Abstract:

Male mosquitoes of haematophagous species are obligate host-plant feeders, but female mosquitoes also depend on sugary plant-derived food sources for building energy reserves and enhanced reproductive success. The significant differences between the two sexes in host-plant feeding behaviours are accompanied by sexual dimorphism in the structure and function of digestive organs, as well as in metabolic pathway regulation for utilisation of a sugar-rich diet in males, and sequential sugar-rich and blood meals in females. Host-plant food sources of mosquitoes include nectar from inflorescences and extrafloral nectaries, sap, fluid from seed pods and fruit, as well as excreta from insects that feed on plant sap. While mosquitoes use olfactory cues to find host plants, the taste system is engaged upon contact, and is involved in assessing the suitability of a meal for ingestion. Host-plant-derived food sources are rich in sugars, and also contain nutrients such as amino acids, vitamins and minerals, as well as phytochemicals that may influence memory and feeding preference. Taste responses to some of these nectar components have been identified in the mosquito labellum and tarsi, but in most cases only few sensilla have been evaluated with a few tastants. The field is primed for more in-depth investigations of taste coding in mosquitoes. While a lot can be inferred from studies in Drosophila, there exist gaps in our understanding of the molecular basis of taste detection in mosquitoes. In this chapter, we present an overview of our current understanding of host-plant feeding and the taste sensory functions that underlie it. Further investigation of mosquito taste, behaviour, and evolution may lead to new targets and strategies for mosquito control.