PARIS - We all know air pollution is bad, but it is even worse for fruit flies.
Ozone-laden smog is playing havoc with their sex lives.
Not only does it cause male flies to lose their sex appeal, it also leaves them unable to tell the difference between he-flies and she-flies, according to German scientists.
While this is unfortunate -- tragic even -- for flies, it is also extremely worrying for the planet, said Markus Knaden of the Max Planck Institute for Chemical Ecology.
For it may be a driver in the accelerating decline of nearly half of all insect species.
"We're talking about millions of species," said Knaden, adding, "Things were great until we came along."
The radical changes in mating behaviour stem from a breakdown of the scent signals, or pheromones, used to attract sexual partners.
In experiments, the type of ozone emitted from vehicle tailpipes and factories neutralised pheromones after they were released, leading to mating mayhem.
The researchers said impacts are likely to be "even higher than we observed" in polluted cities because of the presence of other pollutants, such as nitric oxides, that oxidise at even faster rates.
Field experiments underway in England run by scientists at the University of Reading -- measuring the impact of diesel exhaust and ozone pollution on pheromones in a range of insects -- could confirm whether other flying and crawling bugs are similarly affected.
Social insects such as ants use the chemical cues to identify members of their colony.