Eco-epidemiological multi-scale approach
As a biologist, I am fascinated by individual differences in animal behavior, and particularly, I am intrigued by how selective forces acting on organisms drive inter-individual behavioral variations. Exploring this interest in the context of mosquito ecology, identifying the fine-scale mechanisms by which ecological drivers influence the behavior and life-history of mosquitoes and the diseases they vector form the crux of my research. My research is multidisciplinary encompassing approaches in field ecology, ethology, molecular and sensory physiology, and quantitative ecology, and is driven by collaborations with research groups in India and the United States.
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Our research focuses on how mosquitoes' interactions with the environment influence their behavior in epidemiologically relevant contexts. As larvae, mosquitoes occupy diverse habitats and are influenced by many ecological factors that impact their adult life. Interestingly, the magnitude of these effects differs between males and females, with the latter showing remarkable plasticity of body size in response to environmental variability. Also, body size in females strongly correlates with their adult behavior and reproductive traits. In this context, my experiments varied levels of intraspecific competition to quantify how larval conditions impact olfactory responses of adult females seeking hosts for blood. The results suggest that the onset of host-seeking preferences is strongly linked to variability in female body size. To identify the mechanistic aspects of the observed size-dependent variations in host-seeking, analysis of the head transcriptome of large and small-sized females reveals differences in the expression of genes involved in chemosensation and synthesis of targeted neurotransmitters. I am pursuing electrophysiological investigations from mosquitoes' antennae and antennal lobes of tethered-behaving preparations using these results. The results reveal the peripheral and central consequences of differential gene expressions for olfactory detection and processing in the context of host-seeking. In collaboration with Dr. Lauren Childs (Applied Mathematician at VT) and Dr. James Weger-Lucarelli (Virologist at VT), a manuscript summarizing these research findings in the context of mosquito population dynamics and the ensuing disease consequences using predictive models is currently in preparation. This research investigations fits within the eco-epidemiological multiscale conceptual framework that I have developed in collaboration with Dr. Luis Escobar and Dr. Chloé lahondère to link findings on mosquito ecology, life-history traits, and mosquito-borne diseases.
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Mosquito body size
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Larval ecology, mosquito life history
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We also study how non-lethal predation threat interacts with larval nutrition and conspecific larval density to affect life histories and mosquito abundances. During the development stages, mosquito larvae are influenced by several ecological factors, and these effects cascade to impact adult mosquitoes. While studies have investigated the effects of crucial ecological factors in isolation, their interactive effects are not well known. With the motivation of investigating these interactive effects, I quantified the long-term effects of non-lethal predation and other critical ecological variables on both simple (size at and time to maturity) and complex (body composition, adult longevity) life-history traits. I developed protocols to expose larval mosquitoes to predation threat, follow them individually through their life cycle to quantify multiple trait data, and assess stored energy reserves using biochemical analyses. Within the eco-epidemiological multi-scale framework, I will employ these protocols to investigate the influences of coarse-scale ecological interactions on the evolution of life histories in mosquitoes.
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We also investigate how non-lethal predation operates at a finer scale to influence the behavioral responses of mosquito larvae and pupae under different contexts. Studies on predator-prey interactions have examined varied aspects of non-lethal interactions both in natural and laboratory conditions, but certain avenues remain poorly understood. For instance, prey organisms integrate information from different sensory modalities (also called 'cues') to assess predation threat. However, relatively little is known about the importance of each of those cues, its role in signaling threat to prey, and how prey perceives threat from multiple predators. While it is intuitive that anti-predator behavior would reduce predation risk, details of such a risk reduction are hard to investigate. My research, under the mentorship of Dr. Kavita Isvaran, sought to test the assumption using simulations of digital larvae experimentally. These experiments provided the platform for several smaller research projects involving undergraduate and master's students.
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Threat-sensitive behavior in
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