## 4 Discussion
### Determining the Spatial and Temporal SIT Opportunity Window  
It is important to bear in mind that at a local scale, the way the SIT method works is quite different from typical IPM methods such as cover spray pesticide application, mass trapping or bait sprays. The operation of the latter is spatially limited to the areas of their application, and medflies stay susceptible to them throughout their lifetime, regardless of age and mating status. In contrast, the area of activity of the released sterile males is less defined because they disperse freely after release and, like wild individuals of the target population, follow the seasonally changing spatial distribution of available resources [19]. Typically, large SIT operations are guided by medfly monitoring, which shows the presence and density of flies in the treated area [10]. However, it is not the number of flies present that determines the optimal timing of SIT intervention, but their physiological state. Practically, only newly emerged wild female flies are briefly susceptible to SIT. When planning SIToperations, it is important to remember that SIT releases will have no effect either before or after the time at which new females emerge and reach maturity. Understanding the relationship between windows of susceptibility to SIT at the individual insect and population levels and its relationship to the phenology of locally available fruits is crucial for the implementation of SIT. Newly emerged, wild medfly females become sexually mature and ready to mate several days after emerging from the soil [52]. In general, most females mate only once, although infrequent re-mating occurs [40; 41]. Thus, apart from these rare cases, for individual females, their temporal \"window of vulnerability\" to SIT is limited to just one day, at which point the female chooses to mate with either a wild or sterile male. For the population as a whole, consisting of many cohorts of females of different ages, the length of the temporal window for SIT operations is much longer. Its length is determined by the emergence time of new cohorts of virgin females, which in turn depends on the seasonal continuity of the availability of fruits suitable for larval development [51]. Although fruits are usually most attractive near ripeness, they can be infested at or even earlier than their \"green maturity stage\" and in some cases, at the very early, fruitful stage [53]. Although not at their optimal suitability, such unripe fruits can still support some larval development. This means that for each fruit phenological category, the time window in which medfly can develop is much wider than the fruit ripening period preceding harvest. In the highly fragmented mosaic landscapes typical of European fruit growing [54; 55], the long lifespan and considerable mobility of wild medflies allows individuals to move between different plots during the season according to the phenology of local fruits [56; 57; 58; 59; 60]. Consequently, the exact locations (specific plots) where cohorts of successive generations emerge, where individual females disperse and mate, and where they lay eggs and cause fruit damage, are often different and seasonally variable. Under such circumstances, ensuring temporal and spatial convergence between wild and briefly SIT-vulnerable ready-to-mate females and short-lived sterile males, which is crucial for SIT success, is challenging and requires precise planning. The model reflects these processes by simulating the development of both medfly and fruit development according to local weather conditions, as well as seasonal movement of medfly between plots containing fruits with different phenology. This allows the model to generate locally relevant information on the optimal timing and spatial targeting of local SIT activities.