Celestial Navigation in Drosophila
Insects exhibit impressive navigational abilities, from long distance migrations of monarch butterflies to path integration of desert ants in the genus Cataglyphis. Celestial cues — including polarized light and solar position — provide valuable information to navigating insects, and the brain regions that process this information appear largely conserved. Although not generally considered migratory, mark-recapture experiments indicate that Drosophila can cover 10 km of open desert in perhaps as little as a few hours without stopping to refuel. This impressive feat required flies to adopt a fairly straight path, likely accomplished by visually-guided navigation using celestial cues. Like many insects Drosophila possess the ability to navigate using the polarization pattern of skylight but sun-compass navigation in this genus has not been examined. Using a flight simulator with machine-vision wing tracking, we found that tethered D. melanogaster can use the position of a simulated sun to fly straight, and individuals vary in their heading preference. This preferred heading is maintained over short intervals, but fidelity decays as the time between flights is increased. By training flies with a stimulus restricted to one half of the arena, we could bias subsequent headings towards the side of the training stimulus. These findings suggest that flight and/or visual experience can influence heading, although the neural basis remains unknown. Drosophila sun compass navigation has the potential for future behavioral, ecological and neurobiological studies that could shed light on the deep evolutionary roots of visually-guided locomotion.
© 2017 Oxford University Press.