Despite current control methods, mosquito-borne diseases continue to present themselves as a burden on public health and mosquitoes remain a continual nuisance. Maintenance of water homeostasis represents a critical component underlying mosquito survival and proliferation. Water availability is required for mosquitoes to complete their life cycle, as all stages of juvenile development occur in an aquatic environment. Adult mosquitoes must balance overhydration following the large volume of water ingested during blood feeding, with suppressing water loss between feeding, when death due to dehydration can occur within hours under warm and dry conditions. Considerable progress has been made in understanding water homeostasis and hygrosensation, but there are substantial gaps in the molecular and behavioural mechanisms of these processes that must be filled. This chapter focuses on summarising the relationship between mosquitoes and water, the putative genes involved in hygrosensation, and the physiology behind how mosquitoes use this relationship to survive. As pesticide resistance is an increasing concern in mosquito control, mechanisms that interfere with water homeostasis and hygrosensation could yield new avenues for mosquito population reduction, through increasing dehydration-induced mortality or developing water-based traps. These approaches could be used to break the cycle of mosquito-borne disease transmission by interfering with the necessary interactions of mosquitoes with water.
