Phytophagy (i.e., feeding on plant-derived materials) is an essential component of mosquito biology. Yet, it has been historically neglected as most research effort has been concentrated on host-seeking behavior and pathogen transmission. As mosquitoes are the deadliest animals on earth and because challenges, such as the rise of insecticide resistance, arise, there is an urgent need for developing effective and ecologically friendly disease vector control strategies. It is therefore important to deepen our understanding of mosquito phytophagy and, consequently, its potential to develop novel vector control methods. Particular major disease vectors are Ae. aegypti and Ae. albopictus, which are spreading rapidly through the US, in part due to climate change. Herein, we first examine the effect of temperature on Ae. aegypti sugar-feeding behavior as well as overall locomotive activity and survival, using total carbohydrate assays and actometer experiments. An optimum temperature range for mosquito activity is proposed and discussed in the context of global warming. We then observe the tentative benefit provided by city-planted ornamental flowers to Ae. aegypti and Ae. albopictus living in heavily-populated, urban areas. Mosquito sugar-feeding activity and, subsequently, sugar consumption were tested for eleven commonly-planted ornamentals. Additionally, scents were collected from the headspace of each ornamental, and volatile composition was analyzed and discussed as potential cues that could mediate mosquito-plant interactions.

Sugar-feeding is an important, but generally neglected, aspect of mosquito biology, affecting, for example, their survival, metabolism, and ability to lay eggs. While females need blood to mature their eggs, males feed exclusively on sugar, further highlighting the importance of this food source. Mosquitoes use several cues to locate flowers to feed on, including the plant scent. Aedes aegypti and Aedes albopictus are two urban species that are invasive to the US and are the vectors of several deadly pathogens including dengue, Zika and chikungunya. It is thus to study any aspect of their biology that could lead to the development of new tools to limit their propagation. Because of the nutrients provided to mosquitoes by flowering plant species, considering the dynamic ecological relationship between human, plant, and mosquito in urban, heavily populated areas is critical. Additionally, how temperature is mediating each of these interactions is important to understand and keep in consideration. Here, we first examine the effect of temperature on sugar-feeding, activity and survival in Ae. aegypti, and discuss our results in the context of potential changes in temperature caused by climate change. We also provide some insights on the role that ornamental flower species play in urban areas in the ability of these mosquito species to thrive, by attracting mosquitoes to areas where they will have access to a high number of human blood meals.

Master of Science in Life Sciences