Mating disruption (MD) is widely used against the European grapevine moth (EGVM), Lobesia botrana (Denis and Schiffermüller; Lepidoptera: Tortricidae), by installing passive dispensers or aerosol devices. The present work reports a new sampling and quantification methodology to obtain absolute data about field airborne pheromone concentration based on air samplings and sensitive chromatographic-spectroscopic methods. Samplings were performed in fields treated with passive dispensers or aerosol devices at different moments throughout the crop cycle to study how they act and how the disruption is triggered. Moreover, pheromone adsorption and releasing capacity of vine leaves were studied to elucidate their role in the disruption. Although both types of dispensers were effective in limiting the damage inflicted by EGVM, they performed differently and provided different airborne pheromone concentration profiles. Results also proved that leaves were able to adsorb and release part of the airborne pheromone acting as subsequent and additional pheromone sources. This fact could explain the different concentration profiles. Moreover, our results suggest that lower pheromone emission than that of the current passive dispensers still could provide an adequate performance in the field. Competitive mechanisms involved in MD using both dispensers, the dynamics of the airborne pheromone throughout the time and the importance of the canopy are discussed.

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The role of desensitization in mating disruption (MD) of European Grapevine Moth (EGVM), Lobesia botrana (Dennis and Schiffermüller) (Lepidoptera: Tortricidae), is studied by exposing males to different airborne pheromone concentrations for various time intervals prior to evaluate their behavioural response. By using different types of dispensers, male moths are exposed to three decreasing pheromone concentrations (up to the minimum concentration able to desensitize them) for 1, 3, and 24 h. The airborne pheromone concentration present in all treatments is accurately quantified using gas chromatography–mass spectrometry equipment to compare these data with actual airborne pheromone concentrations under field conditions. The effect of pheromone exposure on L. botrana males is studied in wind tunnel and electroantennogram assays, immediately and 24 h after the exposure period. Results show that the reduction of response to the pheromone depended on the dose and the duration of the treatment, but the lowest dose tested did not produce desensitization. These results support that the most important mechanisms of MD acting in fields treated against EGVM are the competitive ones and that the non‐competitive ones only may become relevant very close to pheromone dispensers. Our results support the hypothesis of cross‐adaptation to other chemical stimuli in the pre‐exposed moths to their pheromone although more studies are needed to draw stronger conclusions.

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