Interspecific variation in the fruit infestation level by <i>Anastrepha fraterculus</i> and <i>Ceratitis capitata</i> in northwestern Argentina mirrors the types of land use and host plant origin

Abstract Invasive fruit flies have the potential to exert a profound influence on agroecosystems, given their capacity to displace native species and modify host-use dynamics. In northwestern Argentina, Anastrepha fraterculus and Ceratitis capitata are the most significant fruit fly pests. This study synthesised infestation data by A. fraterculus and C. capitata on host plant species in northwestern Argentina, and explored how land use and altitude modulate infestation patterns. The findings demonstrated that A. fraterculus exhibited significantly higher and more variable infestation levels, particularly on native hosts belonging to the families Myrtaceae and Juglandaceae. Infestation levels exhibited significant variation among the landscape units, increasing with altitude. Conversely, C. capitata exhibited lower and more homogeneous infestation levels, with no substantial disparities related to host plant origin or landscape unit, although a notable non-linear relationship with elevation was observed. The findings indicate ecological niche partitioning between the two species and highlight the necessity of integrating host use, environmental gradients, and landscape context into fruit fly management. By integrating biotic and abiotic drivers of infestation across multiple environmental contexts, our systematic study provides a novel, landscape-scale perspective on the ecology of both native and invasive fruit flies, suggesting practical implications for improving pest surveillance and control strategies through habitat-based approaches tailored to species-specific ecology.