Scent on the wing: exploring flight effects on insect odor detection

If it seems like fruit flies always manage to sniff out your snacks, it is likely because flies have finely honed olfactory systems that enable them to detect food, escape from predators, and find mates. Instead of noses, insects use their antennae to sense odors and navigate to – or away from – the smelly source.

Using experimental data, Lei and Li simulated the aerodynamics of insect flight, and how the flapping of fruit fly wings influences odor detection. Their work lends insight into insect behavior and could provide the basis for bio-inspired robotics.

“Our simulation is a sophisticated computer model that mimics the flight of a fruit fly as it moves through the air and detects scents,” said author Chengyu Li. “We can see not only how the fly flaps its wings, but also how these wing movements affect the flow of air and the spread of scent particles.”

A fly’s flapping wings enable propulsion and aid odor detection. When the wing beats, the resulting airflow patterns transport odor particles for efficient identification.

“At slower wing-beat frequencies, the fly disturbs the scent trail, making it harder to follow, while faster wing-beat frequencies create a special point in the airflow that can reduce the fly’s scent detection but increase the area over which it can detect odors,” said Li. “When the fly moves through the air more quickly, it actually smells better because the odor particles spread more effectively and are caught more efficiently by the flow created by the wings.”

The authors envision autonomous robots employing an insect-inspired technique to detect scents for searching large areas or finding chemical leaks.

Source: “Wings and whiffs: Understanding the role of aerodynamics in odor-guided flapping flight,” by Menglong Lei and Chengyu Li, Physics of Fluids (2023). The article can be accessed at https://doi.org/10.1063/5.0174377 .