- Author: Kathy Keatley Garvey
Should we now worry about those Asian giant hornets becoming residents of our Golden State?
No, says entomologist Lynn Kimsey, director of the Bohart Museum of Entomology and professor of entomology, UC Davis Department of Entomology and Nematology.
Kimsey, a global authority on wasps, bees and other insects, is a two-term past president of the International Society of Hymenopterists. She recently co-authored “The Diversity of Hornets in the Genus Vespa (Hymenoptera: Vespidae; Vespinae); Their Importance and Interceptions in the United States” in the journal Insect Systematics and Diversity with two other entomologists: lead author Allan Smith-Pardo, U.S. Department of Agriculture Animal and Plant Health Inspection Service (APHIS); and James Carpenter of the American Museum of Natural History's Division of Invertebrate Zoology.
The latest news: the Washington State Department of Agriculture (WSDA) announced Oct. 24 that a nest was discovered and destroyed in a tree cavity near Blaine, Wash. This marked Washington's first known nest of Vespa mandarinia. North America's first detected colony of the giant hornets was destroyed in September 2019 on Vancouver Island, British Columbia. A single V. mandarinia was found dead in Blaine, Wash., in December 2019.
But to worry. The hornet won't like California's hot, dry summers and lack of rainfall.
As Kimsey told reporter Kellie Hwang of the San Francisco Chronicle: "It is exceedingly unlikely that these hornets can establish in California. If you look at where they're found in their native range in southern Asia, this region has summer rain. I think California is too dry, except perhaps along the far northern coast.”
Washington State University (WSU) entomologists and their colleagues agree. They recently "examined more than 200 records from the hornet's native range in Japan, South Korea, and Taiwan, then used a set of ecological models incorporating climate data to predict likely global habitat across six continents," according to a WSU news release.
They found that "Asian giant hornets are most likely to thrive in places with warm summers, mild winters, and high rainfall. Extreme heat is lethal, so their most suitable habitats are in regions with a maximum temperature of 102 degrees Fahrenheit. Based on those factors, suitable habitat for the giant hornet exists along much of the U.S. west and east coasts, adjacent parts of Canada, much of Europe, northwestern and southeastern South America, central Africa, eastern Australia, and most parts of New Zealand."
"Much of the interior of the U.S. is inhospitable to the hornet due to extremes of heat, cold, and low rainfall," the news release related. "This includes the eastern parts of Washington state and British Columbia, as well as California's Central Valley, all of which have major fruit and nut crops that rely on honey bee pollination."
Scientists dislike the sensationalized name "murder hornets" (so named because insects can quickly destroy a honey bee colony). The insects defend their colony when it is threatened, but generally will not attack people or pets, according to WSDA. The fear is there, though. "Their stinger is longer than that of a honeybee and their venom is more toxic," WSDA says. "They can also sting repeatedly."
But "murder hornets?"
Maybe we should just call them "giant hornets," you think?
- Author: Kathy Keatley Garvey
The article, “Genome-Enabled Insights into the Biology of Thrips as Crop Pests,” is published in the journal BMC Biology. It is the work of 57 scientists on five continents.
“This project represents over eight years of work by at least 17 laboratories across the globe,” said Professor Ullman, a former chair of the entomology department and a fellow of the Entomological Society of America and the American Association for the Advancement of Science. Her laboratory worked closely with project leader and first author Dorith Rotenberg of North Carolina State University. Project scientist Sulley Ben-Mahmoud of the Ullman lab is the paper's third author.
The western flower thrips, Frankliniella occidentalis, causes billions of dollars a year in damage worldwide. Native to Western North America and about the size of a pinhead, the insect feeds on a wide array of food, fiber, and ornamental crops and transmits plant viruses that cause significant economic damage.
“The western flower thrips and the viruses it transmits, including tomato spotted wilt virus, is important to California agriculture, causing serious problems for tomato growers, pepper growers and growers of leafy greens,” Ullman said. The tomato spotted wilt virus infects more than 1000 plant species, ranging from tomatoes, tobacco and peanuts to pansies and chrysanthemums.
“This system has been a central element of my research program for over 30 years," Ullman said, "and I am extremely excited to see this important resource made available as a tool to help us understand and control these important pests.”
In their abstract, the authors wrote that the publication should lead to “understanding the underlying genetic mechanisms of the processes governing thrips pest and vector biology, feeding behaviors, ecology, and insecticide resistance.”
This is the first genome sequence and analysis for a member of the Thysanoptera, an order that contains more than 7,000 species of small insects with fringed wings.
(See more information on the project on the UC Davis Department of Entomology and Nematology website)
- Author: Kathy Keatley Garvey
Don't miss the UC Davis Bohart Museum of Entomology virtual open house on alfalfa and rice from 11 a.m. to noon on Thursday, Oct. 22.
Cooperative Extension agricultural specialist Ian Grettenberger, assistant professor, UC Davis Department of Entomology and Nematology, and his second-year graduate student, Madison "Madi" Hendrick, will discuss the crops, the pests, and the natural enemies or beneficials.
The good: Think the lady beetle, aka ladybug, that can devour some 50 aphids a day.
The bad: Think the larvae of the alfalfa butterfly, a major pest of alfalfa. Other pests of alfalfa include the Western yellowstriped armyworm, beet armyworm, and alfalfa weevil. Among the pests of rice: armyworms, aster leafhoppers, crayfish, rice leafminers, rice seed midges, rice water weevils and tadpole shrimp.
The bugly: Think all the arthropods--pests and natural enemies.
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 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.
As Tabatha Yang, education and outreach coordinator of the Bohart Museum, says: "This is all about the arthropods, both the pests and beneficials that they study in the rice and alfalfa fields." Most of the focus is on insects, but tadpole shrimp in rice fields also will be discussed." A virtual family craft activity on rice 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."
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."
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. (Gift items can now be shipped during the closure.)
More information on the Bohart Museum's virtual presentation is available on its website or by contacting Yang at tabyang@ucdavis.edu.
- Author: Kathy Keatley Garvey
Mosquito researcher Maria Onyango, a postdoctoral associate at the New York State Department of Health, Albany, N.Y., will speak on "The Impact of Zika Virus Infection on the Metabolites and Microbiome of Aedes albopictus" from 4:10 to 5 p.m. The Zoom seminar is open to all interested persons; click here for the form to register and obtain the Zoom link.
Aedes albopictus, known as the Asian tiger mosquito, is a close relative of Aedes aegypti, the yellow fever mosquito. Both invasive species are moving through California. (See California report of the two species, and the Center for Disease Control and Prevention's estimate potential range of the two species in the United States.)
Medical entomologist-geneticist Geoffrey Attardo of the UC Davis Department of Entomology and Nematology, who collaborates with Onyango, will host the seminar.
"Dr. Maria Onyango works on the biology underlying interactions between arboviruses (Zika virus), vector mosquitoes and the associated microbiome," Attardo said.
Aedes aegypti Detected in Yolo County
The Sacramento-Yolo Mosquito and Vector Control District recently announced the detection of Aedes aegypti in Yolo County: an adult female found Sept. 15 in a trap near East and Main streets, Winters, and an adult female found in in a trap at Pioneer Park near El Macero, Davis, on Sept. 30.
Aedes aegypti, a day-biting mosquito originating from the forests of Uganda, can transmit the Zika virus, yellow fever, dengue, and chikungunya. However, California has no documented cases of this species transmitting the Zika virus, dengue or chikungunya.
Attardo related that the first detection of Aedes aegypti in California occurred in 2013 and was described in these papers:
- Metzger, M.E.; Hardstone Yoshimizu, M.; Padgett, K.A.; Hu, R.; Kramer, V.L. Detection and Establishment of Aedes aegypti and Aedes albopictus (Diptera: Culicidae) Mosquitoes in California, 2011-2015. J. Med. Entomol. 2017, 54, 533–543, doi:10.1093/jme/tjw237.
- Gloria-Soria, A.; Brown, J.E.; Kramer, V.; Hardstone Yoshimizu, M.; Powell, J.R. Origin of the dengue fever mosquito, Aedes aegypti, in California. PLoS Negl. Trop. Dis. 2014, 8, e3029, doi:10.1371/journal.pntd.0003029.
"Since then it has been determined that there have likely been at least two separate introductions of Aedes into California--possibly three but that requires additional study," Attardo says. "The result of this is that there are two genetically distinct populations of Aedes in California. One is based in Southern California in the Greater Los Angeles area as well as areas to the East, like Riverside and Coachella valleys. The second population is distributed throughout the Central Valley. These two populations are genetically distinct and we have developed a genetic assay to differentiate the two populations. We have been working with local abatement agencies (Winters, Sacramento/Yolo and Shasta counties) to test their collected mosquitoes to determine which population they resemble at the genetic level. Each year has shown Aedes aegypti spreading farther into parts of California where it has never been seen before."
- Pless, E.; Gloria-Soria, A.; Evans, B.R.; Kramer, V.; Bolling, B.G.; Tabachnick, W.J.; Powell, J.R. Multiple introductions of the dengue vector, Aedes aegypti, into California. PLoS Negl. Trop. Dis. 2017, 11, e0005718, doi:10.1371/journal.pntd.0005718.
- Lee, Y.; Schmidt, H.; Collier, T.C.; Conner, W.R.; Hanemaaijer, M.J.; Slatkin, M.; Marshall, J.M.; Chiu, J.C.; Smartt, C.T.; Lanzaro, G.C.; et al. Genome-wide divergence among invasive populations of Aedes aegypti in California. BMC Genomics 2019, 20, 204, doi:10.1186/s12864-019-5586-4.
"We recently ran our genetic test on mosquitoes that we collected from two different sites in Citrus Heights (divided by Route 80) and actually found that the two groups appear to represent both the Greater Los Angeles and the Central Valley populations, with each group specific to one side or the other of Route 80," Attardo said. "This is unpublished data and we are continuing to process additional samples of collected Aedes to reinforce these findings and understand the dynamics of how these mosquitoes are spreading."
The data suggests "that both populations are moving throughout California and are possibly being facilitated by human activities," Attardo said. "Aedes aegypti which was originally a mosquito that developed in tree holes has evolved to be a very human centric mosquito that has learned to thrive in man-made breeding sites. This may be the key to their success and their ability to move so quickly throughout the state."
Attardo emphasized that "these mosquitoes do not naturally carry these viruses and must acquire them by blood feeding on an infected person, successfully developing an infection and then biting another person. So far there have been no outbreaks of these diseases, but now that Aedes aegypti is here, the potential for an outbreak of dengue, Zika, chikungunya or yellow fever is a possibility. Infected people coming from countries where these viruses are endemic could serve to seed the viruses into Californian populations of Aedes which would obviously be a bad thing. The ongoing environmental changes resulting from climate change will likely allow these mosquitoes and others to move into previously uninhabitable areas and it is going to significantly change how we assess risk and management of mosquito-borne disease risks in the United States and around the world. California is just one example of this issue."
Aedes albopictus in California
Along with seven other scientists, Attardo and Onyango co-authored a research article in the Oct. 2nd edition of Frontiers in Microbiology on "Zika Virus Infection Results in Biochemical Changes Associated With RNA Editing, Inflammatory and Antiviral Responses in Aedes albopictus."
Aedes albopictus, also a day-biting mosquito, can transmit Zika and other infectious diseases. "The Zika virus infected more than 1 million people during an epidemic that began in 2015 in Brazil," according to this report, Invasive Mosquito Species Plunge Deeper Into California. The virus also can spread during sex.
Onyango holds two degrees from the University of Nairobi, Kenya: a bachelor of science degree in biochemistry and zoology and a master's degree in applied parasitology. She received her doctorate in veterinary entomology from Deakin University and Australian Animal Health Laboratory, Commonwealth Scientific and Industrial Research Organisation (CSIRO), and then completed postdoctoral training at the Yale School of Public Health, Department of Epidemiology of Microbial Diseases.
Cooperative Extension specialist and assistant professor Ian Grettenberger coordinates the fall seminars. For any technical issues regarding the seminar, contact Grettenberger at imgrettenberger@ucdavis.edu
- Author: Kathy Keatley Garvey
The Bohart Museum of Entomology at the University of California, Davis, is hosting a virtual open house dealing with alfalfa and rice.
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.
Yes, this applies to you. If you're a scientist or would-be scientist, you'll want to know more about these agricultural crops and the issues. If you're a consumer and like rice and ice cream (dairy cows eat alfalfa and milk comes from ice cream, you have a stake in this.
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.
"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. (Gift items can now be shipped during the closure.)
More information on the Bohart Museum's virtual presentation is available on its website or by contacting Yang at tabyang@ucdavis.edu.
Resources:
- 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
