State-dependent domicile leaving rates in Anopheles gambiae

Malaria Journal. 2018;17(1):1-8 DOI 10.1186/s12936-017-2166-4

 

Journal Homepage

Journal Title: Malaria Journal

ISSN: 1475-2875 (Online)

Publisher: BMC

LCC Subject Category: Medicine: Internal medicine: Special situations and conditions: Arctic medicine. Tropical medicine | Medicine: Internal medicine: Infectious and parasitic diseases

Country of publisher: United Kingdom

Language of fulltext: English

Full-text formats available: PDF, HTML

 

AUTHORS


Simon P. W. Zappia (Evolutionary and Behavioural Ecology Research Group, Department of Biological Sciences, Simon Fraser University)

Alex M. Chubaty (Evolutionary and Behavioural Ecology Research Group, Department of Biological Sciences, Simon Fraser University)

Bernard D. Roitberg (Evolutionary and Behavioural Ecology Research Group, Department of Biological Sciences, Simon Fraser University)

EDITORIAL INFORMATION

Blind peer review

Editorial Board

Instructions for authors

Time From Submission to Publication: 13 weeks

 

Abstract | Full Text

Abstract Background Transmission of Plasmodium greatly depends on the foraging behaviour of its mosquito vector (Anopheles spp.). The accessibility of blood hosts and availability of plant sugar (i.e., nectar) sources, together with mosquito energy state, have been shown to modulate blood feeding (and thus biting rates) of anopheline mosquitoes. In this study, the influence of mosquito starvation status and availability of nectar on the decision of female Anopheles gambiae mosquitoes to leave a bed net-protected blood host was examined. Methods Two small-scale mesocosm experiments were conducted using female mosquitoes starved for 0, 24 or 48 h, that were released inside a specially constructed hut with mesh-sealed exits and containing a bed net-protected human volunteer. Floral cues were positioned on one side of the hut or the other. Several biologically plausible exponential decay models were developed that characterized the emigration rates of mosquitoes from the huts. These varied from simple random loss to leaving rates dependent upon energy state and time. These model fits were evaluated by examining their fitted parameter estimates and comparing Akaike information criterion. Results Starved mosquitoes left domiciles at a higher rate than recently fed individuals however, there was no difference between 1- and 2-day-starved mosquitoes. There was also no effect of floral cue placement. The best fitting emigration model was one based on both mosquito energy state and time whereas the worst fitting model was one based on the assumption of constant leaving rates, independent of time and energy state. Conclusions The results confirm that mosquito-leaving behaviour is energy-state dependent, and provide some of the first evidence of state-dependent domicile emigration in An. gambiae, which may play a role in malarial transmission dynamics. Employment of simple, first-principle, mechanistic models can be very useful to our understanding of why and how mosquitoes leave domiciles.