Laboratory and field studies on the effect of ozone, sulfur dioxide and nitrogen dioxide on Lepidoptera pheromones

Pheromones serve as chemical messengers between members of the same species. Past studies have suggested that anthropogenic air pollutions have a negative effect on pheromones. Further experiments concerning this question such as chemical analysis and field investigations are presented here. Gas chromatographic analysis revealed the degradation of the pheromone of Eupoecilia ambiguella HE. (Lepidoptera, Tortricidae) and of Adoxophyes orana F.V.R. (Lepidoptera, Tortricidae) and the existance of break down products during ozone fumigation (120-360 mu g/m(3)). Nitrogen dioxide (240 mu g/m(3)) had a less effect. Sulphur dioxide (320 mu g/m(3)) was not able to attack these pheromones. The effect of ozone on capture rate of sex pheromone traps used to monitor Adoxophyes orana was investigated. Field experiments showed that ozone in high summer concentrations (400 mu g/m(3)) reduced the capture rate of modified pheromone traps. Significantly fewer moths were captured in traps fumigated with ozone than in those which received charcoal filtered air. The possible consequences are discussed.