In a recent study published by the scientific journal Current Biology, researchers Floris van Breugel and S. David Stupski from the University of Nevada, Reno, have tackled the age-old question of why flies buzz around in circles when the air is still. This research has practical implications as it could help in training robotic systems to track chemical leaks more effectively. Currently, there are no robotic systems that can efficiently track odor or chemical plumes, but insects, like flies, are adept at this task. By understanding how flies navigate chemical plumes, researchers hope to train drones to perform similar tasks.
The researchers used a new approach called optogenetics to remotely control neurons, specifically the “smell” neurons, on the antennae of flying fruit flies. This allowed the researchers to give flies identical virtual smell experiences in different wind conditions, which helped them understand how flies track odors when there is no wind to carry them. The study revealed that flies use environmental cues to detect and respond to air currents and wind direction to find their food sources. In the absence of wind, flies exhibit a behavior called sink and circle, which involves lowering altitude and making repetitive turns in a consistent direction.
Flies employ a cast and surge behavior in the presence of wind, where they surge into the wind after encountering a chemical plume and then cast side to side when they lose the scent. While this behavior has been previously understood, the sink and circle behavior observed in still air was previously unknown. This innate movement involves lowering altitude and making repetitive turns in a consistent direction. The researchers found that flies exhibit this behavior consistently and repetitively, indicating that they are able to assess the conditions of the wind before deploying a suitable strategy to navigate towards a food source.
This discovery is significant as it shows that flies are able to assess wind conditions and respond in a context-appropriate manner, rather than simply reacting to an odor with a preprogrammed response. This knowledge could be applied to train more sophisticated algorithms for scent-detecting drones to locate the source of chemical leaks. By understanding how flies navigate in search of food sources, researchers hope to develop more efficient methods for training drones to track chemical plumes and locate the source of leaks in various environments.
Overall, the research by van Breugel and Stupski sheds light on the intricate behaviors exhibited by flies in search of food sources. By uncovering the sink and circle behavior displayed by flies in still air, the researchers have provided valuable insights that could have implications for the development of robotic systems for tracking chemical leaks. This study highlights the remarkable abilities of insects to navigate their surroundings and adapt their behaviors based on environmental cues, which could be valuable in training drones for similar tasks in the future.
