Oviposition strategies and interactions among invasive and native fruit flies (Diptera: Tephritidae) on guava (Psidium guajava L.)

Oviposition and agonistic behaviour are important traits for understanding the pattern of coexistence and choice of host fruit shared between natives and invasive species. This study aimed to evaluate the interspecific interactions and the choice of the oviposition sites among three native species of fruit flies of the genus Anastrepha : Anastrepha obliqua (Macquart), Anastrepha fraterculus (Wiedemann), Anastrepha sororcula Zucchi, and an invasive species, Ceratitis capitata (Wiedemann). The interactions between species were measured by counting the number of eggs laid in semi‐ripe and ripe guavas ( Psidium guajava L.) in intra and interspecific combinations. Additionally, we compared the absolute frequency of agonistic behaviours in interactions between native and invasive fruit flies. The native species of Anastrepha did not change their preference for the fruit ripening stage, even in face of the invader C. capitata . Anastrepha species and C. capitata preferred to oviposit in semi‐ripe fruits, in all experimental scenarios. We also observed that C. capitata avoided interactions with the native species by preferring to oviposit in ripe fruits when in the presence of Anastrepha species. All species reduced the number of laid eggs when in the presence of heterospecific females. Aggression was the most frequent agonistic behaviour in all species combinations, followed by display/stalking and avoidance. Finally, our results showed that aggression behaviour was the most frequent in interactions of Anastrepha species with C. capitata .