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

Abstract

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.

Aedes albopictuscolonies from different geographic origins differ in their sleep and activity levels but not in the time of peak activity

“…Mosquito activity was measured using activity monitors that consist of 32 openings, with three sets of infrared emitters and detectors per opening (Trikinetics LAM25, Waltham, MA, USA.). Each mosquito was placed into a clear cylindrical glass tube with mesh covering one end and a custom-made cotton plug with access to 10% sucrose solution on the other end (See (Eilerts et al 2018, Upshur et al 2019, Ajayi et al 2022) for details). These tubes were then placed into the openings of the monitor so that the infrared beams bisected each tube in the middle.…”

Intra-species quantification reveals differences in activity and sleep levels in the yellow fever mosquito,Aedes aegypti

“…The activity and sleep profiles and levels of the multiple lines of Ae. aegypti were quantified using a Locomotor Activity Monitor 25 (LAM25) system developed for Drosophila (TriKinetics Inc., Waltham, MA, USA) and adapted for mosquitoes and ticks (Rund et al, 2012;Lima-Camara et al, 2014;Rosendale et al, 2019;Ajayi et al, 2022;Benoit et al, 2023). For each line, individual mosquitoes were loaded into 25×150 mm clear glass tubes with access to water and 10% sucrose provided ad libitum.…”

A two-process model ofDrosophilasleep reveals an inter-dependence between circadian clock speed and the rate of sleep pressure decay

“…A majority of this data set was curated from a review by Campbell and Tobler (1984) [1]. The remaining data were collected by a separate literature survey [66][67][68][69][70][71][72][73][74]. In all, we compared fly sleep to sleep in 187 species/populations (which includes Drosophila species from different geographical locations, other non-Drosophila invertebrates, non-mammalian vertebrates and mammals).…”

“…The copyright holder for this preprint this version posted August 15, 2022. ; https://doi.org/10.1101/2022.08.12.503775 doi: bioRxiv preprint Percentage of time spent sleeping for other species were computed based on the number of hours of sleep reported in Campbell and Tobler (1984) [1]. In addition, sleep amounts were estimated from published figures for a few other species whose sleep has been more recently quantified [66][67][68][69][70][71]. In all these cases the averaged/reported amount of sleep is multiplied by 100 24 .…”

“…Animals are arranged in descending order of % time spent sleeping. Data were compiled from the following sources:[1,[66][67][68][69][70][71][72][73][74].…”