“Pyrethroid resistance in Culex tarsalis

Sumiko De La Vega, MS

San Joaquin County Mosquito and Vector Control District Assistant Entomologist Sumiko De La Vega completed both her Master of Science and Bachelor of Science in biological sciences at the University of the Pacific (UOP). She was a graduate student in the Thiemann Lab at UOP and her research focused on insecticide resistance and identifying resistance mechanisms in populations of Culex tarsalis, a vector of West Nile virus.

  1. Pyrethroid resistance in Culex tarsalis in Northern California. Thiemann TC, De La Vega S, Ryan B. Proceedings and Papers of the Mosquito and Vector Control Association 89: 88.
  2. Insecticide resistance and the identification of resistance mechanisms in populations of Culex tarsalis from San Joaquin County, California. De La Vega SR, Huang S, Ryan B, Lucchesi E, Thiemann T. Proceedings and Papers of the Mosquito and Vector Control Association 88: 93-94.
  3. Pyrethroid resistance in Culex tarsalis. De La Vega S, Ryan B, Thiemann T. Proceedings and Papers of the Mosquito and Vector Control Association 87: 33.
  4. Determining pyrethroid resistance and resistance mechanisms in Northern California populations of Culex tarsalis. De La Vega S, Huang S, Ryan B, Thiemann T. Proceedings and Papers of the Mosquito and Vector Control Association 87: 156.

"The PacVec training grant allowed me to collaborate on a project between several mosquito control districts in Northern California to study pyrethroid resistance in Culex tarsalis and enzymatic and kdr target-site resistance mechanisms. Through this project, I developed new skills in molecular techniques and project management that I can apply to future work in vector control. The results of this research can also help guide vector control districts in their decisions involving insecticide use and resistance management."

Tara Thiemann, PhD, MS

Associate Professor, University of the Pacific


Dr. Tara Thiemann is an associate professor in the Biological Sciences Center at the University of the Pacific. Her research focuses on the biology of arthropod vectors (e.g. mosquitoes, ticks and fleas) that transmit pathogens to humans and other animals. The Thiemann Lab is currently focused on the mosquito vectors of West Nile virus, dog heartworm and other vector-borne pathogens found in California. They combine field techniques with molecular tools in the laboratory to better understand the ecology and behavior of the mosquitoes and determine how their unique biology relates to disease transmission.

“Assessment of risk and transmission cycle of the emerging tick-borne pathogen, Borrelia miyamotoi

Samantha Sambado, MS

Samantha Sambado is currently pursuing an ecology, evolution, and marine biology PhD at UC Santa Barbara with Dr. Cherie Briggs and Dr. Andy MacDonald to better understand how vector-borne diseases spread using empirical and theoretical frameworks. She completed her Master of Arts in probability and applied statistics with a concentration on data science in 2023 and completed her Master of Science in microbiology in 2019. She hopes to stay connected with other PacVec researchers to continue collaboration on vector-borne disease projects and exchange ideas of how to make basic science applicable to public health.

  1. Macro-parasites and micro-parasites co-exist in rodent communities but are associated with different community-level parameters. Saloman J, Sambado SB, Crews A, Sidhu S, Seredian E, Almarinez A, Swei A et al.  International Journal for Parasitology: Parasites and Wildlife. 2023.
  2. Linking Lyme disease ecology and epidemiology: reservoir host identity, not richness, determines tick infection and human disease in California. MacDonald AJ, McComb S, Sambado S. Environ. Res. Lett. 2022.
  3. Detection and isolation of Rickettsia tillamookensis (Rickettsiales: Rickettsiaceae) from Ixodes pacificus (Acari: Ixodidae) from multiple regions of California. Paddock CD, Swei A, Trent E, Zhong J, Sambado S, Foley J et al. Journal of Medical Entomology. 2022.
  4. Mixed transmission modes promote persistence of an emerging tick-borne pathogen. Sambado S, Saloman J, Crews A, Swei A. Disease Ecology. 2020 Jun 21.

"PacVec gave me the opportunity to conduct scientific research that became the foundation of my master’s thesis project. With PacVec's support, I was able to present the results from this project at 4 conferences, 3 invited talks, and submitted a peer reviewed paper. The exposure resulting from these presentations allowed me to connect with scientists from a variety of academic and government groups, which has directly improved my professional growth – including how I met my current Ph.D. advisor!"

Andrea Swei, PhD

Associate Professor, San Francisco State University


Dr. Andrea Swei is an associate professor in the Department of Biology at San Francisco State University. Research in the Swei Lab employs interdisciplinary approaches to understand the factors that determine the distribution and prevalence of Lyme disease and other tick-borne diseases. Dr. Swei’s research focuses on several different tick-borne disease systems such as Lyme disease, babesiosis, and Borrelia miyamotoi and employs ecological theory to examine the role of disturbance, habitat fragmentation, and biodiversity on tick-borne disease ecology and public health risk.

“Engaging community health workers for vector control and surveillance”

Joshua Arnbrister, BS

Joshua Arnbrister is currently pursuing a Master of Science in entomology at the University of Arizona and he plans to continue in a PhD program. After completing his PhD, he hopes to pursue a career in vector control and surveillance.

"The PacVec grant allowed me to pursue my thesis research, which was a project focusing on engaging community health workers in mosquito larval surveillance in Southern Arizona and the Arizona-Sonora Border region."

Kacey Ernst, PhD, MPH

Professor and Department Chair of Epidemiology and Biostatistics, University of Arizona


Dr. Kacey Ernst is a professor and Department Chair of Epidemiology and Biostatistics Department. Research in the Ernst Lab focuses on identifying how ecological and social changes impact the transmission of infectious diseases. Their aim is to incorporate that knowledge into the design of sustainable community-driven prevention and control strategies.

“Genomic basis of mammal-biting in Culex pipiens, a primary vector of WNV”

Yuki Haba, MA

Yuki Haba is a current PhD candidate at Princeton University, interested in the genomics and neurobiology of behavioral evolution. He is currently working with Dr. Lindy McBride on the behavioral evolution of Culex mosquitoes. Yuki completed his Master of Arts in ecology and evolutionary biology/genomics at Columbia University.

Auston Marmaduke Kilpatrick, PhD, MS

Professor, University of California, Santa Cruz


Dr. A. Marm Kilpatrick is a professor in the Ecology and Evolutionary Biology Department at the University of California, Santa Cruz. His research unites theory and empirical work to address basic and applied questions on the ecology of infectious diseases as well as population biology, evolution, climate, behavior, genetics, and conservation.

“Circulation of St. Louis encephalitis virus in the Southwestern United States”

Chase Ridenour

Chase Ridenour is a PhD candidate in bioinformatics at Northern Arizona University’s School of Informatics, Computing and Cyber Systems. After graduation he plans to obtain a postdoctoral position to continue his work developing phylogenetic and statistical models of vector-borne diseases.

  1. St. Louis encephalitis virus in the Southwestern United States: A phylogeographic case for a multi-variant introduction event. Ridenour CL, Roe CC, Henke JA, Raman V, Foster JT, Hepp CM et al. Front Genet. 2021.

Crystal Hepp, PhD

Associate Professor, Translational Genomics Research Institute


Dr. Crystal Hepp is an associate professor in the Pathogen and Microbiome Division of the Translational Genomics Research Institute. Dr. Hepp has a background in evolutionary biology and genomics, and her lab focuses heavily on using environmental surveillance of pathogens, especially viruses, to understand their spread over time and space.

“Is adaptation mal-adaptation: an assessment of mosquitoes and water harvesting”

Valerie Madera Garcia, MPH

Valerie Madera Garcia is currently pursuing a PhD in epidemiology with a minor concentration in entomology and insect sciences at the University of Arizona. Valerie's mission is to empower communities to develop sustainable and affordable vector control strategies to reduce the burden of painful and sometimes deathly mosquito-borne diseases around the world. She aspires to work for the Centers for Disease Control and Prevention as an infectious diseases and environmental epidemiologist. She also wants to contribute to the advancement of the field of mosquito-borne diseases and ensure the safety of at-risk and underrepresented populations from infectious diseases transmitted by mosquitoes.

"The PacVec training grant allowed me to attend school and gain knowledge and skills in the field of mosquito ecology and mosquito-borne diseases. It also catapulted my research interest in developing innovative vector control strategies that will help in the mitigation of arboviruses transmission around the world."

Heidi Brown, PhD, MPH

Associate Professor, University of Arizona


Dr. Heidi Brown is an associate professor at the University of Arizona. Dr. Brown’s PEST Lab, works to understand drivers behind the spatial and temporal distribution of infectious disease with a specific focus on vector-borne and zoonotic diseases. Models of vector, host and pathogen distributions and how they are influenced by environmental factors is used to map human disease risk. Current research diseases and tools include: West Nile virus, dengue, valley fever (coccidioidomycosis), spatial epidemiology, and climate change and health.

“Genetic variation and endosymbiont diversity of Rhipicephalus sanguineus populations across Arizona”

Maureen Brophy

  1. Genetic variation in Rhipicephalus sanguineus s.l. ticks across Arizona. Brophy M, Riehle MA, Mastrud N, Ravenscraft A, Adamson JE, Walker KR. Int J Environ Res Public Health. 2022.
  2. BiTeRS: Rickettsial surveillance at the US-Mexico border to save lives, engage new partners, and expand awareness of tick-borne disease. Foley J, Backus L, Lopez-Perez A, Walker K, Brophy M, Barker CM. Proceedings and Papers of the Mosquito and Vector Control Association 90: 81.

Kathleen Walker, PhD

Associate Professor, University of Arizona
Associate Specialist, Insect Discovery Outreach Program


Dr. Kathleen Walker is an associate professor in the Department of Entomology at the University of Arizona and an associate specialist directing the Insect Discovery Outreach Program, providing a variety of resources to help teachers make the most of their students’ fascination with the amazing world of insects. The Walker Lab studies the ecology of arthropod vectors that inhabit the peri-domestic environment, focusing on the influence of climate and human behavior on vectorial capacity. The Walker Lab has focused on Aedes aegypti on the U.S./Mexico border, investigating the interactions between climates, mosquito longevity and dengue transmission. They are now broadening their focus to examine the ecology of Rhipicephalus sanguineus, the brown dog tick, and factors driving regional rickettsia outbreaks.


PacVec’s training grant program intends to provide career development opportunities for individuals interested in public-health-relevant research on vector-borne diseases and to enable additional research and training opportunities that will contribute to the development of the public health workforce.

The Pacific Southwest Regional Center of Excellence in Vector-Borne Diseases is supported through Cooperative Agreement Number 1U01CK000649 between the Centers for Disease Control and Prevention (CDC) and the University of California, Davis.

© 2024 – All rights reserved