Biological control of Diptera in agri-food system

This study explores sustainable biocontrol to mitigate pests which can affect Italy's agri-food system: Piophila casei Linnaeus (Diptera: Piophilidae) and Drosophila suzukii Matsumura (Diptera: Drosophilidae), which threaten cured meats and small fruits, respectively. Chapter One optimized P. casei rearing and its parasitoids, Pachycrepoideus vindemiae Rondani and Muscidifurax raptor Girault & Sanders (Hymenoptera: Pteromalidae). Three diets (infant formula, milk powder, dry ham) were tested on P. casei. Dry ham accelerated development, while infant formula increased longevity and growth. The second part assessed parasitism success (SP), degree of parasitism (DP), sex ratio (SR), development time (DT), longevity (LO) and emergence rate (ER) for the two parasitoids through laboratory trials. Both had low ER, affecting DP and SP, while SR was female-biased. The final section evaluated freezing P. casei pupae at -20°C for 14–56 days on P. vindemiae rearing. Extended storage reduced ER, increased non-attraction (NA), and caused pupal decay, affecting parasitoid quality. However, DT, LO, and F2 generation quality were unaffected when emerging from fresh pupae. Chapter Two examined P. vindemiae and M. raptor releases in a ham facility. Data included total parasitism (TP), ER, SR, and LO. While LO and SR showed no significant differences, P. vindemiae had higher TP and ER, making it the superior biocontrol candidate. Chapter Three presents a non-destructive method to detect P. casei in dry-cured ham using an electronic nose to identify infestation volatiles. Tests scaled from 1 g to 500 g and whole hams (~9 kg). PCA analysis showed 80% accuracy with 1 g, 64% with 500 g, and 60% with whole hams. Chapter Four assessed D. suzukii control in Emilia-Romagna, focusing on Ganaspis kimorum Buffington (Hymenoptera: Figitidae) release. Monitoring 20 sites (2022–2023) evaluated its impact. G. kimorum overwintered and parasitized D. suzukii in 2022 but was absent in 2023.