The way in which male moths locate females flying hundreds of meters away has long been a mystery to scientists. Researchers know the moths use pheromones to locate their mates. Yet when these chemical odors are widely dispersed in a windy, turbulent atmosphere, the insects still manage to fly in the right direction over hundreds of meters with only random puffs of their mates' pheromones spaced tens of seconds apart to guide them.

"The male moths are flying toward females integrating all of this information along the way and somehow getting to them," said Massimo Vergassola, a professor of physics at UC San Diego. "French naturalists reported this behavior over a century ago and it has continued to be a puzzle to entomologists, neuroscientists and physicists."

Vergassola and two other physicists from research institutes in France and Italy, however, now appear to have come up with a mathematical explanation for the moths' remarkable ability, which they describe in a paper published in the October issue of the journal Physical Review X titled "Odor Landscapes in Turbulent Environments."

The three physicists developed a statistical approach to trace the evolution of trajectories of fluid parcels in a turbulent airflow, which then allowed them to come up with a generalized solution to determine the signal that animals sense while searching for food, mates and other things necessary for survival.

"This a general problem -- how animals, including ourselves, search for things," said Vergassola, the senior author of the paper, which includes Antonio Celani of ICTP in Italy and Emmanuel Villermaux of Marseille University in France . "A similar problem exists for flies that can detect garbage cans far away or for dogs that are guided by scents, although the difference is that their smells are generally on the ground, so their signals are much more stable. Insects face the most difficult problem as they rely on olfaction and detecting the volatile signals dispersed in the wind. When the atmosphere is turbulent, the signal becomes sporadic and simply disappears for long periods of time."