Turbulent Olfactory Navigation

Casting behavior is highly stereotyped in flying moths but temporally variable in flying Drosophila and walking cockroaches. Turbulent odor plumes are highly intermittent, with molecules arriving in sparse, unpredictable filaments rather than smooth gradients. After detecting an odor cue, insects typically surge upwind, then cast laterally, and finally return downwind if the plume is lost. Experimental evidence from walking Drosophila indicates that time elapsed since the last odor detection is a primary driver of navigation behavior.