Under enriched ozone levels, gravid P. xylostella females did not discriminate between plants exposed to volatiles from damaged and undamaged neighbors. Ozone can interfere with volatile mediated interactions in several ways. Firstly, ozone could have altered the susceptibility of a plant to oviposition by altering foliage quality (Vuorinen et al., 2004), resulting in gravid females assessing both ozo-ir-VOC and ozo-cr-VOC plants as similar quality hosts. Secondly, ozone could have degraded the volatile signal by reacting with the VOCs transported in the air.