The development of drosophilid species (Diptera, Drosophilidae) in different strawberry cultivars.
Introduction - Drosophilids were not considered to be agricultural pests as they usually developed in overripe and fermented fruits. With the arrival of the invasive species Drosophila suzukii (Matsamura, 1931) in Europe the pest status of drosophilids changed as the species are able to develop in healthy, unwounded and soft-skinned fruits of commercial value. The first economic damages from D. suzukii in Croatia were observed in the commercial production of fresh market strawberry in 2014. The aim of this study was to determine species of drosophilids that can develop in strawberry fruits and to explore their preference between different cultivars in production. Materials and methods - The samples of fruits of three strawberry cultivars ('Albion', 'Portola' and 'San Andreas') were collected in 2016 from a greenhouse farm near Zagreb (45°41'24"N, 16°24'0"E). From each cultivar 50 samples of fully ripened fruit were randomly selected and placed into the chamber for insect development at a specific temperature and humidity regime. Results and discussion - After development of flies, three drosophilid species: Drosophila immigrans Sturtevant, 1921; D. simulans Sturtevant, 1919 and D. suzukii were identified. An analysis of variance showed statistically more drosophilids in the 'Albion' cultivar compared to the other two cultivars examined. Conclusion - Species D. immigrans and D. simulans can also develop in strawberries and cause economic damage to strawberry production if the fruits were primarily damaged by D. suzukii. Finally, drosophilids prefer the 'Albion' cultivar for breeding.