Ozone pollution disrupts the sexual life of insects

These are secreted by males in Drosophila species and increase their attractiveness in females. At the same time, males use scent to distinguish females from other males.

And while their pheromone attracts females, it repels other males. During mating, the males transfer their pheromone to the females. As a result, females that have just mated and smell like a pheromone are no longer attractive to other males for the next few hours.

Not only did increased levels of ozone make females less attractive to males, but “ozone-deficient” males suddenly also became more interesting to their male counterparts.

“We knew that elevated ozone levels could affect insect mating systems due to oxidative breakdown of the carbon-carbon double bond and thus pheromones, which is not rocket science. However, we were shocked that even slightly elevated ozone concentrations had such powerful effects on fly behavior. ”, according to Jiang and Kanadin.

“Originally, we wanted to focus mainly on the interactions between males and females. We can explain that males started courting each other even after a short exposure to ozone, because obviously they could no longer distinguish between ozonated males and we hadn’t thought of this before.” , so we were completely astounded by the behavior of the males exposed to ozone, forming long chains to align themselves with each other.”

As mentioned, the research team also looked at the effects of elevated ozone levels in the air on the mating behavior of eight others Drosophilaspecies, in addition to Drosophila melanogaster. In all eight species, the team observed unusual courtship behavior by males toward other males exposed to ozone.

Even the males of the species Bosque fruit fly It was less successful in mating after exposure to ozone, although as mentioned, ozone does not affect the pheromone secreted by males of this species. However, it is possible that other, yet to be identified, ozone-sensitive chemical compounds may play an additional role in mating behaviour.

Finally, the team also studied a type, Suzuki Drosophilawhich is known to not have pheromones but bases courtship on visual cues, and interestingly enough, those species were not affected at all by elevated ozone levels.