- Author: Kathy Keatley Garvey
The Deep Look crew filmed the footage of the varroa mites with the assistance of Niño and Joseph Tauzer, manager of the Harry H. Laidlaw Jr. Honey Bee Research Facility, Bee Biology Road. Other segments of the production were filmed elsewhere.
The video was publicly released Oct. 24.
"They really did a great job, just like with the one on bee bread also done in my lab a few years back (2019)," said Niño, who also is the founder and director of the California Master Beekeeper Program. (See "Honey Bees Make Honey...and Bread?")
Varroa mites (Varroa destructor), natives of Asia, are external parasitic mites that feed on and weaken honey bees. They can spread such viruses as the deformed wing virus.
Beekeepers typically describe varroa mites as "Public Enemy No. 1" or as "A Beekeeper's Worst Enemy." In the Deep Look video, host Laura Klivans comments: "Every year, up to half the managed honeybee hives in the United States die from hazards like pesticide exposure, lack of flowers to forage on year-round, and varroa mites...varroa mites are great at sneaking into hives, hiding, and reproducing like mad."
Varroa mites reproduce only in a bee colony. The mites are small--measuring about 1–1.8 mm long and 1.5–2 mm wide--but they are huge to a bee. "It's as if you were carrying around a tick the size of a dinner plate," Klivans says.
Scientists first detected varroa mites in the United States in the 1980s. "They evolved on eastern honeybees, in Asia," Klivans notes. "That's why the western honeybees in the Americas and Europe aren't yet good at defending against them."
Research is underway to breed bees that will better target the mites. "The U.S. Department of Agriculture and private companies are breeding bees that can sniff out varroa mites," according to Deep Look. "When the bees find some, they uncap the cells and interrupt reproduction."
The video also focuses on "the sugar shake," a procedure used to monitor and estimate the number of varroa mites in a bee colony. It involves adding a half of a cup of bees (about 300) from the brood comb to a jar with a mesh lid, dropping in two tablespoons of confectioners' sugar, shaking the jar for 30 seconds to dislodge the mites, and emptying the contents on a tray. The beekeepers then count the number of varroa mites, estimate the severity of infestation, and decide what needs to be done.
Deep Look humorously describes the sugar-coated mites as "frosted varroa mites."
"The U.S. Department of Agriculture and private companies are breeding bees that can sniff out varroa mites," Klivans tells viewers. "When the bees find some, they uncap the cells and interrupt reproduction." Through queen bee insemination, scientists at Purdue and Central State universities are breeding honeybees known as “mite-biters." (See news story)
In addition to Niño and Tauzer, researchers consulted included Adam Finkelstein, VP Queen Bees; Krispn Given, Purdue Universities; Cameron Jack, University of Florida; Jeff Harris, Mississippi State University; Hongmei Li-Byarlay, Central State University; Samuel Ramsey, University of Colorado, Boulder; and Frank Rinkevich, USDA.
Credits include Deep Look producer/writer Gabriela Quirós; cinematographer Josh Cassidy; narrator/writer Laura Klivans; original music Seth Samuel; and editors/motion graphics Gabriela Quirós and Kia Simon.
In 2007, Deep Look filmed bee breeder-geneticist Susan Cobey (now of Washington State University) inseminating bee queens in the Laidlaw lab. At the time, Cobey managed the Laidlaw facility. Also in the video, the late Eric Mussen (1944-2022), Extension apiculturist and member of the UC Davis Department of Entomology and Nematology faculty, discusses colony collapse disorder.
- Author: Kathy Keatley Garvey
Attardo will discuss “The Mating Biology of Tsetse Flies--Insights into the Morphological, Biochemical, and Molecular Responses to Mating Stimuli in a Viviparous Disease Vector.”
"Research into the reproductive behavior of tsetse flies offers key insights into controlling diseases like African sleeping sickness," he writes in his abstract. "Unique among insects, these flies give birth to live offspring. During mating, males transfer a mix of sperm and other vital substances to the females. This study employs state-of-the-art techniques, including 3D scanning and genetic analysis, to monitor changes in the female fly's reproductive system over a 72-hour period post-mating. Findings indicate that mating sets off a chain of intricate changes in the female, affecting everything from biochemistry to gene activity. These changes prepare her for pregnancy and childbirth. The study opens up new avenues for understanding tsetse fly biology and offers potential strategies for disease control."
The seminar also will be on Zoom. The link:
https://ucdavis.zoom.us/j/95882 849672
The Attardo lab monitors the dynamics of vector insects at the levels of physiology, population genetics and environmental interactions.
Attardo is a global expert on vectorborne diseases, including his groundbreaking work on tsetse flies. He researches the invasive yellow mosquito, Aedes aegypti, which can carry such diseases as dengue, chikungunya, Zika and yellow fever. His work involves predicting insecticide resistance and tracking movements of genetically independent populations of aegypti throughout the state.
Attardo, who holds a doctorate in genetics from Michigan State University, where he researched the molecular biology of mosquito reproduction, joined the UC Davis Department of Entomology and Nematology in 2017 from the Yale School of Public Health's Department of Epidemiology of Microbial Diseases.
He received the 2022 Medical, Urban, and Veterinary Entomology Award from the Pacific Branch, Entomological Society of America, which encompasses 11 Western states, plus parts of Canada and Mexico, and U.S. territories.
For any technical issues regarding Zoom, contact seminar coordinator Brian Johnson at brnjohnson@ucdavis.edu.
Resources:
- Tsetse Fly Research (article featuring Geoffrey Attardo, Feb. 3, 2021, UC Davis Department of Entomology and Nematology
- A Tsetse Fly Births One Enormous Milk-Fed Baby, Deep Look, featurng the work of Geoffrey Attardo
- Author: Kathy Keatley Garvey
Agricultural entomologist and Cooperative Extension specialist Ian Grettenberger of the UC Davis Department of Entomology and Nematology and his colleagues propose alternative management.
Grettenberger's poster, “Past Pyrethroids: Alternative Management Approaches for Tadpole Shrimp in Rice,” presented at Entomological Society of America meeting (Oct. 31-Nov. 3) in Denver, offers non-pesticide alternatives, including the use of mosquitofish.
Collaborative research with UCCE Butte County director and Rice Farming Systems Advisor Luis Espino and UC Davis staff research associate Kevin Goding, indicates that mosquitofish proved able to suppress shrimp populations.
“Tadpole shrimp (Triops longicaudatus) are an early-season pest in California rice,” Grettenberger explained in his abstract. “Soon after flooding, eggs hatch and growing shrimp are soon large enough to damage germinating rice seedlings. Currently, pyrethroid insecticides are heavily relied upon for management, as they are in many cropping systems, because of their efficacy and low cost. However, contamination of surface waters is a concern, as is insecticide resistance.”
"We evaluated alternative management strategies that could be used to manage tadpole shrimp,” he wrote. “We tested a number of materials using small metal ring plots and natural shrimp populations. This included several timings of applications to mimic an early, more proactive application along with a later, rescue application, as well as reduced rates of a number of insecticides.”
Deep Look Video. Tadpole shrimp recently made the national news in two ways, Grettenberger said. First, they made news with the sudden appearance of tadpole shrimp following monsoon rains this summer in an ancient ceremonial ball court at the Wupatki National Monument in northern Arizona (https://www.livescience.com/dinosaur-shrimp-emerge-arizona). In October, KQED's Deep Look released a new video, “Tadpole Shrimp Are Coming For Your Rice," the work of lead producer and cinematographer Josh Cassidy and other members of the Deep Look crew. (See https://youtu.be/T2xnXaX7r3g.) Grettenberger assisted with the project, providing tadpole shrimp and taking some of the video clips used in the five-minute video.
“Much of his shooting was in my garage,” the UC Davis entomologist said, “so I get to see just how much effort and care goes into producing these videos. They end up pretty short, but that doesn't mean it is simple to get all the pieces together.”
“This tadpole shrimp is coming for your rice,” the narrator said. “Hungry hordes of them find their way into the ice fields of California's Central Valley and go to town munching on the young seedlings. But where did they come from, with the ocean so far away? A couple of weeks ago, this was just a dry dusty field. Turns out they were here all along.”
Deep Look referred to them as “time travelers,” as the eggs of shrimp tadpoles can be viable for decades and hatch when the rice growers flood their fields. "At the very least, they have survived as eggs since last season," Grettenberger noted.
The pests are neither tadpoles or shrimp but are fresh-water crustaceans descended from the ocean. “They look like tiny horseshoe crabs,” Grettenberger told Deep Look. “It's obvious when rice fields have lots of tadpole shrimp in them, because they stir up the mud making the water look a bit like chocolate milk. There will also be shrimp zooming around, many upside down at the surface, popping up for a few seconds before disappearing back into the murkiness."
Adult tadpole shrimp cannot survive when the soil dries out. But Grettenberger said their eggs have a rugged outer layer called a “chorion” that protects the eggs from desiccation.
“They've been living this way for hundreds of millions of years-- since before the dinosaurs-- waiting out droughts, changing climates, even global catastrophes,” KQED relates in the video. “In a world where the future is unpredictable, tadpole shrimp are the ultimate survivors.”
Grettenberger, who joined the UC Davis Department of Entomology faculty in January, 2019, focuses his research on field and vegetable crops; integrated pest management; applied insect ecology; and biological control of pests.
Additional Information:
- Resource on tadpole shrimp, UC Statewide Integrated Pest Management Program (co-authors, the late Larry Godfrey, UC Davis Department of Entomology and Nematology; Luis Espino, UC Cooperative Extension; and Sharon Lawler, UC Davis Department of Entomology and Nematology
- "Effect of Rice Winter Cultural Management Practices on the Size of the Hatching Population of Triops longicaudatus (Notostraca:Triopsidae) in California Rice Fields" (Co-authors Larry Godfrey,
