The enemy is already inside! Bactrocera dorsalis is a serious threat to European orchards and crops

The invasive spread of the Bactrocera dorsalis (Hendel), (Diptera, Tephritidae) (the oriental fruit fly), is inten- sifying globally. After sporadic interceptions in Europe, the first field findings occurred in Italy in 2018–2019. Despite a record-free period from 2020 to 2021, catches in Campania surged from June 2022 onwards. In response, a series of research activities began in Campania, aiming to delineate the infested zone, evaluate dispersion, assess population dynam- ics, identify the epicenter, and determine prevalent host fruits. Over 250 traps of various types, baited with diverse attrac- tants, along with fruit samplings, led to the capture of the first B. dorsalis females and the identification of the first active infestation in Europe during the summer of 2022. Results reveal a rapid increase in captures from June 2022 to January 2023, with over 3,000 adults captured, reaching the peak in October. The expansion of the infested zone reached 48.24 km2 , indicating a localized hotspot. Active infestations primarily occurred in specific locations, with Citrus spp. being the most frequently infested fruits. The sex ratio of captured specimens indicates a bias towards males, particularly due to the lure used. The study identifies a narrow 14.04 km2 area, concentrating 97.4% of catches, as the probable epicenter. Specific anthropized localities play a crucial role in sustaining the population. Bactrocera dorsalis specimens exhibited a potential movement range of about 7 km, but the movement of infested fruits can greatly expand this range. The high number of recorded catches suggests the existence of a substantial nucleus of individuals, possibly facilitating the acclimatization of the species in Italy.