Abstract: Mass trapping can be a powerful tool for the control of the Mediterranean fruit fly (medfly), Ceratitis capitata (Diptera: Tephritidae), and other fruit flies of high economic importance. Here we present results of using the new female specific attractant Biodelear for the mass trapping of C. capitata in citrus orchards in the Campos area of Chios. The results form part of a five-year LIFE programme aimed at developing an integrated strategy for the management of this serious pest. The study was conducted from September to December 2015. Mass trapping was performed in four 0.5 ha plots using 50 plastic McPhail traps per plot baited with 17 g of Biodelear. For comparative purposes, we included in the study three additional plots with traps baited with the “standard”, commercially available attractant Biolure® (Suterra LLC, Bend, OR, USA). Likewise, we included four conventional plots treated with insecticides, as well as three organic plots receiving no treatments to serve as control. The experimental plots were separated from one another by 10 m wide buffer zones treated with insecticides. The efficacy of mass trapping was evaluated by monitoring the level of C. capitata population using five separate McPhail traps baited with Biolure and five Jackson traps baited with trimedlure per plot. We also monitored infestation rates by sampling and examining large numbers of fruits for oviposition stings and emerging pupae. Finally, to assess the environmental impact of each treatment, we monitored ground biodiversity of arthropods using pitfall traps. The results showed that mass trapping with Biodelear resulted in a substantial reduction of the population of C. capitata compared to the organic control treatment. Although Biolure initially appeared to be better, later in the season the two attractants converged in efficacy. A similar pattern was observed in the results concerning the infestation of sweet oranges and mandarin oranges. In both the Biodelear and Biolure treatments these fruits were significantly less infested compared to the organic control treatment. Although Biolure appeared to be slightly better than Biodelear the two treatments did not differ statistically. Finally, in both the Biodelear and the Biolure treatments the diversity of ground arthropods was similar as in the organic control and significantly higher relative to the conventional insecticide treatment. These first results of the LIFE programme strongly suggest that mass trapping with the new attractant Biodelear can effectively control the population of C. capitata, lower citrus fruit infestation and preserve biodiversity of arthropods. The results are particularly encouraging given the much lower cost and negligible toxicity of Biodelear compared to Biolure.