DAVIS--There aren't many medical entomologists who have done what William “Bill” Reisen has done or what he will do. 

Internationally known for his mosquito research and publications spanning more than four decades, Bill Reisen officially retired in July from the University of California, Davis, but mosquitoes shouldn't breathe a collective sigh of relief and go about their blood-sucking business. 

Reisen, now a professor emeritus with the Department of Pathology, Microbiology and Immunology (PMI), School of Veterinary Medicine, vows to continue his mosquito research; manage the vector-borne disease surveillance diagnostics lab; advise graduate students in the School of Veterinary Medicine; mentor several new PMI faculty members; direct the Center for Vectorborne Diseases (CVEC) and edit the Journal of Medical Entomology. In between, he and his wife Norma will travel throughout the United States and Europe and to their mango farm in the Philippines. 

And along the way, he'll probably encounter the 10 species mosquitoes that he developed a close and personal relationship with--“skeeters” that transmit diseases such as malaria, yellow fever, encephalitis and West Nile virus.  

While other people count sheep to go to sleep, Reisen probably counts mosquitoes at his current or former research sites:

Pakistan? Culex tritaeniorhynchus, Anopheles stephensi and Anopheles culicifacies

Nepal? Anopheles fluviatilis and Anopheles maculatus

California? Culex tarsalis, Culex pipiens complex, Culex stigmatosoma, Aedes dorsalis and Aedes melanimon 

Meanwhile, the accolades flow. 

"Bill Reisen is an international leader in mosquito ecology and arbovirus epidemiology,” said Professor Thomas Scott of the UC Davis Department of Entomology and Nematology and a worldwide expert on the dengue mosquito. “His contributions to his field of study are stunning.  His prolific, detailed field and laboratory studies have reshaped the way we think about mosquito-borne pathogen transmission dynamics.  He has greatly improved disease prevention programs.” 

 “And,” Scott added, “he is a genuinely good person.  For those of us fortunate enough to have worked with him, Bill is recognized for the exceptional rigor of his science and uniquely high quality of his character." 

Colleague Bruce Eldridge, emeritus professor of entomology at UC Davis, described Reisen as “the hardest working and most dedicated entomologist I have ever had the pleasure of working with.  Nearly everything he does has a definite purpose, and the results of his research have improved substantially our ability to protect people from vectorborne diseases both here in California and elsewhere in the world.” 

“He has also instilled these principles of hard work and concentration on important subjects to study in a long list of graduate students, post-doctoral researchers, and other visiting scientists. People go to Bill all the time for advice and other kinds of help.  He never says no. He is a remarkable individual, and I know he won't quit doing the things he does just because he is retiring.” 

Reisen is the newly selected editor-in-chief of the Journal of Medical Entomology, published by Entomological Society of America (ESA). He had earlier served as a co-editor from 1988 to 2000 and subject editor since 2000.  The journal, published bimonthly, focuses on all phases of medical and veterinary entomology and acarology, including the systematics and biology of insects, acarines (mites and ticks), and other arthropods of public health and veterinary significance. In addition, Reisen has served as a member of the editorial board of the Journal of Science and Climatic Change, since 2010 and Vectorborne and Zoonotic Diseases since its inception. 

A native of New Jersey, Reisen holds a doctorate in zoology (1974) from the University of Oklahoma, Norman, with a focus on medical microbiology and ecology.

Young Bill began his academic career as an undergraduate in entomology at the University of Delaware in 1963 and as a research assistant with Clemson University in 1967, monitoring organochloride insecticide residues in fish and aquatic insects. As a teaching assistant at Clemson, he taught animal ecology in 1968 and continued his research on stream ecology and fish-feeding behavior. 

Reisen served as a captain in the U.S. Air Force from 1969 to 1971. He was assigned to the 5th Epidemiological Flight, Manila and 1st Medical Service Wing, Clark Air Base,  Republic of the Philippines. His duties included vector-borne disease surveillance and control programs on USAF Bases in Pacific Air Command, which took him on  temporary duty to Japan, Taiwan, Korea, Okinawa, Thailand, Guam and Hawaii. 

Reisen resumed his academic career from 1971 to 1974 when he taught entomology, zoology, ecology and parasitology courses as a teaching assistant at the University of Oklahoma. He then worked as a research associate from 1974 to 1975 at the University of Maryland School of Medicine, where he did research on a malaria mosquito, Anopheles stephensi, and assisted David Clyde during the first malaria vaccine trials in humans. 

In 1975 Reisen was assigned to the University of Maryland School of Medicine's Pakistan Medical Research Center in Lahore, Pakistan, where he served as an assistant professor of international medicine from 1975 to 1980 and headed the Ecology Department. His research involved population ecology and the bionomics of Pakistani mosquitoes and their relation to pathogen transmission and field trials related to genetic control of mosquitoes. 

Reisen moved to California in 1980 to become research entomologist and director of the Arbovirus Field Station of the UC Berkeley School of Public Health in Bakersfield. “I worked on population ecology, bionomics, genetics and vector competence of Culex tarsalis in relation to arbovirus ecology and control in California until 1995,” he said. The program later transferred to the UC Davis School of Veterinary Medicine in 1996 and CVEC was born.  

Reisen remained in Bakersfield until 2005 when he moved to the UC Davis campus and later became director of CVEC in September 2009 and a PMI adjunct professor in 2005.  With the Arbovirus Research Program, he continues to focus his work not only on mosquitoes but people. He has supervised up to two postdoctoral students, four Ph.D. students, one associate specialist entomologist, a computer programmer, four staff research associates, two laboratory assistants and two undergraduate student assistants.  

“My career can be divided into three phases: (1) education/learning, (2) field research and (3) advising and mentoring,” Reisen said.  “Graduate training at Clemson and Oklahoma and my U.S. Air Force assignments in southeast Asia and my position in Pakistan provided a great introduction to how to do field studies and work in remote areas with minimal equipment and support.  This training was applied during the 25 years in Bakersfield where we did everything from genetic control trials to host and vector competence studies with several arboviruses.” 

“This training and work experience managing integrated field research programs gave me insight on how to mentor graduate students and new faculty, the final phase of my career,” Reisen noted. “The latter experience expanded our research breadth and improved our program immeasurably as I got to know some very bright and engaging students.  Throughout my career I was very fortunate to be supported by excellent laboratory and field staff which formed the cornerstone of our NIH-funded research programs.”   

Highly honored by his peers, Reisen has received national and international honors that include:

• Lifetime Award for Achievement in Medical Entomology, Society for Vector Ecology, presented at the International Congress, 2001.
• Fellow, Entomological Society of America, 2003.
• Academic Federation Award for Excellence in Research, UC Davis, 2004.
• John N. Belkin Award for Excellence in Vector Ecology, American Mosquito Control Association, 2006
• Distinguished Service Award, Society for Vector Ecology, 2006
• Harry Hoogstraal Medal, American Society of Tropical Medicine and Hygiene, 2012 

Reisen is a past president of the Society for Vector Ecology and chaired the ESA's D Section and the Publications Council.  He also chaired a number of subcommittees, including the Disease Control Subcommittee, of the California Mosquito and Vector Control Association, and headed the Vector Control Advisory Committee of the California Department of Health Services (CDHC), among other leadership activities. 

Reisen's work includes 297 peer-reviewed research publications, plus book chapters.

Since 1984, Reisen has guided seven Ph.D. and postdoctoral students: Mark Eberle, UC Berkeley School of Public Health, and Carrie Nielsen, Christopher Barker, Jennifer Kwan, Gabriella Worwa, Tara Thiemann and Sarah Wheeler, UC Davis. He currently serves as the major professor for two graduate students in Comparative Pathology: Veronica Armijos[rev1] , also manager of the Thomas Scott lab in the Department of Entomology and Nematology, and Andra Hutton.

Chris Barker, now an assistant adjunct professor with PMI and CVEC, said that Reisen is “known to virtually everyone who has spent much time studying mosquitoes or the viruses they transmit.” 

“Bill has had a very productive and well-documented career represented in his 297 peer-reviewed scientific papers,” Barker said. “His lasting enthusiasm for his work, good humor, and uncommon humility have been an inspiration to all of his colleagues, especially the students and staff who have had the good fortune to be a part of his research program. One unique aspect of Bill's career is that he spent over 30 years in the field and at the lab bench in contact with mosquitoes almost daily, which is increasingly rare in today's world of digital data collection. It is safe to say that Bill will not quit upon retirement, and his intellectual input and wealth of experience will continue to be valued for years to come.”

Sarah Wheeler participated in the “West Nile virus period” of Reisen's career-- first as a technician, then as a PhD student, and finally, as a post-doctoral scholar. “During the West Nile period Bill facilitated and conducted a body of work leading to the understanding of West Nile virus transmission and overwintering in California. Bill's dedication to the field of arbovirology and fierce work ethic inspired me to follow in his footsteps, and along the way he shaped my approach to science through his lead by example style. Bill has been a fabulous mentor and I am unendingly grateful I took his original job offer that sent me out into the middle of nowhere, but opened upon the world of arbovirology.”

Said Reisen: “Although we did spend a lot of time collecting mosquitoes, we also had a large bird program where we collected, bled and tested more than 85,000 wild bird sera for arbovirus infection and did a host of experimental infection studies with birds ranging from house finch nestlings to adult mallard ducks and black-crowned night herons.”

Robert Washino, emeritus professor and former chair of the UC Davis Department of Entomology and a former administrator with the UC Davis College of Agricultural and Environmental Sciences, lauded Reisen's career.

“Bill has had a very colorful career in medical entomology,” said Washino.  He remembers visiting his laboratory at the School of Medicine, Lahore, Pakistan “in another lifetime.” 

“Bill's work on several important malaria anopheline vectors in that country constituted important contributions and also included studies on Culex tritaeniorhynchus, the vector of Japanese Encephalitis virus, somewhat comparable to Culex tarsalis, the vector of several arboviruses in the western U.S.,” Washino said. 

“Bill will forever be remembered as the continuing lead investigator of the important W. C. Reeves, UC Berkeley arbovirus program in California,” Washino said. He praised Reisen's collaborative work with the California Department of Public Health and local regulatory agencies of the Mosquito and Vector Control Association of California.

As for Bill Reisen, “the retiree,” he says he's looking forward to continuing his myriad of mosquito-related activities “to finish up my career and help protect the health of the citizens of California.”

“My final objective,” he said, in typical Reisen humor, “is to learn to play bogey golf.” 

A new online publication, "FAQ: West Nile Virus," the work of 22 scientists selected by the American Academy of Microbiology, including UC Davis research entomologist William Reisen, tells why the mosquito-borne disease is on the rise and why the summer of 2012 was the worst national outbreak since 2002.

The Centers for Disease Control and Prevention (CDC) recorded 2,873 cases in 2012, including 286 deaths. The disease is now "established" in the United States and is here to stay, according to the CDC.

Where did WNV virus come from? How is it spread? Can we predict when and where outbreaks will occur?

Those are some of the questions answered in the academy's free online publication. A video is also posted on that web site.

The Academy convened 22 of the world’s leading experts on West Nile virus in March 2013 to consider and answer some of the most frequently asked questions about West Nile virus. The resultant report provides non-technical, science-based answers to questions that people may have about the virus.

William Reisen, internationally renowned for his comprehensive research on mosquitoes, especially those that transmit encephalitis and WNV, was one of two experts from the systemwide University of California consulted for the publication. The other was Philip Norris, a physician with the Blood Systems Research Institute and UC San Francisco.

Reisen directs the UC Davis-based Center for Vectorborne Diseases, and is a professor in the Department of Pathology, Microbiology and Immunology and a graduate student advisor with the UC Davis Department of Entomology and Nematology. Last year he received the international Harry Hoogstral Award for “outstanding achievements in the field of medical entomology.”

Questions on the online publication include:

1. West Nile virus in the news: what happened in 2012?

2. How did WNV get to the United States?

3. How did WNV spread across the country so quickly?

4. How do people get infected with WNV?

5. Why do some people get West Nile fever or neuroinvasive disease? Did they become infected with a “bad” virus?

6. Why was 2012 so bad?

7. If we know what conditions cause WNV outbreaks, can we predict when a new outbreak will emerge and what its severity might be?

WNV, initially discovered in Uganda, is transmitted by the bite of an infected mosquito. It was first detected in the Americas--New York City--in 1999. Within four years, the disease had spread to every state in the contiguous United States.

The publication indicates that "your risk of developing West Nile fever or neuroinvasive disease greatly increases with age and if your infection is transplant tissue associated. In fact, the risk of WNND increases roughly two times for every decade of life. For the younger population, less than 1 in 700 will develop neurological symptoms, but this ration increases to as much as 1 in 50 in those aged 60 or older."

In 2012, "the central United States reported the highest number of West Nile severe disease cases, with Texas shouldering 29 percent of the disease burden. In fact, what made the Texas outbreak so striking is that just four counties in the Dallas/Fort Worth area accounted for 9012 out of 1,868 total reported West Nile cases in the state. Other states hit with large West Nile outbreaks were California, Illinois, Louisiana and Michigan--together the top five states suffered 56 percent of the reported national neuroinvasive disease cases."

DAVIS--Brittany Nelms, who recently completed her doctoral work in entomology at UC Davis and  is now the entomologist for the Lake County Vector Control District (LCVCD) in Lakeport, Calif., will present the next UC Davis Department of Entomology seminar.

Nelms will present her exit seminar on "Overwintering Biology of Culex Mosquitoes in California and Their Potential Role as Overwintering Reservoirs of West Nile Virus" from 12:05 to 1 p.m., Wednesday, May 8 in Room 1022 of the Life Sciences Addition, corner of Hutchison and Kleiber Hall drives.

She will be introduced by her major professor, William Reisen of the  Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, and research entomologist with the Center for Vectorborne Diseases.

Nelms finished her doctoral work in entomology, emphasis in the biology of vectorborne diseases, last December. As the LCVCD entomologist, she helps plan and conduct the district’s research and surveillance program for various arthropod vectors and vectorborne diseases.

Nelms has  presented and published many articles in the Proceedings and Papers of the Mosquito and Vector Control Association of California and co-authored several peer-reviewed publications.  She published her first primary author, peer-reviewed research paper, "Experimental and Natural Vertical Transmission of West Nile Virus by California Culex (Diptera: Culicidae) Mosquitoes,” in the March, 2013 issue of the Journal of Medical Entomology. 

As a graduate student at UC Davis, she received the William C. Reeves New Investigator Award from the Mosquito and Vector Control Association of California; the Bill Hazeltine Student Research Award; and recently was the runner-up for first-place in the American Mosquito Control Association's Student Paper Competition.

“My dissertation research addressed the overarching hypothesis that West Nile virus (WNV) persists within infected, overwintering Culex females until the termination of diapause and/or quiescence renews blood feeding and horizontal transmission,” Nelms said in her abstract. “I addressed this hypothesis with three specific aims. 

“First, the persistence of WNV during winter in mosquito hosts was explored by determining the overwintering strategies of Culex females, delineating the environmental cues utilized in the induction and termination of diapause, and detecting WNV in field-collected overwintering mosquitoes. 

“Secondly, the ability of California Culex females to vertically and transstadially transmit WNV to overwintering progeny was investigated during autumn to determine the frequency of field infection and vertical transmission at foci of active WNV transmission. 

“Third, the vector competence and biology of Culex pipiens f. molestus and f. pipiens females were compared in the laboratory to determine their respective roles as amplification and overwintering vectors of WNV.   Overall, I found that Culex tarsalis and Culex stigmatosoma entered and maintained diapause under both field and experimental conditions, whereas members of the Culex pipiens complex remained reproductively active (f. molestus) or entered quiescence (f. pipiens).  All species were competent vectors of WNV and able to transmit both horizontally and vertically.   Therefore, WNV may overwinter in infected Culex that remain reproductively active, enter reproductive diapause or become quiescent during cool weather.”

Dec. 8, 2010

DAVIS—William Emery Hazeltine II (1926-1994) worked tirelessly in mosquito research.

He managed the Butte County Mosquito Abatement District, Oroville, from 1966 to 1992. He was an ardent supporter of the judicious use of public health pesticides to protect public health.

Hazeltine studied entomology in the UC Berkeley graduate program, 1950-53, and received his doctorate in entomology from Purdue University in 1962.

He managed the Lake County Mosquito Abatement District from 1961-64 and the Butte County Mosquito Abatement District from 1966-1992. He continued work on related projects until his death in 1994.

Bruce Eldridge, emeritus professor of entomology at UC Davis, eulogized him at the 2005 annual meeting of the American Mosquito Control Association (April 4) as "a man who made a difference." His talk, illustrated with photos, was published in the 2006 edition of the Journal of the American Mosquito Control Association.  (See PDF)
"He 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.

Eldridge noted that Hazeltine "was an advocate for the use of mosquito control to protect people from mosquitoes and the disease agents they transmit, and he believed chemical control to be a necessary part of the means to accomplish this. He also considered himself an environmentalist, and billed himself as such on his business cards and on his signature block. He had a vast knowledge of pesticides and pesticide legislation, and a strong belief in the scientific basis for public policy issues related to the safe and effective use of pesticides. Because the federal Endangered Species Act influenced mosquito control, he became an authority on this as well."

William Hazeltine in U.S. Navy, 1944.

Eldridge described Bill as "an effective manager and leader at Butte County. Those who took the trouble to get to know him developed a strong allegiance to him. Most appreciated his absolute honesty and fairness. Not only was Bill honest to a fault, he expected it of people who work for him as well."

Hazeltine's message about pesticides never strayed, Eldridge sad. His positions on pesticide use and regulation included:

1. Decisions on pesticide use should be made by competent people and based on good data

2. Biological contorls are good, and must be used, but chemicals are also necessary for an effective program.

3. When you discuss pesticides, do not stipulate to something just to get acceptance.

4. There is a real need for continuing educaiotn, which is a mark of professionalism.

In closing, Eldridge said that much of AMCA's current involvement with federal legislation affecting mosquito control stems from Hazeltine's work.

Hazeltine, born Sept. 4, 1926 in San Jose, was the youngest of six children born to Karl Snyder Hazeltine and Rachel Josephine Crawford Hazeltine. Karl, a graduate of the University of California, served on the faculty of San Jose State University, where he taught agricultural and natural science. Rachel, a graduate of San Jose State, was a teacher.

William Hazeltine's son, Craig, of Scottsdale, Ariz: commented: "Three recollections: Dad grew and changed over the years. The reports may cast him as a constant iconoclast, but he learned to love and be loved. When I became a Christian in college, I felt compelled to tell my Dad 'I love you' often and to back it up with a hug. He was like a stiff board at first, but later on was almost a menace with his wonder hugs.

"Dad was not so gruff as he was 'occupied.' I figured out early on that the best way to spend time with him was to help him with his projects--and there was always something in the works. He was always reading, studying, and trying new things.

"Dad was extremely well-documented. After a debate at Chico State in the late 60s, we talked about having references at the ready to refute bad arguments. This led to a couple of very full boxes that traveled in the trunk of his car with copies of published works that backed up his positions. And that in addition to the famous stacks of re-prints in his home office."

Today the work of William Emery Hazeltine II lives on through the William Hazeltine Memorial Student Research Fellowship Awards. UC Davis students studying mosquitoes are eligible to apply for the award.

Recipients:

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

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--Kathy Keatley Garvey
Communications specialist
UC Davis Department of Entomology
(530) 754-6894