Behavioral and postural analyses establish sleep-like states for mosquitoes that can impact host landing and blood feeding

Sleep is an evolutionarily conserved process that has been described in
different animal systems. For insects, sleep characterization has been
primarily achieved using behavioral and electrophysiological correlates in
a few systems. Sleep in mosquitoes, which are important vectors of
disease-causing pathogens, has not been directly examined. This is
surprising as circadian rhythms, which have been well studied in
mosquitoes, influence sleep in other systems. In this study, we
characterized sleep in mosquitoes using body posture analysis and
behavioral correlates and quantified the effect of sleep deprivation on
sleep rebound, host landing and blood-feeding propensity. Body and
appendage position metrics revealed a clear distinction between the
posture of mosquitoes in their putative sleep and awake states for
multiple species, which correlate with a reduction in responsiveness to
host cues. Sleep assessment informed by these posture analyses indicated
significantly more sleep during periods of low activity. Nighttime and
daytime sleep deprivation resulting from the delivery of vibration stimuli
induced sleep rebound in the subsequent phase in day and night active
mosquitoes, respectively. Lastly, sleep deprivation suppressed host
landing in both laboratory and field settings, and impaired blood-feeding
of a human host when mosquitoes would normally be active. These results
suggest that quantifiable sleep states occur in mosquitoes and highlight
the potential epidemiological importance of mosquito sleep.