New NSF-funded research explores origins of blood feeding in mosquitoes

An interdisciplinary team of Virginia Tech researchers is seeking to understand the physiological and biomechanical characteristics of blood feeding in mosquitoes and their evolutionary transition from sugar to blood feeding — knowledge that may help future work to stop disease transmission.

“Mosquitoes are the deadliest animals on the planet due to the pathogens they transmit to humans and other animals,” said Chloé Lahondère, an assistant professor of biochemistry in the College of Agriculture and Life Sciences and an affiliate faculty member of the Center for Emerging, Zoonotic, and Arthropod-borne Pathogens in the Fralin Life Sciences Institute.

“Female mosquitoes transmit pathogens while biting a host,” she continued. "Females can also feed on plants, so food sources include blood, nectar, and plant fluids, which differ widely in viscosity and temperature. One of the key objectives of our project is to understand the specific adaptations that allow certain species of female mosquitoes to feed on such a wide range of fluids.”

Lahondère and Clément Vinauger, also an assistant professor in biochemistry in the College of Agriculture and Life Sciences and an affiliate faculty of the Center for Emerging, Zoonotic, and Arthropod-borne Pathogens, will work with Jake Socha, the Samuel Herrick Professor in biomedical engineering and mechanics, and Mark Stremler, professor in biomedical engineering and mechanics in the College of Engineering, to analyze the biomechanical constraints and trade-offs between sugar and blood feeding in mosquitoes, thanks to a $1 million grant from the National Science Foundation.

While much is known about mosquito feeding, such as some species’ ability to feed on a wide range of hosts, from mammals to amphibians, how this ability evolved and the effects thereof remain unknown.

Male and female mosquitoes use sugar to feed their metabolism and sustain life. Males feed solely on nectar throughout their life, while females also feed on vertebrate hosts  – such as humans – and use blood nutrients to produce eggs. Only adult females feed on blood, and this is true for only some species. This specialization of blood feeding depending on sex and species is unique and is the main topic of interest in the team’s research.

All members of the team have studied mosquitoes previously, but these insects form the basis of Lahondère’s and Vinauger’s research programs. In the Lahondère Lab, research is focused on blood-sucking insects’ thermal biology, physiology, and neuro-ethology. Neuro-ethology is the study of the neural basis of natural behavior in animals, looking at how sensory organs and central structures behaviorally process stimuli and how this is integrated by the central nervous system. The Vinauger Lab relies on an integrative, collaborative approach in studying the molecular, physiological, and neural basis of mosquito behavior.

The other half of the research team will bring an engineering element to the physiological basis of the project.

Socha’s research aims to uncover fundamental principles of how animals function from a mechanical perspective and apply those principles to new engineering design. Stremler’s research focuses on fluid mechanics and dynamical systems theory. Stremler applies mathematical and computational models to understanding the dynamics and control of fluid systems.

Transcending discipline boundaries enables all four researchers to use complementary experimental and computational methods to determine both the physiology and the biomechanics of mosquitoes’ blood versus sugar feeding. They also aim to identify underlying differences in fluid ingestion in mosquitoes, knowing the insects ingest fluids that differ widely in both temperature — such as those of cold-blooded amphibians and warm-blooded humans — and viscosity.

Determining what physiological and biomechanical characteristics allow mosquitoes to feed on blood is critical to understanding what makes a mosquito susceptible to transitioning to blood feeding. Identifying these factors could also reveal potential targets for the control of mosquito-borne diseases — by making mosquitoes unable to feed on blood, for example, said Lahondère, who is also an affiliate member of Fralin Life Science Institute's Global Change Center. 

“The data and insights gained from this project are expected to expand our knowledge in the fields of disease vector biology and biomechanics,” said Vinauger. “Such knowledge will help us better design industrial biomedical tools. It may also reveal ways to disrupt mosquitoes’ ability to feed on blood and thereby transmit diseases.”

“We expect our discoveries to have real-life applications in industry and other settings,” said Stremler. “For applications that require flow in very small channels, the mosquitoes should provide inspiration for ways to produce and control the flow using microscale pumps.”

Their research aims to advance knowledge of mosquito feeding, while also pursuing educational opportunities.

“Mosquitoes are often seen only as disease vectors at worst, or an annoyance at best,” said Socha. “We plan to reach out through multiple initiatives, including BugFest and Kids’ Tech University, to teach kids about mosquitoes’ roles in the ecosystem.”

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