Home Breaking Study | Air pollution kills the love of insects

Study | Air pollution kills the love of insects


(Paris) Flies, in full sexual confusion, unable to distinguish males from females: air pollution, which already threatens the pollination of plants, is also wreaking havoc in the reproduction of certain insects, shows a study published Tuesday in Nature Communications .

At the origin of the phenomenon, ozone, one of the most common pollutants which, even at a moderate dose, has the effect of degrading the olfactory perceptions of insects. And it also affects pheromones, those fragrant chemicals that cause unconscious sexual or social reactions in an individual of the same species.

As a result, in experiments with typical big-city ozone levels on Drosophila, those little gnats that very often hover around fruit, males suddenly find themselves deprived of all sex appeal in the eyes of females, who don’t. are more likely to mate.

And some males, sexually in the fog, even find themselves chasing their congeners of the same sex, reducing to nothing any possibility of reproduction.

This disturbed sexual communication is mainly triggered by the oxidative effect of atmospheric pollution on the carbon chains of pheromones and lasts for several days.

This problem is found in nine of the ten species of Drosophila studied, but could also affect other insects whose behavior is also based on pheromones, underline the scientists.

This factor, hitherto unknown, could accentuate the decline that has affected nearly half of insect species in recent decades.

“We’re talking about millions of species,” Markus Knaden, one of the study’s contributors and member of the Max Planck Institute, told AFP, citing “moths, butterflies, ants , bees, wasps.

Prior to industrialization, natural ozone levels in the air averaged around 40 parts per billion (ppb) globally. But today, in cities and industrial areas, ozone levels can easily reach 210 ppb, or about five times that.

“Everything was fine, until we got there,” Mr. Knaden said. “It’s entirely our fault.”

The study showed that even short-term exposure to ozone levels of 100 ppb resulted in significant pheromone degradation. And the higher the concentration of ozone, the greater the impact. Not to mention the influence of other pollutants, such as nitrogen monoxide, which oxidize at even faster rates and could reinforce the phenomenon.

Experiments, led by scientists at the University of Reading in England, are underway to determine how other flying and crawling insects might be affected.