Molecular Physiology of Mosquito Diapause

The dormant state of diapause is exploited by numerous mosquito species to survive seasonal periods of environmental stress. We discuss embryonic, larval and adult diapauses in mosquitoes and probe the molecular and physiological distinctions that comprise the diapause phenotype. Diapause evokes diverse and unique attributes including behavioural changes, arrested development, enhanced stress tolerance, fat accumulation and suppressed metabolic rates. Like most insects, mosquitoes in temperate latitudes precisely monitor daylength as a cue for diapause initiation. We examine the role of circadian clock genes in this response and trace downstream hormonal pathways involved in the diapause response. Insulin and the FOXO transcription factor signalling pathways appear to be keys for generating the diapause phenotype in adult females of Culex pipiens and perhaps other species. Elucidating the molecular regulation of diapause-associated physiology may provide a basis to identify novel targets for the control of mosquito vectors.