Mosquito populations are increasing in the United States, raising concerns about diseases such as West Nile virus. Assistant Professor Kelsey Lyberger and her team at Arizona State University are researching local mosquito behavior to better understand how these insects impact public health.
“West Nile virus spreads to humans when mosquitoes bite infected migratory birds and then bite people,” Lyberger said. “The mosquito landscape has changed. They have increased in abundance, and we can attribute this to warmer climates and weather events like Arizona monsoons.”
Lyberger’s team is focusing on Culex mosquitoes, a common carrier of West Nile virus in the U.S., to determine where and when they thrive. Their research involves collecting temperature data from 24 different microhabitats across Phoenix, including plant nurseries and park drains, to see how mosquitoes survive extreme heat.
“We collect mosquito larvae in the field and rear them in the lab until they are adults,” said Chloe Martz, a fourth-year student working with Lyberger. “We identify the species to determine their critical thermal maximum and compare the temperatures we recorded at each site to figure out how often each site gets above the mosquitoes’ thermal maximum, and compare this to the city’s weather station data.”
The team found that temperatures at their study sites were generally cooler than those reported by city weather stations, which may explain why mosquitoes continue to thrive despite high average temperatures.
Even so, Lyberger noted, “These hearty little creatures are living on the edge of their critical thermal maxima,” referring to the highest temperature mosquito larvae can withstand.
“They can either adapt through acclimation, where physiologically they can prepare for hot temperatures, or evolutionarily, meaning different mosquito populations are more adapted to the heat,” Lyberger explained.
The researchers plan to use mathematical modeling combined with their temperature data to predict when mosquito activity will be highest. Their goal is to provide information that helps Maricopa County Vector Control target efforts such as fogging more effectively.
“We hope to use our findings to inform Maricopa County Vector Control and public health agencies of where and when transmission will occur, so they can be more targeted in mitigating populations with fogging and other methods,” Lyberger said. “Maricopa County Vector Control has a rich dataset of mosquito abundance, so I’m also using statistical approaches to learn how effective their treatment has been.”
Martz described how participating in this research project has helped her develop skills important for her future career: “The hands-on work is engaging. I get to go out into the field to identify plants and animals. It’s what future employers want to see on my resume, and it makes the classes interesting,” she said. “When I get back to the lab to process the data, I get to see the results of what I’ve been working so hard to achieve. It’s those ‘aha’ moments that are so rewarding.”
Lyberger added that students in applied biological sciences have many career options across fields such as environmental science, epidemiology, public health, data science and academia.
Looking ahead, Lyberger plans further research into mapping U.S. mosquito invasion fronts related to dengue fever as temperatures rise. She also intends to study how short- and long-term weather disturbances affect mosquito survival and disease transmission.
Arizona State University continues its commitment toward innovation through projects like this one; it was recently named number one in innovation for eight consecutive years by U.S. News & World Report (https://news.asu.edu/20220911-university-news-asu-no-1-innovation-us-news-world-report-eighth-year?utm_source=twitter&utm_medium=asu&utm_campaign=ASURankings&utm_term=USNWR).
Additionally, ASU collaborates with partners such as Argos Vision—a tech startup developing smart traffic cameras—on initiatives throughout Phoenix (https://www.phoenix.gov/newsroom/street-transportation/2420).
Lyberger says she looks forward to involving more students in future projects aimed at understanding how organisms adapt—and inspiring new scientific discoveries.
