Flight characteristics of <em>Bactrocera dorsalis</em> associated with long-distance migration

Recently, individuals of the oriental fruit fly and its relatives (Bactrocera dorsalis species complex)—previously eradicated in Japan—have occasionally been captured in surveillance traps in the Kyushu District of western Japan, posing an increasing risk to agricultural industries. This emerging situation necessitates the development of a migration prediction model to provide early warnings of their arrival, for which understanding the species’ flight characteristics is essential. In this study, flight experiments were conducted using young first-generation adults that emerged from larvae collected in Taiwan. Outdoor observations revealed that B. dorsalis actively initiates flight around 10:00 and sunset. Flight mill experiments under varying temperature conditions indicated that flight activity ceased at temperatures between 16.2 and 16.5 °C. Furthermore, a 24-hour flight test demonstrated that some individuals were capable of sustaining flight for over 7 hours, suggesting a potential capacity for long-distance migration. These findings contribute to the development of a migration prediction model and enhance our understanding of the flight behavior associated with long-distance migration in B. dorsalis.