## 2 Materials and Methods
### Evaluation of Calliophora Vomitoria Oiposition Deterrence on Beef Loaves  
To prepare the beef loaves, we used the same minced beef as for the beef patties. Approximately 470 g (469.49 \(\pm\) 1.94 g; mean weight \(\pm\) SD, \(n\) = 12) of meat was weighed on the precision balance and manually shaped in prolate spheroidal loaves (height 28.02 \(\pm\) 1.40 cm, length 12.60 \(\pm\) 0.68 cm; mean measures \(\pm\) SD, \(n\) = 12; surface \(\cong\) 1109 cm\({}^{2}\)). A total of 12 beef loaves was prepared (three samples for each of the four treatments). The three untreated (control) loaves were individually wrapped in elastic, tubular cotton netting to maintain their shape and kept at room temperature for 60 min. The treated loaves were first wrapped in the netting, immersed for 30 s in the respective treatment (three in the 1.0% CH solution, three in the _L. nobilis_ EO-enriched CH solution, and three in the _P. nigrum_ EO-enriched CH solution), placed on a plastic mesh grill to allow the excess solution to drip off, and left to dry for 60 min. Using the precision balance, we determined that the weight of the CH or CH+EO covering was 28.22 \(\pm\) 0.20 g (mean weight \(\pm\) SD, \(n\) = 9). Therefore, we can assume that the amount of EO was 0.25 \(\mu\)L EO cm\({}^{-2}\) of surface.  
The rearing of _C. vomitoria_ was maintained under laboratory conditions (23 \({}^{\circ}\)C, 60-70% RH, natural photoperiod 12/12 h day/night). In accord with the procedure used by [PERSON] et al. [20], mature larvae were purchased from a commercial supplier of live fishing baits (Nonno Ippei, Vittoria Apuana, Italy) and kept in polypropylene boxes (27 \(\times\) 21 \(\times\) 12 cm) with a netted lid for ventilation until pupation. The pupae were then transferred into 75.0 \(\times\) 75.0 \(\times\) 115.0 cm knitted mesh and polyester tents (BugDorm-2400 Insect Rearing Tent, MegaView Science Co., Ltd., Taichung, Taiwan), which were provided with _ad libitum_ water and a sucrose + yeast extract (4:1 \(w/w\)) solid diet for the emerging adults. Yeast extract was used as a protein source to support oviposition [32]. Species identification was carried out on twenty randomly selected adults using the specific identification keys [33].  
The deterrence exerted by the proposed treatments against oviposition by _C. vomitoria_ females was evaluated using the beef loaves randomly hung (wire length 12.0 cm) from the ceiling of a netted polytunnel (width 4.0 m, length 10.0 m, peak height 2.0 m). The polytunnel was located in the garden of the Entomology Laboratory of the Department of Agriculture, Food and Environment (University of Pisa, Pisa, Italy). For the trial, it was equipped with water sources and landing surfaces for the blowflies. The netted cover prevented the entry of other insects and the escape of our blowflies.  
At T0, we released 150 _C. vomitoria_ adults of undetermined sex (15-20 days old, sex ratio 1:1) inside the polytunnel to simulate a work environment where good manufacturing practices are not followed. After 48 h (T1), we collected all the egg masses laid on the loaves and weighed them on an analytical balance (KERN ABS-N, Kern & Sohn, Balingen, Germany). The seven blowflies found dead were removed and replaced to maintain a total of 150 specimens in the tunnel. All the loaves were then hung back in their original positions. The egg masses were collected and weighed again at T2 (after 96 h from the beginning of the trial). To calculate the total number of eggs laid, we determined the average weight of a single _C. vomitoria_ egg.  
The trial was conducted in March 2023, with a mean minimum temperature of 8.2 \({}^{\circ}\)C and a mean maximum temperature of 16.8 \({}^{\circ}\)C [34]. We selected this month to ensure that the mean daily temperature was above 13 \({}^{\circ}\)C, which is considered unsuitable for meat product preservation during most processing activities. The natural photoperiod at that time in Pisa was 12/12 h day/night.