Ozone exposure disrupts insect sexual communication

Insect sexual communication often relies upon sex pheromones. Most insect pheromones, however, contain carbon-carbon double bonds and potentially degrade by oxidation. Here, we show that frequently reported increased levels of Anthropocenic ozone can oxidize all described male-specific pheromones of Drosophila melanogaster , resulting in reduced amounts of pheromones such as cis-Vaccenyl Acetate and ( Z )−7-Tricosene. At the same time female acceptance of ozone-exposed males is significantly delayed. Interestingly, groups of ozone-exposed males also exhibit significantly increased levels of male-male courtship behaviour. When repeating similar experiments with nine other drosophilid species, we observe pheromone degradation and/or disrupted sex recognition in eight of them. Our data suggest that Anthropocenic levels of ozone can extensively oxidize double bonds in a variety of insect pheromones, thereby leading to deviations in sexual recognition. Insect pheromones can be degraded by the air pollutant ozone. Jiang et al. show that ozone-exposed male flies lose their pheromones and become less attractive to females. Additionally, ozone-exposed males exhibited increased male-male courtship behaviour as a result of reduced sex recognition.