Flies smell the motion of odors and use it to navigate

Amazing stuff! Chasing turbulent odors!

"... They found that the fly antennae worked in tandem to recognize the direction that odor packets were moving, allowing flies to adjust course based on signals from odor packets alone.  ...
This knowledge will not only aid agriculture (how bees find flowers) and public health (how mosquitoes find people), but also the development of robots that can sense dangers in the environment (where landmines are buried) ..."

From the abstract:

"Odour plumes in the wild are spatially complex and rapidly fluctuating structures carried by turbulent airflows. To successfully navigate plumes in search of food and mates, insects must extract and integrate multiple features of the odour signal, including odour identity, intensity and timing. Effective navigation requires balancing these multiple streams of olfactory information and integrating them with other sensory inputs, including mechanosensory and visual cues. Studies dating back a century have indicated that, of these many sensory inputs, the wind provides the main directional cue in turbulent plumes, leading to the longstanding model of insect odour navigation as odour-elicited upwind motion. Here we show that Drosophila melanogaster shape their navigational decisions using an additional directional cue—the direction of motion of odours—which they detect using temporal correlations in the odour signal between their two antennae. Using a high-resolution virtual-reality paradigm to deliver spatiotemporally complex fictive odours to freely walking flies, we demonstrate that such odour-direction sensing involves algorithms analogous to those in visual-direction sensing. Combining simulations, theory and experiments, we show that odour motion contains valuable directional information that is absent from the airflow alone, and that both Drosophila and virtual agents are aided by that information in navigating naturalistic plumes. The generality of our findings suggests that odour-direction sensing may exist throughout the animal kingdom and could improve olfactory robot navigation in uncertain environments."

Flies smell the motion of odors and use it to navigate, Yale study finds | YaleNews A team of Yale scientists, using genetically modified fly antennae to detect light, show flies can detect the motion of odor packets, independent of the wind.

Odor motion sensing enables complex plume navigation (preprint)

Odour motion sensing enhances navigation of complex plumes  (open access)