Impact of the Mediterranean fruit fly (Medfly) Ceratitis capitata on different peach cultivars: The possible role of peach volatile compounds

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 susceptible 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 acetate, 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 medfly pheromone and attractant respectively, was found in the least susceptible cvs .