Impact of the Mediterranean fruit fly (Medfly) Ceratitis capitata on different peach cultivars: The possible role of peach volatile compounds Maria Rosaria Tabilio a , Dennis Fiorini b,⇑ , Enrico Marcantoni b , Stefano Materazzi c , Maurizio Delfini c , Flavio Roberto De Salvador a , Sergio Musmeci a,d a Agricultural Research Council, Fruit Tree Research Center, Rome (Consiglio per la ricerca e la sperimentazione in agricoltura, Centro di ricerca per la frutticoltura – CRA-FRU – Roma), V. Fioranello 52, I-00134 Rome, Italy b University of Camerino, School of Science and Technology, Chemistry Division, V.S. Agostino 1, I-62032 Camerino (MC), Italy c La Sapienza University, Chemistry Department, P. Aldo Moro 5, I-00185 Rome, Italy d Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA),Technical Unit for Sustainable Development and Innovation of Agro-Industrial System (UT-AGRI), V. Anguillarese 301, S. Maria di Galeria, I-00123 Rome, Italy article info Article history: Received 1 November 2012 Received in revised form 18 December 2012 Accepted 18 February 2013 Available online 27 February 2013 Keywords: Ceratitis capitata Pheromones Peach cultivars Volatile composition Insect tolerance SPME–GC–MS abstract The relationship between susceptibility of different peach cultivars (cvs) to the Mediterranean fruit fly (medfly), Ceratitis capitata, and the volatile composition of ripe fruit of each cv has been investigated, since understanding the fruit-insect interaction mechanism is crucial for developing control strategies for such a pest. Volatile compounds were analyzed by SPME–GC–MS in three cvs highly susceptible to medfly attack (Fair Time, Flaminia, Sicilia Piatta), and in two less susceptible cvs (Percoca Romagnola 7 and Doctor Davis). Among the volatile compounds detected, 88 could be identified. The main differences found in the volatile composition of the cvs, concerned the relative abundance of esters. The least suscep- tible cvs, above all Percoca Romagnola 7, contained the higher amounts of hexenyl, hexyl, 3-methylbutyl, butyl and 2-methylpropyl esters; among these, some C 6 derivatives detected, such as (Z)-3-hexenyl ace- tate, are known to act as priming agents, enhancing plant defence response to insects. Instead, a lower relative content of methyl esters, such as methyl hexanoate and methyl octanoate, known to act as med- fly pheromone and attractant respectively, was found in the least susceptible cvs. Ó 2013 Elsevier Ltd. All rights reserved. 1. Introduction Ceratitis capitata Wiedemann (C. capitata) is a fly which, in the larval stage, feeds on a wide variety of fruits and can affect about 250 different species (Tremblay, 1994). C. capitata has the ability to adapt to a wide variety of environmental conditions, which causes concern in zones not yet colonized and thus potentially at risk (Fimiani, 1989). Currently, medfly control is done, almost exclusively, with chemicals that are harmful for human health and the environment (Bolognesi & Merlo, 2011). In organic fruit production, the problem is even more serious, since European law regarding organic farming prohibits the use of synthetic sub- stances. For this reason, growers tend to limit the problem by avoiding medium-late varieties cvs, preferring early season cvs, which mature before fly damage occurs. Given the seriousness of this problem, ninety peach cvs were evaluated for their suscep- tibility to medfly, during the 2006–2009 season, in a research program carried out at the Fruit Tree Research Center near Rome (Italy). From the results obtained in field and laboratory tests, a few cvs were identified as being less susceptible to fly damage. Several authors have demonstrated how fruit of different cvs have a different profile of volatile compounds and how the release of these compounds increases or decreases during the ripening pro- cess (Horvat et al., 1990; Wang et al., 2009). For example, it has been found that some substances, such as lactones and open chain esters are found in higher concentrations during ripening (Hernandez, Vargas-Arispuro, Adelantado, & Primo-Yufera, 1999; Visai & Vanoli, 1997). Repeated field observations confirm that there is a clear preference of the medfly for nearly ripe fruit. This has been confirmed by Hernandez et al. (1999) in electrophysio- logical studies, where the greatest electroantennography (EAG) response occurred for nearly ripe fruit. This leads to the hypoth- esis that, though C. capitata is quite adaptable and able to feed on many kinds of fruit, the preference for some cvs over others could be due to different profiles of volatile compounds in their fruit. In this paper, the results for two less susceptible and three more susceptible peach cvs will be shown, and the possible relationship between the susceptibility to medfly and profile of volatile com- pounds, with potential effects on C. capitata’s behaviour, will be explored. 0308-8146/$ - see front matter Ó 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.foodchem.2013.02.074 ⇑ Corresponding author. Tel.: +39 0737 402254; fax: +39 0737 402297. E-mail address: dennis.fiorini@unicam.it (D. Fiorini). Food Chemistry 140 (2013) 375–381 Contents lists available at SciVerse ScienceDirect Food Chemistry journal homepage: www.elsevier.com/locate/foodchem