By Stephen Beech via SWNS
The humble housefly could be key to developing robots able to sniff out chemical leaks, according to new research.
The reason the pests buzz around in circles when the air is still may help better train robotic safety systems, say American scientists.
Assistant Professor Floris van Breugel and Dr. David Stupski, of the University of Nevada, have been considering the previously unanswered question.
Dr. van Breugel said: “We don’t currently have robotic systems to track odor or chemical plumes.
“We don’t know how to efficiently find the source of a wind-borne chemical.
“But insects are remarkably good at tracking chemical plumes, and if we really understood how they do it, maybe we could train inexpensive drones to use a similar process to find the source of chemicals and chemical leaks.”
He explained that a fundamental challenge in understanding how insects track chemical plumes is that wind and odors can’t be independently manipulated.
To address the challenge, the researchers used a new approach that makes it possible to remotely control the “smell” neurons on the antennae of flying fruit flies by genetically introducing light-sensitive proteins, an approach called optogenetics.
The experiments made it possible to give flies identical virtual smell experiences in different wind conditions.
The researchers wanted to know how flies find an odor when there’s no wind to carry it.
Dr. van Breugel explained that flies use environmental cues to detect and respond to air currents and wind direction to find their food sources.
He says that, in the presence of wind, those cues trigger an automatic “cast and surge” behavior, in which the fly surges into the wind after encountering a chemical plume, indicating food, and then casts – moves side to side – when it loses the scent.
Cast-and-surge behavior has been understood by scientists for some time, but Dr van Breugel said it was “fundamentally unknown” how insects searched for a scent in still air.
In their work, published online by the journal Current Biology, the research team uncovered another automatic behavior – “sink and circle” – which involves lowering altitude and repetitive, rapid turns in a consistent direction.
They say flies perform the movement consistently and repetitively, even more so than cast-and-surge behavior.
Dr. van Breugel says the most exciting aspect of the discovery is that it shows flying flies are clearly able to assess the conditions of the wind – its presence, and direction -before deploying a strategy that works well under those conditions.
He added: “The fact that they can do this is actually quite surprising -can you tell if there is a gentle breeze if you stick your head out of the window of a moving car?
“Flies aren’t just reacting to an odor with the same pre-programmed response every time like a simple robot, they are responding in a context-appropriate manner.
“This knowledge potentially could be applied to train more sophisticated algorithms for scent-detecting drones to find the source of chemical leaks.”
