Thermal acclimation and environment drive field dispersal patterns of adult Mediterranean fruit flies

Abstract Dispersal is a key ecological process influencing population persistence, range expansion and species responses to environmental change. Temperature has a direct impact on insect dispersal through its effects on physiology and behaviour, and prior exposure to various thermal regimes can further alter performance through phenotypic plasticity. We investigated how thermal acclimation, ambient temperature and habitat characteristics influence field dispersal of the Mediterranean fruit fly, Ceratitis capitata (Diptera: Tephritidae), using mark–release–recapture experiments conducted across seasons in orchards with and without host plants. Ambient temperature was a strong predictor of recapture success in both sexes, with capture rates increasing significantly as field temperatures increased. Female recaptures were 2.6 times higher in orchards containing host plants, whereas male recaptures were unaffected by host presence. Males exhibited a significant decline in recapture rates with increasing distance from the release point, while female captures were more strongly associated with host availability than with distance. In contrast, thermal acclimation at 20°C, 25°C or 30°C had no detectable effect on recapture rates or dispersal patterns. Our findings indicate that immediate environmental conditions and resource availability exert a stronger influence on medfly dispersal than recent thermal history. More broadly, these results suggest that short‐term behavioural responses to local environmental conditions may be more important than acclimation effects in determining movement patterns of highly invasive insect species, with implications for predicting pest spread and improving monitoring and management strategies under changing climates.