Abstract
Several fruit fly species in the Drosophilidae and Tephritidae families are classified as invasive pests worldwide. However, limited information is available on the occurrence of those dipteran species, their interactions, and their host plants in the Pampa Biome of southern Brazil. Therefore, we investigated interactions between invasive fruit flies and host plants. After two years (2022-2023) of fruit surveys, 3802 fruits from 16 plant species were harvested in the Pampa Biome's urban and rural areas. The collected fruits were conditioned in the laboratory. Emerged adult flies were identified and associated with the respective fruit species. The most abundant species detected were Zaprionus indianus (Gupta), followed by Zaprionus tuberculatus (Malloch), Drosophila suzukii (Matsumura), and Ceratitis capitata (Wiedemann). The invasive drosophilids D. suzukii, Z. indianus and Z. tuberculatus interacted with 10 host plant species each, whereas C. capitata was associated with seven host species. Zaprionus indianus showed the highest infestation rate on fruits collected from the ground, whereas D. suzukii had the highest infestation rate in fruits attached to plants. New host plants were identified for Z. tuberculatus and C. capitata. The findings of this study provide a valuable framework for more effective management and control strategies.