Ah, Saturday, April 17. It's the 107th Annual UC Davis Picnic Day! What's a picnic without bugs?
This year's event, all virtual, is themed "Discovering Silver Linings," and you can do just that by watching the pre-recorded videos and by participating in the Zoom sessions. Check out the Picnic Day schedule of events which include entomological exhibits and talks from the UC Davis Department of Entomology and Nematology, Bohart Museum of Entomology and the UC Davis Graduate Student Association.
New additions to the line-up (featured on the Bohart Museum of Entomology website), involve what you could call "The good, the bad and the bugly." Blue orchard bees, tsetse flies and mosquitoes are spotlighted in UC Davis research-based videos created by KQED's Deep Look series and presented by PBS Digital Studios. Each runs about four minutes.
Here are the KQED productions:
- Watch this Bee Build Her Bee-Jeweled Nest, featuring blue orchard bees, the project of UC Davis doctoral student Clara Stuligross.
- A Tsetse Fly Births One Enormous Milk-Fed Baby, showcasing the work of medical entomologist Geoffrey Attardo, assistant professor, UC Davis Department of Entomology and Nematology.
- This Dangerous Mosquito Lays Her Armored Eggs--in Your House, involving the Aedes aegypti mosquitoes that the Attardo lab studies.
Clara Stuligross, Doctoral Student
They exposed the bees to the neonicotinoid insecticide imidacloprid, widely used in agriculture, and found that the combined threats—imidacloprid exposure and the loss of flowering plants—reduced the bee's reproduction by 57 percent, resulting in fewer female offspring.
Other scientists have conducted similar research on honey bees, but this is the first comparable research on wild bees in field or semi-field conditions. The blue orchard bee, nicknamed BOB, is a dark metallic mason bee, smaller than a honey bee. It is prized for pollinating almond, apple, plum, pear, and peach trees. California almond growers often set up bee boxes or "bee condos" for blue orchard bees to aid in honey bee pollination. In the wild, the bees nest in reeds or natural holes.
Update? "We are currently working on a follow-up study to investigate potential carryover effects of past insecticide exposure on the same bee population, as well as how repeated pesticide exposure over multiple years impacts bee population growth," Stuligross said today.
Geoffrey Attardo, Medical Entomologist-Geneticist
What many people do not know: "Female tsetse flies carry their young in an adapted uterus for the entirety of their immature development and provide their complete nutritional requirements via the synthesis and secretion of a milk like substance," Attardo says.
Attardo led landmark research published Sept. 2, 2019 in the journal Genome Biology that provides new insight into the genomics of the tsetse fly. The researchers compared and analyzed the genomes of six species of tsetse flies. Their research could lead to better insights into disease prevention and control.
The Deep Look episode on mosquitoes, "This Dangerous Mosquito Lays Her Armored Eggs-- in Your House," deals with the ability of Aedes aegypti eggs to survive out of water. Wrote the producers: "The Aedes aegypti mosquito, which can transmit dengue fever and Zika, makes a meal of us around our homes. And her eggs are hardy. They can dry out, but remain alive for months, waiting for a little water so they can hatch into squiggly larvae."
UC Davis medical entomologist-geneticist Geoffrey Attardo, a global authority on tsetse flies, serves as the principal investigator of a research project at the Lawrence Berkeley National Laboratory (Berkeley Lab) that involves scanning the entire reproductive cycle of the fly.
Attardo and other members of the research team are exploring the intact organs and tissues of tsetse flies using a powerful 3D X-ray imaging technique. The study, “Unraveling Intersexual Interactions in Tsetse”), is funded by the National Institute of Allergy and Infectious Diseases (NAIAD) of the National Institutes of Health.
“We started this project in 2019 and the work is ongoing,” said Attardo, an assistant professor in the UC Davis Department of Entomology and Nematology and chair of the Designated Emphasis in the Biology of Vector Borne Diseases. “We actually have scans of flies through the entire reproductive cycle, however, the segmentation is ongoing. We are working on developing ways to train artificial intelligence based software to assist us with the tissue segmentations.”
The tsetse fly transmits the parasite that causes the deadly human and animal trypanosomiasis, better known as African sleeping sickness, says Attardo, who is featured in a recently posted article, "A Detailed Look Inside Tsetse Flies," on the Berkeley Lab website. (See YouTube)
“This specialized reproductive biology has required dramatic modifications to the morphology of the reproductive organs in these and related flies,” according to the Berkeley Lab News Center. “Here, we use phase contrast micro-Computed Tomography (Micro-CT) to visualize these adaptations in three dimensions for the first time. These adaptations include cuticular modifications allowing increased abdominal volume, expanded abdominal and uterine musculature, reduced egg development capacity, structural features of the male seminal secretions and detailed visualization of the gland responsible for synthesis and secretion of “milk” to feed intrauterine larvae. The ability to examine these tissues within the context of the rest of the organ systems in the fly provides new functional insights into how these changes have facilitated the evolution of the mating and reproductive biology of these flies.”
“The imaging technique provided new insights into how the flies' specialized biology governs mating and reproductive processes, including female flies' unique lactation and their delivery of a single fully developed larvae per birthing cycle – whereas most other insect species lay eggs,” according to the article. “The ALS (National Laboratory Advanced Light Source) produces X-rays and other forms of light for a broad range of simultaneous scientific experiments.”
The parasite invades the central nervous system and disrupts the sleep cycle, he says. “If not treated, the disease can result in progressive mental deterioration, coma, systemic organ failure and death.” An estimated 65 million people in 36 countries in sub-Saharan Africa are at risk for the deadly disease, according to the World Health Organization.
Attardo led a study, published in September 2020 in the journal Insects, detailing the ALS imaging work. The article, “Interpreting Morphological Adaptations Associated with Viviparity in the Tsetse Fly Glossina morsitans (Westwood) by Three-Dimensional Analysis,” received widespread attention. ALS experiments allow the researchers to create a detailed 3D visualizatiaon of the reproductive tissues without dissection and staining processes that introduce damage to the delicate samples.
“We want to understand what changes are happening during this process, how the process is being mediated, and if it can be manipulated to artificially repress females in the wild from mating,” Attardo told the Berkeley Lab News Center.
The Berkeley Lab is a multiprogram science lab in the national laboratory system supported by the U.S. Department of Energy through its Office of Science.
In his UC Davis lab, Attardo researches one of 35 tsetse fly species, Glossina morsitans morsitans, which prefers feeding on cattle to humans. Its strong mouthparts can easily puncture the tough cattle hide. In his lab, he feeds them warm cow blood.
As Attardo says on his website: "Arthropod vectored diseases cause more than 1 billion cases of illness and over 1 million deaths in humans each year. My work centers on understanding the reproductive biology of insect vectors of human disease. The goal of this work is to develop a detailed understanding of the molecular biology and physiology of these insects and to exploit this information to control these insects and the diseases they transmit. I use molecular biology and biochemical techniques in my research to address these questions. I also incorporate new technologies such as high throughput DNA sequencing and metabolomics which expand beyond the capabilities of traditional molecular techniques to understand the biology of these organisms at a systems level."
The UC Davis scientist hopes "to use the knowledge gained from these studies to improve current vector control strategies and to develop new strategies that disrupt the reproduction of these disease vectors."
Attardo holds a doctorate in genetics from Michigan State University, where he researched the molecular biology of mosquito reproduction in the lab of Alexander. Prior to joining the UC Davis faculty in 2017, Attardo worked for 13 years in the Department of Epidemiology of Microbial Diseases at the Yale School of Public Health, first as a postdoctoral associate and then as a research scientist studying the reproductive biology of tsetse flies.
In less than 48 hours, nearly 500,000 people have seen them—but not in his restricted-access lab.
His research subjects are blood-sucking tsetse flies, and PBS featured them in its Deep Look video, “A Tsetse Fly Births One Enormous Milk-Fed Baby,” released Jan. 28, and its accompanying news story.
Infected tsetse flies transmit the parasite that causes human and animal trypanosomiasis, better known as sleeping sickness. “The parasite invades the central nervous system and disrupts the sleep cycle,” says Attardo, a global authority on tsetse flies and an assistant professor in the UC Davis Department of Entomology and Nematology. “If not treated, the disease can result in progressive mental deterioration, coma, systemic organ failure and death.”
“PBS sent out a film crew and we spent about two days filming,” he said. The video also includes footage from Africa that PBS purchased, and video of a tsetse trap that Attardo filmed in the Nguruman Escarpment, Kenya, on the border of Tanzania.
Attardo researches one of 35 tsetse fly species, Glossina morsitans morsitans, which prefers feeding on cattle to humans. Its strong mouthparts can easily puncture the tough cattle hide. In his lab, he feeds them warm cow blood.
Tsetse flies, which resemble house flies, are distinguished from other Diptera by unique adaptations, including lactation and the birthing of live young, Attardo says. Just like mammals, tsetse flies, deliver babies and feed them milk. A female produces more than her body weight in milk.
“We mammals like to think we're pretty special, right?” the video begins. “We don't lay eggs. We feed our babies milk. Well, this very pregnant fly is about to prove us wrong. Yep, this tsetse fly is in labor. And that emerging bundle of joy is her larva. While other insects can lay hundreds of eggs, she grows one baby at a time inside her, just like us. Congratulations!”
The accompanying news story, by Gabriela Quirós, explains that Attardo is “trying to understand in detail the unusual way in which these flies reproduce in order to find new ways to combat the disease, which has a crippling effect on a huge swath of Africa.”
The video shows tsetse flies feeding on cattle, at which point the script reader explains that
“Geoff Attardo…hopes to help. He's trying to stop tsetse flies from making babies in the first place. A female only mates once in her life, enough to make the 10 or so babies she'll have. The male makes sure she doesn't mate again by delivering a substance that makes her lose interest in sex. Scientists are trying to figure out what it is. If they could bottle it and spray it, female tsetse flies may never get busy at all. No more tsetse offspring to worry about.”
Attardo says that tsetse flies deliver only one offspring at a time, as compared to insects that lay hundreds or thousands of eggs at one time. Spraying insects and setting traps can reduce the number who develop the disease, but the insects may become resistant to the chemicals.
Once a female mates, storing the sperm she'll birth in a lifetime, the male delivers “a substance that makes her lose interest in sex,” Quirós wrote. It is that substance or what Attarado calls a “reproductive dead end,” that Attardo wants to replicate, to bottle and spray on the tsetse flies..
“The females definitely are making the decisions,” Attardo told Quirós. “She'll sort of tuck her abdomen underneath her body to prevent him from gaining access, and buzz her wings and knock him off.”
The news story also touched on a bacterium, Wigglesworthia glossinidia, found inside the females that apparently has a role in milk production. “When they kill the bacteria with antibiotics, female flies are no longer able to grow a larva, “Queros wrote. “Young larvae stop growing inside their mothers and are aborted. The results of an experiment by Attardo, which he hasn't published yet, suggest that this happens because flies without the bacteria have trouble making milk.”
Last fall, Attardo published landmark research that provides new insight into the genomics of the blood-sucking tsetse fly. The paper, published Sept. 2 in the journal Genome Biology, compares and analyzes the genomes of six species of tsetse flies and the research could lead to better insights into disease prevention and control.
“It was a behemoth project, spanning six to seven years,” said Attardo. “This project represents the combined efforts of a consortium of 56 researchers throughout the United States, Europe, Africa and China.”
Attardo joined the UC Davis Department of Entomology and Nematology in 2017 after 13 years at the Yale University School of Public Health, New Haven, Conn., first as a postdoctoral fellow from 2004 to 2008, and then as associate research scientist and research scientist.
A native of Poughkeepsie, N.Y., he received his bachelor's degree in entomology from the University of Massachusetts, Amherst, in 1994 and his doctorate in genetics from Michigan State University, East Lansing, in 2004.
(Editor's Note: By popular demand, Attardo plans to again show his virtual reality bugs this year at Briggs Hall during the campuswide UC Davis Picnic Day on Saturday, April 18. "We have some new 3D data showing the internal reproductive organs of the tsetse fly that we plan to adapt to virtual reality.")
Yes? Then you'll want to attend the Science Café presentation on Wednesday, June 7, when medical entomologist and tsetse expert Geoffrey Attardo of the UC Davis Department of Entomology and Nematology will discuss “Got Milk? The Evolution and Biology of the Lactation in the Tsetse Fly.”
The event, set for 5:30 p.m., in the G Street Wunderbar, 228 G St., Davis, Calif., is free and open to the public. Jared Shaw of the UC Davis College of Letters and Science will host the presentation.
“It is actually going to be a very basic talk aimed at lay audiences and kids,” Attardo says. “I'll be talking about my background, how I became an entomologist and how I ended up working on tsetse flies. Then I am going to discuss the life history of tsetse flies, where they can be found, why they are of medical importance and how their reproductive biology differs so dramatically from other flies that people are familiar with. My plan is to go over their reproductive cycle, how they develop intrauterine larvae, the reproductive adaptations that allow them to perform this feat and then go over what we know about tsetse milk secretions and how they compare to mammalian milk in terms of nutritional content.”
“The aim is for it to be very informal, with very little scientific jargon and to be discussion-oriented so that there is lots of questions and answers. I am also bringing some items from the lab that can be passed around the audience for show and tell (homemade tsetse cages, the blood feeding system we use to feed the flies and some tsetse flies preserved in alcohol).
Attardo focuses his research on numerous aspects of the physiology of tsetse fly reproduction, with the goal to identify and understand key aspects of its reproductive biology. He joined the UC Davis Department of Entomology and Nematology in 2017 from the Yale University School of Public Health, New Haven, Conn., where he researched tsetse flies in the lab of Serap Aksoy.
Attardo considers the tsetse fly "one of the champions of the insect world."
"In addition to being vectors of a deadly disease, Trypanosomiasis, these flies have undergone amazing alterations to their physiology relative to other insects," he says. "Some examples of this are their ability feed exclusively on blood, their obligate relationship with a bacterial symbiont, the fact that they lactate and that they give birth to fully developed larval offspring."
If you'd like scientific information on tsetse fly lactation, see Adenotrophic Viviparity in Tsetse Flies: Potential for Population Control and as an Insect Model for Lactation, co-authored by Attardo and published in January 2015 in the Annual Review of Entomology.
The UC Davis scientist was featured in a New York Times' article on tsetse flies on Feb. 12. Pulitzer-Prize winning science writer Natalie Angier penned the article, "Everywhere in the Animal Kingdom, Followers of the Milky Way" (subhead: "As scientists learn more about milk's evolution and compositional variations, they are redefining what used to be a signature characteristic of mammals.")
"Most female flies take a low-rent approach to parenthood, depositing scores of seed-sized eggs in the trash or on pet scat to hatch, leaving the larvae to fend for themselves," Angier wrote. "Not so the female tsetse fly. She gestates her young internally, one at a time, and gives birth to them live. When each extravagantly pampered offspring pulls free of her uterus after nine days, fly mother and child are pretty much the same size."
Then she quoted Attardo: “It's the equivalent of giving birth to an 18-year-old."
Attardo is also a talented macro photographer. He won the 2010 Fogarty Grantee Photo Contest with an image of a tsetse fly. The Yale School of Public Health magazine featured his images on “An Eye for the Tsetse Fly.” The Los Angeles Times published his remarkable video (in 2014) of a tsetse fly giving birth. Also, see his portraits of the tsetse fly on Live Science, published in 2014.
Tsetse fly expert Geoffrey Attardo, a medical entomologist and assistant professor with the UC Davis Department of Entomology and Nematology, drew the attention of Pulitzer-Prize winning science writer Natalie Angier who penned the article, "Everywhere in the Animal Kingdom, Followers of the Milky Way" (subhead: "As scientists learn more about milk's evolution and compositional variations, they are redefining what used to be a signature characteristic of mammals.")
Her lede: "Most female flies take a low-rent approach to parenthood, depositing scores of seed-sized eggs in the trash or on pet scat to hatch, leaving the larvae to fend for themselves."
"Not so the female tsetse fly. She gestates her young internally, one at a time, and gives birth to them live. When each extravagantly pampered offspring pulls free of her uterus after nine days, fly mother and child are pretty much the same size."
Then she quoted the UC Davis medical entomologist:
“It's the equivalent of giving birth to an 18-year-old,” said Geoffrey Attardo, an entomologist who studies tsetse flies at the University of California, Davis.
Attardo focuses his research on numerous aspects of the physiology of tsetse fly reproduction, with the goal to identify and understand key aspects of its reproductive biology. He joined the UC Davis Department of Entomology and Nematology in 2017 from tje Yale University School of Public Health, New Haven, Conn., where he researched tsetse flies in the lab of Serap Aksoy.
In terms of "fascinating physiological adaptations," Attardo considers the tsetse fly "one of the champions of the insect world!" As he explained to us in a 2017 news story: "In addition to being vectors of a deadly disease, Trypanosomiasis, these flies have undergone amazing alterations to their physiology relative to other insects. Some examples of this are their ability feed exclusively on blood, their obligate relationship with a bacterial symbiont, the fact that they lactate and that they give birth to fully developed larval offspring."
"The opportunity to study the adaptations these flies have made is like opening a toy chest for an insect physiologist. My work in tsetse has focused on the molecular biology underlying the adaptations associated with the development of lactation, symbiosis, male and female mating interactions/physiology and nutrient metabolism and mobilization.”
Attardo's published research is drawing national and international attention, as are his incredible images of tsetse flies. He won the 2010 Fogarty Grantee Photo Contest with an image of a tsetse fly. The Yale School of Public Health magazine featured his images on “An Eye for the Tsetse Fly.” The Los Angeles Times published his remarkable video (in 2014) of a tsetse fly giving birth. Also, see his portraits of the tsetse fly on Live Science, published in 2014.
In her New York Times article, Angier points out that "Only in the class Mammalia do all member species nurse their young, yet evolutionary biologists now believe that the roots of mammalian lactation date back more than 300 million years, a good 100 million years before the first mammals appeared."
And while on the subject of tsetse flies, be sure to read the September 2016 article, "Tsetse Flies Are Strange and Dangerous," by Kevin Fitzgerald in Entomology Today, a publication of the Entomological Society of America. Fitzgerald featured the work of Attardo and posted one of his photos.