Electroantennographic and Behavioural Responses of European Cherry Fruit Fly, Rhagoletis cerasi, to the Volatile Organic Compounds from Sour Cherry, Prunus cerasus, Fruit

Simple Summary The larvae of European cherry fruit flies are developing in sweet and sour cherry fruit. Non-insecticidal methods to control this pest are needed since most of the conventional insecticides used have been banned in Europe. Mass trapping is one of the environmentally friendly methods, however, it requires highly effective pest attractants. Three volatile compounds were identified as attractive to females of this species. European cherry fruit fly, Rhagoletis cerasi (Diptera: Tephritidae), is the most important pest of sweet and sour cherry fruit. This fly is difficult to control by insecticide application since most of the conventional insecticides used have been banned in Europe. Traps are used for both the pest's mass trapping and the detection of the beginning of the flight period. Data on flies' reactions to host-plant volatile organic compounds (VOCs) can be used to search for new attractants. VOCs were collected from the headspace of sour cherry, P. cerasus, fruit. Gas chromatography-mass spectrometry (GC-MS) resulted in the identification of 51 compounds. Terpenes and esters predominated in two aspects: in the highest diversity of the compounds, and the amount of the total VOC emissions (62.3%). Among the single VOCs, ethyl octanoate prevails, followed by (E)-4,8-dimethyl-1,3,7-nonatriene. GC-electroantennographic detection (GC-EAD) revealed 14 EAG-active compounds and those were identified. In Y-tube olfactometer tests, EAG-active compounds ((E)-beta-ocimene, linalool, and (Z)-3-hexenyl 3-methylbutanoate) attracted R. cerasi females in a similar way to the odour of sour cherry fruit.