonja Birthisel to quantify sources of variation of weed seed predation rates in a diverse Maine agricultural landscape. I particularly appreciate learning from the extensive experience of farmers, and I am passionate about supporting local food systems. I enjoy exploring the dramatic landscapes of the West, and feel as if I have just barely begun traveling around the big wondrous expanse that is my new home in Wyoming-- lots of ground to cover! In my spare time, I enjoy hiking, road trips, cooking, yoga, trying to be a runner again, and reading all sorts of things."
The remainder of the seminars in January are:
Jan. 12, 2022
Sylvia Fischer, Mosquito Study Group, Department of Ecology, Genetics and Evolution, Universidad de Buenos Aires
Virtual seminar
Title: "Recent Expansion of Aedes aegypti Distribution: Are the Populations Adapting to Colder Climate Regions?"
Host: Erin "Taylor Kelly, doctoral student in the Geoffrey Attardo lab, UC Davis Department of Entomology and Nematology
Jan. 19, 2022
Megan Meuti, assistant professor, Department of Entomology, The Ohio State University
Virtual seminar
Title: "How Do Mosquitoes Correctly Interpret Environmental Signals into Complex Seasonal Responses?"
Host: Geoffrey Attardo, assistant professor, UC Davis Department of Entomology and Nematology
Jan. 19, 2022
Megan Meuti, assistant professor, Department of Entomology, The Ohio State University
Virtual seminar
Title: "How Do Mosquitoes Correctly Interpret Environmental Signals into Complex Seasonal Responses?"
Host: Geoffrey Attardo, assistant professor, UC Davis Department of Entomology and Nematology
Jan. 26, 2022
Tobin Hammer, postdoctoral researcher, University of Texas, Austin (he will start as an assistant professor in UC Irvine's Ecology and Evolutionary Biology Department in January 2022)
In-person seminar
Title: "Diversity and Dynamism in Social Bee Microbiomes"
Host: Rachel Vannette, associate professor, UC Davis Department of Entomology and Nematology
See schedule for complete list of winter quarter seminars. For technical issues, Siddique may be reached at ssiddique@ucdavis.edu.
![The alfalfa weevil, Hypera postica. (Courtesy of Wikipedia) The alfalfa weevil, Hypera postica. (Courtesy of Wikipedia)](/blogs/blogcore/blogfiles/87957.jpg)
- Author: Kathy Keatley Garvey
Nematologist Shahid Siddique, assistant professor, UC Davis Department of Entomology and Nematology, not only excels at research, teaching and public service but he serves as the coordinator of the department's weekly seminars for the 2021-22 academic year. And he's the host for many of the speakers as well.
Siddique, who holds a doctorate in agriculture and biotechnology from the University of Natural Resources and Life Sciences, Vienna, Austria, joined the UC Davis faculty in March 2019 (see news story), after serving as a research group leader for several years at the University of Bonn, Germany.
The fall quarter seminars just ended, and the winter quarter seminars will begin Jan. 5 and continue through March 9. They take place on Wednesdays at 4:10 p.m. in 122 Briggs Hall, located off Kleiber Hall Drive. The topics range from alfalfa weevil to the yellow-fever mosquito.
"Both in-person and virtual seminars will be broadcast via Zoom at https://ucdavis.zoom.us/j/
The schedule:
Randa Jabbour, associate professor, agroecology, University of Wyoming
Virtual seminar
Title: "Interdisciplinary Collaborations in Pest Management Research--My Alfalfa Weevil Stories"
Host: Ian Grettenberger, assistant professor, UC Davis Department of Entomology and Nematology
Jan. 12, 2022
Sylvia Fischer, Mosquito Study Group, Department of Ecology, Genetics and Evolution, Universidad de Buenos Aires
Virtual seminar
Title: "Recent Expansion of Aedes aegypti Distribution: Are the Populations Adapting to Colder Climate Regions?"
Host: Erin "Taylor" Kelly, doctoral student in the Geoffrey Attardo lab, UC Davis Department of Entomology and Nematology
Jan. 19, 2022
Megan Meuti, assistant professor, Department of Entomology, The Ohio State University
Virtual seminar
Title: "How Do Mosquitoes Correctly Interpret Environmental Signals into Complex Seasonal Responses?"
Host: Geoffrey Attardo, assistant professor, UC Davis Department of Entomology and Nematology
Jan. 26, 2022
Tobin Hammer, postdoctoral researcher, University of Texas, Austin (he will start as an assistant professor in UC Irvine's Ecology and Evolutionary Biology Department in January 2022)
In-person seminar
Title: "Diversity and Dynamism in Social Bee Microbiomes"
Host: Rachel Vannette, associate professor, UC Davis Department of Entomology and Nematology
Feb. 2, 2022
Simon Niels Groen, assistant professor, Department of Nematology, UC Riverside
In-person seminar
Title: "Plant Toxins and the Evolution of Host-Parasite Interactions"
Host: Shahid Siddique, assistant professor, UC Davis Department of Entomology and Nematology
Feb. 9, 2022
Vince D'Amico, research entomologist, Communities and Landscapes of the Urban Northwest, U.S. Department of Agriculture
In-person seminar
Title: "Monitoring and Ecological Research in the Forests of the BosWash Megalopolis"
Host: Geoffrey Attardo, assistant professor, UC Davis Department of Entomology and Nematology
Feb. 16, 2022
Michelle Heck, adjunct associate professor and research molecular biologist, Boyce Thompson Institute, Ithaca, N.Y.
Virtual seminar
Title: Topic to be announced (Her program uses a combination of molecular, genetic, and proteomics approaches to understand how insects transmit plant pathogens and how pathogens manipulate host plants to ensure replication and transmission. A second area of research is the development of new pest management tools to enhance cultural control and to provide new management strategies for insect vector-borne diseases in plants)
Host: Tiffany Lowe-Power, assistant professor, UC Davis Department of Plant Pathology
Feb. 23, 2022
Adam Steinbrenner, assistant professor, Department of Biology, University of Washington
In-person seminar
Title: "Plant Immune Recognition of Insect Herbivores"
Host: Shahid Siddique, assistant professor, UC Davis Department of Entomology and Nematology
March 2, 2022
Erica Henry, postdoctoral scholar, conservation biology, North Carolina State University
In-person seminar
Title: "Insect Conservation in an Uncertain Future"
Host: Emily Meineke, assistant professor, UC Davis Department of Entomology and Nematology
March 9, 2022
Melissa Mitchum, professor, plant nematology, University of Georgia
Virtual seminar
Title: "The Tricks Phytonematodes Use to Modulate Plant Development"
Host: Shahid Siddique, assistant professor, UC Davis Department of Entomology and Nematology
For any Zoom technical issues, Siddique may be reached at ssiddique@ucdavis.edu.
![The yellow fever mosquito, Aedes aegypti, will be the topic of a UC Davis Department of Entomology and Nematology seminar on Jan. 12. (Photo courtesy of the Center for Disease Control and Prevention) The yellow fever mosquito, Aedes aegypti, will be the topic of a UC Davis Department of Entomology and Nematology seminar on Jan. 12. (Photo courtesy of the Center for Disease Control and Prevention)](/blogs/blogcore/blogfiles/87654.jpg)
![The alfalfa weevil, Hypera postica, will be discussed at the Jan. 5 seminar hosted by the UC Davis Department of Entomology and Nematology. (Wikipedia photo by AfroBrazilian) The alfalfa weevil, Hypera postica, will be discussed at the Jan. 5 seminar hosted by the UC Davis Department of Entomology and Nematology. (Wikipedia photo by AfroBrazilian)](/blogs/blogcore/blogfiles/87655.jpg)
- Author: Kathy Keatley Garvey
Both in-person and virtual seminars will be broadcast via Zoom at https://ucdavis.zoom.us/j/
The schedule:
Jan. 5, 2022
Randa Jabbour, associate professor, agroecology, University of Wyoming
Virtual seminar
Title: "Interdisciplinary Collaborations in Pest Management Research--My Alfalfa Weevil Stories"
Host: Ian Grettenberger, assistant professor, UC Davis Department of Entomology and Nematology
Jan. 12, 2022
Sylvia Fischer, Mosquito Study Group, Department of Ecology, Genetics and Evolution, Universidad de Buenos Aires
Virtual seminar
Title: "Recent Expansion of Aedes aegypti Distribution: Are the Populations Adapting to Colder Climate Regions?"
Host: Erin "Taylor Kelly, doctoral student in the Geoffrey Attardo lab, UC Davis Department of Entomology and Nematology
Jan. 19, 2022
Megan Meuti, assistant professor, Department of Entomology, The Ohio State University
Virtual seminar
Title: "How Do Mosquitoes Correctly Interpret Environmental Signals into Complex Seasonal Responses?"
Host: Geoffrey Attardo, assistant professor, UC Davis Department of Entomology and Nematology
Tobin Hammer, postdoctoral researcher, University of Texas, Austin (he will start as an assistant professor in UC Irvine's Ecology and Evolutionary Biology Department in January 2022)
In-person seminar
Title: "Diversity and Dynamism in Social Bee Microbiomes"
Host: Rachel Vannette, associate professor, UC Davis Department of Entomology and Nematology
Feb. 2, 2022
Simon Niels Groen, assistant professor, Department of Nematology, UC Riverside
In-person seminar
Title: "Plant Toxins and the Evolution of Host-Parasite Interactions"
Host: Shahid Siddique, assistant professor, UC Davis Department of Entomology and Nematology
Feb. 9, 2022
Vince D'Amico, research entomologist, Communities and Landscapes of the Urban Northwest, U.S. Department of Agriculture
In-person seminar
Title: "Monitoring and Ecological Research in the Forests of the BosWash Megalopolis"
Host: Geoffrey Attardo, assistant professor, UC Davis Department of Entomology and Nematology
Feb. 16, 2022
Michelle Heck, adjunct associate professor and research molecular biologist, Boyce Thompson Institute, Ithaca, N.Y.
Virtual seminar
Title: Topic to be announced (Her program uses a combination of molecular, genetic, and proteomics approaches to understand how insects transmit plant pathogens and how pathogens manipulate host plants to ensure replication and transmission. A second area of research is the development of new pest management tools to enhance cultural control and to provide new management strategies for insect vector-borne diseases in plants)
Host: Tiffany Lowe-Power, assistant professor, UC Davis Department of Plant Pathology
Feb. 23, 2022
Adam Steinbrenner, assistant professor, Department of Biology, University of Washington
In-person seminar
Title: "Plant Immune Recognition of Insect Herbivores"
Host: Shahid Siddique, assistant professor, UC Davis Department of Entomology and Nematology
March 2, 2022
Erica Henry, postdoctoral scholar, conservation biology, North Carolina State University
In-person seminar
Title: "Insect Conservation in an Uncertain Future"
Host: Emily Meineke, assistant professor, UC Davis Department of Entomology and Nematology
March 9, 2022
Melissa Mitchum, professor, plant nematology, University of Georgia
Virtual seminar
Title: "The Tricks Phytonematodes Use to Modulate Plant Development"
Host: Shahid Siddique, assistant professor, UC Davis Department of Entomology and Nematology
For any Zoom technical issues, Siddique may be reached at ssiddique@ucdavis.edu.
![This is the alfalfa weevil, Hypera postica. Randa Jabbour of the University of Wyoming will discuss her research on the pest at her UC Davis seminar on Jan. 5. (Image courtesy of Wikipedia, AfroBrazilian) This is the alfalfa weevil, Hypera postica. Randa Jabbour of the University of Wyoming will discuss her research on the pest at her UC Davis seminar on Jan. 5. (Image courtesy of Wikipedia, AfroBrazilian)](/blogs/blogcore/blogfiles/87647.jpg)
![This is the yellow fever mosquito, Aedes aegypti. Sylvia Fischer of the Universidad de Buenos Aires will present a UC Davis virtual seminar on This is the yellow fever mosquito, Aedes aegypti. Sylvia Fischer of the Universidad de Buenos Aires will present a UC Davis virtual seminar on](/blogs/blogcore/blogfiles/87648.jpg)
![The schedule of seminars for the winter quarter, UC Davis Department of Entomology and Nematology The schedule of seminars for the winter quarter, UC Davis Department of Entomology and Nematology](/blogs/blogcore/blogfiles/87938.png)