Graduate students and postdoctoral students that the legendary John Casida trained remember him with great fondness, respect and appreciation.

He made a difference: a huge difference.

Dr. Casida, 88, a world-renowned entomologist and toxicologist at UC Berkeley who died June 30 of a heart attack in his home, was a global authority on how pesticides work and their effect on humans.

A distinguished professor emeritus of environmental science, policy and management and of nutritional sciences and toxicology, Dr. Casida was the founding director of the campus's Environmental Chemistry and Toxicology Laboratory.

When awarded the Wolf Prize in Agriculture in 1993, the Wolf Foundation lauded his “research on the mode of action of insecticides as a basis for the evaluation of the risks and benefits of pesticides and toxicants, essential to the development of safer, more effective pesticides for agricultural use." according to a UC Berkeley News Service story. "His discoveries span much of the history of organic pesticides and account for several of the fundamental breakthroughs in the fields of entomology, neurobiology, toxicology and biochemistry.”

Former graduate student Bruce Hammock, now a distinguished professor at the University of California, Davis, who holds a joint appointment with the UC Davis Department of Entomology and Nematology and the UC Davis Comprehensive Cancer Center, remembers him as a “lifelong mentor who evolved into a colleague and a friend.”

“John probably had a greater impact on his field of pesticide toxicology than any scientist of his generation,” said Hammock,  founding director (1987-present) of the UC Davis NIEHS (National Institute of Environmental Health Sciences) Superfund Research Program and 25-year director of the UC Davis NIH/NIEHS Combined Analytical Laboratory. “His laboratory at Berkeley provided me with the most exciting years of my scientific career.  In his own work, John moved from strength to strength creating numerous entire fields along the way. His scientific insight and drive were a constant stimulation to drive for innovation and excellence. Whenever I had an opportunity, I encouraged others to join his team. John was an inspiration and role model, not only because John came in early and stayed late, but also because he did science for the fun of discovery and taught for the joy of teaching.”

“John continued his high productivity until his death with major reviews on pesticides in 2016, 2017, and 2018 in addition to numerous primary papers,” Hammock noted. “He was working on primary publications as well as revising his toxicology course for the fall semester at the time of his death. Pesticide science was the theme of his career, and we live in a world with far safer and more effective pest control agents because of his effort.”

Professor John Casida opened multiple new fields ranging from fundamental cell biology through pharmaceutical discovery. "He pioneered new technologies throughout his career, from being one of the first to use radioactive compounds for pesticide metabolism through studies with accelerator mass spectrometry, photoaffinity labeling and others," Hammock related. "Yet the greatest impact of his career probably lives on in the numerous scientists he trained, now carrying on his traditions of excellence in science. These scientists are around the world in governmental, industrial and academic careers.”

Sarjeet Gill, Distinguished Professor, UC Riverside

“It was clear to me the day I arrived at UC Berkeley that I had to work with John," quipped former graduate student Sarjeet Gill of the Casida lab, now a distinguished professor at UC Riverside. "I remember walking into his office and indicating that I would like to work with him. His response, very Johnlike: 'How are you going to support yourself?' When I indicated I had a UC Berkeley fellowship, John gave me a trial project to test my abilities. I then knew, early on, that I needed to have my act together. He then gave me the freedom to make mistakes, allowing me to work through misadventures but correcting them as needed, ultimately leading to a successful project.

"This project also allowed me to build a long lasting friendship with Bruce Hammock who also was on the same project. Since John was always very focused, I often challenged John's patience with my practical jokes. I am sure he knew who the culprit(s) were but he never revealed he knew.

“The research experiences in John's lab made an indelible impression on me that drove me to return to the United States from Malaysia for an academic career in the UC system. Personally, I have lost an incredible mentor, and the scientific community lost the most preeminent pesticide toxicologist in the last two centuries. John changed the way we investigated mechanisms of toxicity at all levels. I certainly will miss him dearly.

Bruce Hammock, Distinguished Professor, UC Davis

"My mentors from Louisiana State University told me there was only one toxicologist to work for as a PhD student," recalled Bruce Hammock. "I had money to apply to only one university, so I headed west in 1969 to study with John Casida (without informing him). I had the misfortune to arrive in John's laboratory several hours after Sarjeet Gill. In the basement of Wellman Hall, I spied a man in a lab coat from whom I inquired the location of Professor Casida. He replied: 'Let's see if we can find him,' and continued looking in cabinets filled with bottles. He soon found a bottle, pocketed it, walked into an office at the end of the hall and announced, 'We have found him.'

"After telling him I was there to be his graduate student, he replied he had no money for students. My retort was that I had a fellowship. He then told me that students were not space effective, and I promised not to take up much space. He continued that students were not time effective, and I promised not to take his time. In retrospect, Sarjeet must have really soured him on graduate students a few hours earlier."

"Months later, Sarjeet and I were sharing a desk-lab bench in the windowless closet next to the 'fly room' when Dr. Casida walked in. He had noted we both listed him as our major professor and asked if there was anything, he could do to encourage us to leave. When in unison we replied 'No!,' he politely left without accepting us, but soon we both had a desk and bench.

"So a few paces after Sarjeet, I initiated the most thrilling four years of my life. John's introduction to experimental science was marvelous with the perfect balance of inspiration, instruction and tremendous freedom. I was privileged to learn from a wonderful group of individuals and, of course, I made my most enduring of friendships with Sarjeet Gill. In addition to science, John taught a life-family-science balance by example. John was my life long mentor in science and in life but also evolved as a colleague and friend.

"Three more delightful years passed and John then took me to lunch at the faculty club. As I was about to leave the laboratory for the U.S. Army, he gave me sagely advice such as he had had it easy during the Sputnik period and I would have it hard. Then he went on to tell me than most people in the laboratory did not find my practical jokes nearly as funny as I did. I did not reveal that Sarjeet had both planned and executed most of them. Thus, Sarjeet succeeded in disrupting my Berkeley career from beginning until the end.

"John and his laboratory at Berkeley provided me with the most exciting years of my scientific career.  In his own work, John moved from strength to strength creating numerous entire fields along the way. His scientific insight and drive were a constant stimulation to drive for innovation and excellence. Whenever I had an opportunity, I encouraged others to join his team. John was an inspiration and role model, not only because John came in early and stayed late, but also because he did science for the fun of discovery and taught for the joy of teaching."

Professor Casida is survived by his wife, artist and sculptor Kati Casida, sons Mark and Eric Casida, and two grandchildren.

(See more remembrances by UC Davis-affiliated scientists trained by Professor Casida on the UC Davis Department of Entomology and Nematology website)

Related Information:

• John Casida Obituary, UC Berkeley News Service
• For the Fun of Science: A Discussion with John E. Casida (Archives of Insect Biochemistry and Physiology)
• ​Still Curious: An Overview of John Casida's Contributions to Agrochemical Research (JAFC)
• ​Curious about Pesticide Action, by John E. Casida (JAFC)

(UC Berkeley New Service contributed to this post)

So there they were, literally dozens of dragonflies flying around two separate Vacaville (Calif.) yards, feasting on swirling clouds of prey (gnatlike insects) and then touching down on blades of grass or fence posts.

They proved as elusive as a celebrities attempting to avoid a paparazzi.

Dragonflies, but what species?

Bohart Museum of Entomology associate Greg Kareofelas of Davis identified them as variegated meadowhawks, Sympetrum corruptum. "Notice how the pterostigma is two-toned," he said. "That is the only dragon with that, also the two black spots at the end of the tail. They kind of migrate--or maybe mass dispersal is a better name.  A bunch can show up if there is something to eat, then the whole gaggle moves on."

The pterostigma cell, located in the outer wing of insects, is often thickened or colored and so it stands out from other cells, according to Wikipedia. It is particularly noticeable in dragonflies, but is also present in other insect groups, such as snakeflies, hymenopterans and megalopterans.

"The male is commonly dark brownish black with an abdomen of bright red, pink, and golden brown," Wikipedia relates. "The thorax may be marked with a pair of yellow dots on each side. The leading edges of the wings are marked with pinkish. The females are similar in color but not as brightly colored, with gray and yellow replacing the red of the male. Young variegated meadowhawks are much paler and mottled with pale green, pale yellow, golden brown, and orange."

According to Odonata Central, "this species may be seen on the ground more than other meadowhawks. It will also readily perch on the tips of grass stems and tree branches. It can be numerous flying over roads, lawns, meadows, marshes and ponds...Mating occurs while perched on twigs, stems or other vegetation. Females lay eggs accompanied by males in the open water of ponds and lakes. Mass movements of this species have been reported on several occasions."

The variegated meadowhawk, native to North America, belongs to the family, Libellulidae. They're found throughout the United States and southern Canada, according to Odonato Central. "Also, Mexico south to Belize and Honduras."

Coming soon to a yard near you?

The late medical entomologist William Emery Hazeltine II (1926-1994) worked tirelessly in mosquito research and public health.

Thanks to the generosity of his family, his work is continuing through memorial research grants to outstanding graduate students at the University of California, Davis.

Hazeltine, a native of San Jose, was a U.S. Navy veteran who studied entomology at UC Berkeley and received his doctorate in entomology from Purdue University in 1962. He managed the Butte County Mosquito Abatement District, Oroville, from 1966 to 1992, and the Lake County Mosquito Abatement District from 1961-1964.

He was an ardent supporter of the judicious use of public health pesticides to protect public health, remembers Bruce Eldridge, emeritus professor of entomology at UC Davis and former director of the (now folded) statewide UC Mosquito Research Program. Eldridge eulogized him at the 2005 annual meeting of the American Mosquito Control Association (AMCA) as "a man who made a difference." The AMCA journal published his eulogy in its 2006 edition.  (See http://entomology.ucdavis.edu/files/154217.pdf)

"Bill was a medical entomologist who had a varied career in the field of mosquito biology and control, but he will forever be remembered as a man who fought in the trenches of the pesticide controversy from 1960 until the end of his life, and who made the safe and efficient use of pesticides in public health a personal crusade," Eldridge said.

In his memory, his three sons--Craig Hazeltine of Scottsdale, Ariz., Lee Hazeltine of Lincoln, formerly of Woodland, and the late Jeff Hazeltine (1958-2013)—established the UC Davis Bill Hazeltine Graduate Student Research Awards in 1997. Each year they travel to Davis to honor the recipients at a luncheon, timed with their attendance at a scholarship and fellowship celebration, hosted by Dean Helene Dillard, UC Davis College of Agricultural and Environmental Science.

The 2017 recipients are

• Olivia Winokur of the Christopher Barker lab, Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine. Her funded project ($2425): “Identifying Aedes Mosquito Eggs Using Hyperspectral Imaging: a Rapid, Low-Cost, Non-Destructive Method to Improve Mosquito Surveillance and Control.”
• Maribel "Mimi" Portilla of the Sharon Lawler lab, UC Davis Department of Entomology and Nematology. Her funded project ($2032): “The Management of Invasive Weeds and their Effects on Larval Culex mosquitoes."

Winokur is also the newly announced 2018 recipient of $3,094 to investigate Aedes aegypti immune response to Zika virus.  (Portilla expects to receive her doctorate in six to 12 months.)

Olivia Winokur

Olivia Winokur received her bachelor's degree in 2015 from Cornell University, majoring in Interdisciplinary Studies and focusing on the environmental effects on human health. She enrolled in the UC Davis graduate program in 2016 as a Ph.D entomology student with a designated emphasis in the biology of vector-borne diseases. Earlier this year, Winokur received a three-year National Science Foundation Graduate Research Fellowship.

“Aedes aegypti and Aedes albopictus are mosquitoes capable of transmitting dengue, chikungunya, yellow fever, and Zika viruses,” Olivia Winokur explained in her 2017 application. “These species are invasive and present in California and continue to spread, increasing the likelihood of local transmission of these devastating viruses. Additionally, Aedes notoscriptus, an Australian mosquito whose vector competence for many viruses is unknown, has been detected in Los Angeles and is likely to spread in the state.  Aedesmosquitoes are readily detected using ovitraps, a cheap and effective sampling method to detect the presence of gravid females. Ovitraps are especially useful when mosquito populations are low as traps for adult Aedes are unreliable. Once collected, the eggs cannot be differentiated using a stereomicroscope. Traditionally, identifying Aedes eggs collected in ovitraps requires hatching and rearing to adult for visual identification, which is time consuming and leads to a time lag for control, potentially allowing invasive species to spread without intervention.” 

“Currently, I am developing a non-destructive, low-cost method to rapidly identify Aedes eggs,” Winokur wrote. “I have shown that species-specific surface morphologies of the exochorion can be used to differentiate species using electron microscopy. This method is expensive and therefore not a realistic surveillance technique. We can, however, exploit these species-specific surface morphologies in another way to identify Aedeseggs. Slight changes in morphological characteristics can be captured with high spatial resolution proximal sensing imaging, termed hyperspectral imaging.” 

Winokur is testing “the use of  hyperspectral imaging to differentiate between eggs collected from lab colonies of native and invasive Aedes mosquitoes in California. Preliminary data indicate this method shows promise for identifying species and warrants further testing.  Once I have created species-specific reflectance profiles and validated my identification method using colony eggs, I will collect field eggs and validate the identification method using these field eggs.” She is working with  hyperspectral imaging expert Christian Nansen, agricultural entomologist and assistant professor, UC Davis Department of Entomology and Nematology, on the project.

Winokur describes hyperspectral imaging as “a powerful tool that recognizes slight changes; therefore, we need to ensure that all samples are collected and conditioned the same way before testing. Samples must be imaged directly on the oviposition paper because exochorion cells are damaged by the ‘glue' the female uses to attach her eggs to the substrate; imaging removed eggs leads to inconsistent reflectance profiles. This method for rapidly identifying Aedes eggs will allow for quick response to the detection of invasive Aedes mosquitoes.”

After finishing her Ph.D., Winokur plans to remain in academia, but “I'm unsure exactly what that will look like! I really enjoy research, teaching, and mentoring so I'd like to have a career where I can do all of these. I also plan to have a career where I can conduct translational research with broad global health implications, engage non-scientists, create tools to help decision makers mitigate vector-borne disease burden worldwide, and encourage interest and diversity in STEM (science, technology, engineering and mathematics).” 

Maribel "Mimi' Portilla

Mimi Portilla, who joined the UC Davis Entomology Graduate Program in the fall of 2012,  holds a master's degree in public health from UC Berkeley, where “I was able to study health and disease within a larger context, and learned to consider the biological and the social determinants of disease.” Her area of expertise incorporates her love for biology and her strong interest in social issues.

“At UC Berkeley School of Public Health, I was able to study health and disease within a larger context, and learned to consider the biological and the social determinants of disease. As I completed my degree, I realized I really missed the research experiences I had as an undergraduate. So, I looked for a way to bridge my new-found passion for public health and basic science research. This led me to UC Davis, where I learned about One Health and am now pursuing a Ph.D in medical entomology. Medical entomology is a perfect example of a One Health field, where I can seek out how interactions between humans and animals impact health. I am particularly interested in researching how disease risk may change as people manipulate the environment."

Her academic life revolves around writing her dissertation; teaching UC Davis classes (she's taught entomology, general biology and One Health classes); research; and public outreach. Since 2012, she has mentored some 30 undergraduate students on developing and executing their research experiments. She praised the “the diversity of my interns; they each brought such important and unique perspectives to the project.”

What are her career plans?

“Due to my diverse interests and skill set, I am very open about my career choices," Portilla said. "I have extensive teaching experience, and would love to be a professor with both teaching and research opportunities. However, there are many opportunities beyond academia. My research is introducing me to many other ways in which my work and research can help keep people safe and healthy. I hope to develop a strong research skill set while at UC Davis, and find a career path which takes advantage of my diverse abilities and love for One Health and Public Health."

Portilla mentioned pursuing a career as a teacher in a small liberal arts school to teach public health, general biology and global diseases classes, as well as do outreach and research. “I'm more of a scientist than an entomologist,” she said.

She may also pursue a career working in vector-control health education at the county, district or state level. “I'm open at this point,” Portilla said. Overall, she is geared toward improving public health outcomes through healthier environments. “I care about how outcomes affect the larger population,” she said.

Meanwhile, it's good to see that William Emery Hazeltine's passion for medical entomology lives on, and to see UC Davis graduate students benefit, all thanks to the generosity and thoughtfulness of the Hazeltine family. The "family" of 42 recipients since 1997 includes Christopher Barker, Winokur's major professor, who received a Hazeltine research award in 2006.

The complete list of recipients:

• 2018: Olivia Winokur (newly announced)
• 2017: Maribel "Mimi" Portilla and Olivia Winokur
• 2016: Sandy Olkowski, Maribel “Mimi” Portilla and Stephanie Kurniawan
• 2015: Sandy Olkowski, Maribel “Mimi” Portilla and Stephanie Kurniawan
• 2014: Martha Armijos, Elizabeth “Lizzy” Glennon and Rosanna Kwok
• 2013: Jenny Carlson, Elizabeth “Lizzy” Glennon and Sandy Olkowski
• 2012: Jenny Carlson, Kelly Liebman and Sandy Olkowski
• 2011: Brittany Nelms Mills, Kelly Liebman and Jenny Carlson
• 2010: Tara Thiemann and Jenny Carlson
• 2009: Kelly Liebman and Wei Xu
• 2008: Ashley Horton and Tara Thiemann
• 2007: Lisa Reimer and Jacklyn Wong
• 2006: Christopher Barker and Tania Morgan
• 2005: Nicole Mans
• 2004: Sharon Minnick
• 2003: Hannah Burrack
• 2002: Holly Ganz and Andradi Villalobos
• 2001: Laura Goddard and Linda Styer
• 2000: Laura Goddard
• 1999: Linda Boose Styer
• 1998: Larisa Vredevoe
• 1997: John Gimnig

Irish novelist Margaret Wolfe Hungerford was right.

In Molly Bawn, published in 1878, Hungerford wrote "Beauty is in the eye of the beholder," meaning that our perception of beauty is subjective.

Beauty is also in the eye of the bee-holder, that is, a predator that "holds" bees.

We recently spotted a crabronid wasp (genus Philanthus) foraging on a pineapple sea lily (Eryngium horridum). 

This solitary, digger wasp is better known by its common name, beewolf. That's because it preys on bees, including honey bees. The wasp stings the bee with its powerful venom, paralyzing it. Then it flies off with the bee (alive) to its underground nests where it provisions its cell burrows for its young.

"They are notable in stinging their prey in a membranous location on the ventral surface where the venom quickly paralyzes major voluntary muscles, yet does not kill the prey," according to Wikipedia. "The prey may attempt to sting in return, but it is always grabbed in such a way that only well-armored portions of the beewolf's body are presented. The beewolf carries the prey back to a tunnel, but usually only stores it temporarily, until it is later used to provision a cell burrow, where an egg is laid."

As we watched the beewolves (as identified by Lynn Kimsey, director of the Bohart Museum of Entomology and professor of entomology at the University of California Davis) we also saw other critters foraging on the pineapple sea lily: honey bees and assorted mordellid beetles.

Take a look the beewolf. Note the bold, black stripes on the abdomen; the brilliant yellow on the head and thorax; and those sea-green eyes.

It's a predator, but predators, like prey, can be strikingly beautiful. Beauty is in the eye of the bee-holder.